General discussion and questions about my tank because I am noob at this

[ISpeakForTheSeas]

The Prawn might be dead. I did a water change before adding the prawn, so before we left the beach I refreshed the water the prawn was in so it had enough oxygen but because I had surgery recently I couldn't carry it so my dad had to. He didn't want to get up when we were home so it ended up being an extra hour before it was in the tank water, and it wasn't moving. I think it needs some time to breath but it has been like 5-6 mins and it is still not moving I am really scared. The Corbina is bigger than most stuff in the tank and absolutely loves the tdo chroma boost, it has a small mouth, too small to fit anything that lives in there into it's mouth. My mom and dad do not want to spend a lot of money on a 50 gallon tank and we just found a 55 gal for 100 dollars and my dad is on board with it and is waiting for mom's confirmation to get the tank. That is huge and will be great for my creatures, very soon will I get my hands on that tank and then I will get baby sand crabs to feed my corbina because they love sand crabs. I just fed my Dungeness crab a meal worm and thought it was done because he was in the sand and I couldn't see the worm but when I was about to feed him another he made the one he was eating visible so I can see like he was saying "hey, I'm not done yet!" those creature are so smart and I can't wait to upgrade my tank again. It started 5 gallons, then 10, and now 20, and it is about to be 50, then 100, then multiple 50's and 100's and a massive 200-300 tank. Only time will tell how far I will get.
my mom wants me to get into farming fish I forgot the names but it is really profitable. I am into aquarium tanks for fun but that would be fun too. At the beach today a spear fishermen appeared in front of me suddenly while I was netting fish and he had a massive halibut and then suddenly a big octopus went on his leg and he was afraid of the octopus, it was wild.

I’d give the prawn a few hours before deciding it’s dead - sometimes in cases like this the animal will seem to be in bad shape for a while before turning out absolutely fine.

Glad to hear the corbina should coexist with the rest of the tank peacefully. I’ve heard that corbina feed by taking mouthfuls of sand to find food, then spitting the sand out through their gills - I don’t know if you’re seeing that, but it sounds like it’d be fun to watch.

Yeah, sand crabs are enjoyed by quite a few things in nature, and a lot of these creatures are smarter than we tend give them credit for.

Good luck with the upgrade - a bigger tank is always appreciated by the fish.

Fish farming is called Aquaculture - it can be a bit tricky and the tanks are setup/run a bit differently than regular hobbyist tanks (especially if they’re commercial food fish aquaculture tanks), but I’m hoping to do some small-scale aquaculture of aquarium fish in the future myself (it sounds fun to me). It can be pretty profitable depending on how it’s done and what species are farmed, but I wouldn’t expect to get rich with it, as taking care of all the fish and tanks while waiting for the fish to grow up enough to be sold can really eat into the profits.

That sounds like a very memorable trip to the beach - especially for the fisherman!

 

[Amethyst]

The prawn is dead. It has the same gill injuries as how the ghost shrimp died, there is something in that water that is getting them and I don't know what

 

[ISpeakForTheSeas]

The prawn is dead. It has the same gill injuries as how the ghost shrimp died, there is something in that water that is getting them and I don't know what

Are they being preyed on by something in the tank? I know you mentioned the shrimp’s head popping off before - did it actually pop off (i.e. did it just fall off on its own)? Or did something take it off?

Also, how is the water quality- any ammonia, copper, etc. in the tank?

 

[Amethyst]

Also, how is the water quality- any ammonia, copper, etc. in the tank?

I did a completely full water change of like all the water before that with fresh sea water so it is normal and the water quality should be perfect because it is the water I got them from

 

[Amethyst]

Are they being preyed on by something in the tank? I know you mentioned the shrimp’s head popping off before - did it actually pop off (i.e. did it just fall off on its own)? Or did something take it off?

Before that was the case probably because the shrimp's soft bodies but this one was almost all the way off with a big split on the back too but it wasn't off completely

 

[ISpeakForTheSeas]

Before that was the case probably because the shrimp's soft bodies but this one was almost all the way off with a big split on the back too but it wasn't off completely

Hmm. Injury and disease really aren't my area of expertise, so while I might guess predation of some kind, maybe we can get a second opinion here.

The link below tells what information to share to try and get some help from the experts on the forum here to figure out diseases/injuries/other problems in a tank. I'd recommend posting the necessary information here, and then we can tag some experts to see if they can help figure out what's wrong.

Some Helpful Hints When Posting or Responding to Threads in the Fish Disease Treatment and Diagnosis Section

Aquarium Fish Disease Problem Solving Determining the best course of action for a problem with your aquarium can be a difficult task. Even advanced aquarists will often need to seek the help of others for complicated or unique issues. Our intent here on Reef 2 Reef is to offer expert advice...

www.reef2reef.com

 

[Amethyst]

Hmm. Injury and disease really aren't my area of expertise, so while I might guess predation of some kind, maybe we can get a second opinion here.

The link below tells what information to share to try and get some help from the experts on the forum here to figure out diseases/injuries/other problems in a tank. I'd recommend posting the necessary information here, and then we can tag some experts to see if they can help figure out what's wrong.

Some Helpful Hints When Posting or Responding to Threads in the Fish Disease Treatment and Diagnosis Section

Aquarium Fish Disease Problem Solving Determining the best course of action for a problem with your aquarium can be a difficult task. Even advanced aquarists will often need to seek the help of others for complicated or unique issues. Our intent here on Reef 2 Reef is to offer expert advice...

www.reef2reef.com

I think my Dungeness crab might be a red rock crab because recently there has been some black coloring developing on the tips of his claws like a red rock crab

 

[Amethyst]

Hmm. Injury and disease really aren't my area of expertise, so while I might guess predation of some kind, maybe we can get a second opinion here.

The link below tells what information to share to try and get some help from the experts on the forum here to figure out diseases/injuries/other problems in a tank. I'd recommend posting the necessary information here, and then we can tag some experts to see if they can help figure out what's wrong.

Some Helpful Hints When Posting or Responding to Threads in the Fish Disease Treatment and Diagnosis Section

Aquarium Fish Disease Problem Solving Determining the best course of action for a problem with your aquarium can be a difficult task. Even advanced aquarists will often need to seek the help of others for complicated or unique issues. Our intent here on Reef 2 Reef is to offer expert advice...

www.reef2reef.com

ok ty, I might do a complete tank reset with everything like the structure, and the water just in case there is anything bad in the tank. Like move the creatures into a small holding bucket or something and get rid of all the sand and water and add new fresh sand and water so I know for sure something in the water is not killing anything in there because I don't think my crabs claws can do this much damage and sometimes he is under the sand the whole time and when I come back it is too late. It seems to only effect creatures with soft bodies because my Corbina got taken out the same way which is really sad and so I put some smelt in there and just like every other soft bodied creature, it died within 12 hours and I positive the the crab is innocent, even when I do a like 80% water change it still happens which means it isn't the water quality. I really think there is some parasite disease of some sort that is effecting them or something else living in the water to have this happen. Because Temperature is good, Water quality is good, I have 2 powerful air pumps running into a big air stone, and filter working good (double filtration).

 

[ISpeakForTheSeas]

ok ty, I might do a complete tank reset with everything like the structure, and the water just in case there is anything bad in the tank. Like move the creatures into a small holding bucket or something and get rid of all the sand and water and add new fresh sand and water so I know for sure something in the water is not killing anything in there because I don't think my crabs claws can do this much damage and sometimes he is under the sand the whole time and when I come back it is too late. It seems to only effect creatures with soft bodies because my Corbina got taken out the same way which is really sad and so I put some smelt in there and just like every other soft bodied creature, it died within 12 hours and I positive the the crab is innocent, even when I do a like 80% water change it still happens which means it isn't the water quality. I really think there is some parasite disease of some sort that is effecting them or something else living in the water to have this happen. Because Temperature is good, Water quality is good, I have 2 powerful air pumps running into a big air stone, and filter working good (double filtration).

Let me know how the reset goes.

I don’t know that there’s a disease or parasite that would infect both fish and crustaceans or that would cause issues like the ones you described. Since it sounds like the dead creatures aren’t being eaten, it sounds to me like it is probably aggression related - possibly territorial aggression (but, again, I’m not an expert on marine diseases and parasites).

 

[Amethyst]

a few mins till another water change. I have 2 crabs which look like either like red rock crabs or stone crabs or Dungeness crabs. the original one molted once more, it hasn't eaten for a while and it refuses to eat. I tried to feed it a mealworm and even cut the food in half so it could smell the food and it didn't eat, not even the chroma boost stuff it wont eat. so I fed the other crab instead when it didn't eat, AND THEN THE ONE THAT WOULDN'T EAT JUST SPONTAINIOUSLY DROPPED ONE OF IT'S CLAWS FOR NO REASON. the other crab immediately went over and ate the claw that fell off the other crab. The stripped shore crabs are doing fine deep under the sand chillin away from the more dangerous crabs. Ok so something weird is happening with my finger. I was playing with store bought clean clay earlier today and all of a sudden it cut me for no reason somehow. I thought maybe some glass snuck into the clay somehow some way, and here is where it gets crazy. I found a piece of metal that will be used for tank projects that my dad left next to my tank, I picked it up and put it back down. I accidentally spilled some saltwater on the desk stand for the tank and touched the water with my cut finger that I also picked up the metal with, as soon as I made contact it made my cut buzz. Like a shock buzz like electricity but I only felt it in my cut when my finger touched the water or skin near my cut touched the water on the desk touched it, it was weird. I tried touching the tank water with it and nothing happened then I touched one of my crabs with the finger and nothing happened. I did some more investigating, organic matter that is not mine cancels it but dead organic matter makes it 3x worse and more strong of a continuous shock. it only happens for about 15 seconds then goes away for good, but if I grab the metal piece again with the finger I can touch the water on desk for another 15 seconds and it happens, it is unpleasant. Painful even, I don't know how to explain it and can't find anything online. You are good at researching things and I wanted to add this so maybe I could get some sort of an explanation even though this is irrelevant to the conversation.

 

[ISpeakForTheSeas]

a few mins till another water change. I have 2 crabs which look like either like red rock crabs or stone crabs or Dungeness crabs. the original one molted once more, it hasn't eaten for a while and it refuses to eat. I tried to feed it a mealworm and even cut the food in half so it could smell the food and it didn't eat, not even the chroma boost stuff it wont eat. so I fed the other crab instead when it didn't eat, AND THEN THE ONE THAT WOULDN'T EAT JUST SPONTAINIOUSLY DROPPED ONE OF IT'S CLAWS FOR NO REASON. the other crab immediately went over and ate the claw that fell off the other crab. The stripped shore crabs are doing fine deep under the sand chillin away from the more dangerous crabs. Ok so something weird is happening with my finger. I was playing with store bought clean clay earlier today and all of a sudden it cut me for no reason somehow. I thought maybe some glass snuck into the clay somehow some way, and here is where it gets crazy. I found a piece of metal that will be used for tank projects that my dad left next to my tank, I picked it up and put it back down. I accidentally spilled some saltwater on the desk stand for the tank and touched the water with my cut finger that I also picked up the metal with, as soon as I made contact it made my cut buzz. Like a shock buzz like electricity but I only felt it in my cut when my finger touched the water or skin near my cut touched the water on the desk touched it, it was weird. I tried touching the tank water with it and nothing happened then I touched one of my crabs with the finger and nothing happened. I did some more investigating, organic matter that is not mine cancels it but dead organic matter makes it 3x worse and more strong of a continuous shock. it only happens for about 15 seconds then goes away for good, but if I grab the metal piece again with the finger I can touch the water on desk for another 15 seconds and it happens, it is unpleasant. Painful even, I don't know how to explain it and can't find anything online. You are good at researching things and I wanted to add this so maybe I could get some sort of an explanation even though this is irrelevant to the conversation.

Okay, there’s a lot to cover here. First, refusal to eat is rarely a good thing in animals - for larger crabs like the dungeness crab or the red rock crab, I’d recommend feeding things like clams, fish, shrimp, sea snails, etc.; somewhat larger, meaty foods. Since the crab isn’t eating, live food may be best, but a lot of animals may be tempted enough by clam meat regardless of its live or dead that I’d suggest trying that. However, the refusal to eat may be caused by an underlying issue such as disease - that’s a much harder thing to fix. So, I’d try offering it some clam (the varnish clam, Nuttallia obscurata, is known to be preferred by both crabs, but it’s probably not necessary to offer that specific species to them), and if it doesn’t take that then I’d offer it a live shrimp. Supposedly, red rock crabs often eat other crabs, so you could try some crab meat too. If it doesn’t take any of these things, I’d assume it’s sick, and I’d suggest making another post asking if anyone can help with a diagnosis/treatment of the crab.

Second, dropping limbs is something that both red rock crabs, dungeness crabs, and a number of other species can do - it’s called autotomy. It’s typically a self-defense mechanism to avoid predation (they basically sacrifice a limb to escape dying). Something is seriously wrong for your crab to start dropping limbs - it sounds like it may be concerned the other crab is going to kill it, but that’s just my speculation at this point. That said, if the crab feels threatened enough by it’s tankmate, that could be a reason for it to stop eating too.

If you can get the crab eating, eliminate the problem that caused the limb to drop (which may or may not be the other crab), and get the conditions of your tank good enough, then the claw will regrow over the course of a few molts for the crab.

Third, with regards to you finger - that is definitely out of my area of expertise, and I don’t know I can help you much there. If it feels like an electric shock, then that may be what you’re feeling, but I don’t know for sure. To my understanding, our skin normally does a decent job of protecting us from electricity, but if you have a cut that goes through the skin or through enough of the skin, that protection could weaken in that cut area (which could potentially explain why you feel it there and nowhere else); if you mix that weakened protection with saltwater (which, to my understanding again, is more conducive to electricity/weakens your skin’s defense against electricity), it may well be enough to let an electric current that you’d normally be protected from into your system. So, my guess would be that you are coming into contact with stray voltage somehow (if it only happens while you’re touching something specific - like the metal part, for example - then I would assume that’s probably how). This is just a guess though, and - like I said - this is definitely not an area I’m particularly knowledgeable in, so I wouldn’t just assume I’m correct here. Honestly, the only advice I feel I can somewhat responsibly give here is to wash the cut with soap and water and to avoid anything that might cause the shock sensation.

 

[Amethyst]

Okay, there’s a lot to cover here. First, refusal to eat is rarely a good thing in animals - for larger crabs like the dungeness crab or the red rock crab, I’d recommend feeding things like clams, fish, shrimp, sea snails, etc.; somewhat larger, meaty foods. Since the crab isn’t eating, live food may be best, but a lot of animals may be tempted enough by clam meat regardless of its live or dead that I’d suggest trying that. However, the refusal to eat may be caused by an underlying issue such as disease - that’s a much harder thing to fix. So, I’d try offering it some clam (the varnish clam, Nuttallia obscurata, is known to be preferred by both crabs, but it’s probably not necessary to offer that specific species to them), and if it doesn’t take that then I’d offer it a live shrimp. Supposedly, red rock crabs often eat other crabs, so you could try some crab meat too. If it doesn’t take any of these things, I’d assume it’s sick, and I’d suggest making another post asking if anyone can help with a diagnosis/treatment of the crab.

Second, dropping limbs is something that both red rock crabs, dungeness crabs, and a number of other species can do - it’s called autotomy. It’s typically a self-defense mechanism to avoid predation (they basically sacrifice a limb to escape dying). Something is seriously wrong for your crab to start dropping limbs - it sounds like it may be concerned the other crab is going to kill it, but that’s just my speculation at this point. That said, if the crab feels threatened enough by it’s tankmate, that could be a reason for it to stop eating too.

If you can get the crab eating, eliminate the problem that caused the limb to drop (which may or may not be the other crab), and get the conditions of your tank good enough, then the claw will regrow over the course of a few molts for the crab.

Third, with regards to you finger - that is definitely out of my area of expertise, and I don’t know I can help you much there. If it feels like an electric shock, then that may be what you’re feeling, but I don’t know for sure. To my understanding, our skin normally does a decent job of protecting us from electricity, but if you have a cut that goes through the skin or through enough of the skin, that protection could weaken in that cut area (which could potentially explain why you feel it there and nowhere else); if you mix that weakened protection with saltwater (which, to my understanding again, is more conducive to electricity/weakens your skin’s defense against electricity), it may well be enough to let an electric current that you’d normally be protected from into your system. So, my guess would be that you are coming into contact with stray voltage somehow (if it only happens while you’re touching something specific - like the metal part, for example - then I would assume that’s probably how). This is just a guess though, and - like I said - this is definitely not an area I’m particularly knowledgeable in, so I wouldn’t just assume I’m correct here. Honestly, the only advice I feel I can somewhat responsibly give here is to wash the cut with soap and water and to avoid anything that might cause the shock sensation.

How do I get the class or live shrimp? If I go to the beach at low tide I can pull in like 10 little smelt and about 20 little shrimp and a few clams depending on where I am at at the beach, I think I can go in like 1-2 days is that good? O Aldo my dad just got crabbing license so I could use some of the meat.

Ye I know they dropped limbs but I thought it was worth mentioning because normally they only drop limbs when you hold them. But normally only stripped shore crabs drop their limbs and sometimes for no reason they drop like 2 instead of one. But the other type of crabs like red rock crab even when I hold the massive ones by their claws they don't drop them. Come to think of it when I found I baby red rock crab and released it as it was going it dropped its claw and I think it thought I was a predator and that was to distract me.

With the finger problem you were right about everything but one thing, the part where I touched the metal. I wasn't holding the metal, all I did was squeeze it and put it down then went to the water without the metal and then it did the buzz. Depending on how hard I squeezed the metal beforehand is how strong the shock was and it always lasted about 15 seconds.

 

[Amethyst]

The one that wont eat will not eat freeze dried shrimp and the other crab is eating just fine but moving in slow motion and randomly playing dead for no reason. the electric buzz has gone from a little shock to a pain of being cut or stabbed and it made my cut 10x worse.

 

[ISpeakForTheSeas]

How do I get the class or live shrimp? If I go to the beach at low tide I can pull in like 10 little smelt and about 20 little shrimp and a few clams depending on where I am at at the beach, I think I can go in like 1-2 days is that good? O Aldo my dad just got crabbing license so I could use some of the meat.

You can get them from the beach, or you should be able to get clams or shrimp from seafood stores or bait shops (I'm not sure about in California, but at least some seafood stores I know carry live clams, and a lot of bait shops out east carry live shrimp for use as bait).

The one that wont eat will not eat freeze dried shrimp and the other crab is eating just fine but moving in slow motion and randomly playing dead for no reason.

Yeah, the freeze dried isn't nearly as appealing - the way that the prey item moves tends to really entice the predators to eat, so live is usually much more appealing to animals that aren't eating.

With the finger problem you were right about everything but one thing, the part where I touched the metal. I wasn't holding the metal, all I did was squeeze it and put it down then went to the water without the metal and then it did the buzz. Depending on how hard I squeezed the metal beforehand is how strong the shock was and it always lasted about 15 seconds.

the electric buzz has gone from a little shock to a pain of being cut or stabbed and it made my cut 10x worse.

That is odd, and I would suggest 1) don't doing anything to cause the buzz, and 2) talk to a medical professional about the issue.

 

[Amethyst]

You can get them from the beach, or you should be able to get clams or shrimp from seafood stores or bait shops (I'm not sure about in California, but at least some seafood stores I know carry live clams, and a lot of bait shops out east carry live shrimp for use as bait).

Yeah, the freeze dried isn't nearly as appealing - the way that the prey item moves tends to really entice the predators to eat, so live is usually much more appealing to animals that aren't eating.


That is odd, and I would suggest 1) don't doing anything to cause the buzz, and 2) talk to a medical professional about the issue.

how 2 find medical professional, do i go to the doctor?

 

[ISpeakForTheSeas]

how 2 find medical professional, do i go to the doctor?

Yeah - I’d talk with your parents and if they think it’s something to be concerned about, then go see a doctor.

 

[Amethyst]

Ok I just added 2 teaspoons of jungle start right which is auppose to remove chlorine and stuff and also heal damaged skin and fins and I assume it strengthens the immune system to do that so hopefully it helps my crabs not be sick anymore too. I added 1 Ammonia clear fizz tablet to the tank as well. I found one of the bottles that cycles the tank but nowhere on the package did it say it was for saltwater or freshwater so I didn't get it. I got a magnetic algae cleaner and wiped down the outside so the tank looks pristine.

 

[Amethyst]

One of my crabs is back to normal now, the other one is better but still won't eat not even the remains of a pretty much fresh shrimp. because of the chance of rain I can't go to the beach and clams and seafood are too expensive at the store, I think the lobster tails are cheap is that good for the crab? I am going to test a bunch of foods on it. I know it used to not take food from me it would only kill the scallops and clams and muscles and shrimp and eat them. I think the plan is to leave an open clam next to it tomorrow and see if it is eaten in a few hours afterwards because it won't eat in my presence sometimes, it only was like this after I fed it that mealworm then it was like this I think the mealworm made it sick. I will not feed the mealworms to my crabs again, the foods I intend to try to feed it are: Cut fish, dead fish, live fish, plain shrimp tails from the store, live tiny shrimp from the beach, clams, crab bait gel scent (to see if it is attracted), raw chicken, raw beef, maybe some crab food at a fish store, and crab meat. Those are the things I will try to use in an attempt to get it to eat. Thoughts on the list? also why has nobody else come to this thread?

 

[Amethyst]

OMG A MALE GHOST SHRIMP JUST EMERGED REALLY SICK AND BACK ALMOST STARTING TO SPLIT I DON'T KNOW HOW TO HELP HIM PLES TELL ME HOW TO HELP HIM HE HAS BEEN HIDING THIS ENTIRE TIME I DIDN'T KNOW I THINK HE IS HUNGRY I WILL FEED

 

[ISpeakForTheSeas]

Ok I just added 2 teaspoons of jungle start right which is auppose to remove chlorine and stuff and also heal damaged skin and fins and I assume it strengthens the immune system to do that so hopefully it helps my crabs not be sick anymore too. I added 1 Ammonia clear fizz tablet to the tank as well. I found one of the bottles that cycles the tank but nowhere on the package did it say it was for saltwater or freshwater so I didn't get it. I got a magnetic algae cleaner and wiped down the outside so the tank looks pristine.

One of my crabs is back to normal now, the other one is better but still won't eat not even the remains of a pretty much fresh shrimp. because of the chance of rain I can't go to the beach and clams and seafood are too expensive at the store, I think the lobster tails are cheap is that good for the crab? I am going to test a bunch of foods on it. I know it used to not take food from me it would only kill the scallops and clams and muscles and shrimp and eat them. I think the plan is to leave an open clam next to it tomorrow and see if it is eaten in a few hours afterwards because it won't eat in my presence sometimes, it only was like this after I fed it that mealworm then it was like this I think the mealworm made it sick. I will not feed the mealworms to my crabs again, the foods I intend to try to feed it are: Cut fish, dead fish, live fish, plain shrimp tails from the store, live tiny shrimp from the beach, clams, crab bait gel scent (to see if it is attracted), raw chicken, raw beef, maybe some crab food at a fish store, and crab meat. Those are the things I will try to use in an attempt to get it to eat. Thoughts on the list? also why has nobody else come to this thread?

OMG A MALE GHOST SHRIMP JUST EMERGED REALLY SICK AND BACK ALMOST STARTING TO SPLIT I DON'T KNOW HOW TO HELP HIM PLES TELL ME HOW TO HELP HIM HE HAS BEEN HIDING THIS ENTIRE TIME I DIDN'T KNOW I THINK HE IS HUNGRY I WILL FEED

Okay, let's try this again. There's a saying in the hobby here "nothing good happens fast" - let's slow down and take this one thing at a time:

1 ) I'm not too familiar with Jungle Start, but if you're using water from the actual ocean, there's shouldn't be a need to use something that removes chlorine.

2 ) To my knowledge, most additives that claim to heal fish and/or improve water quality do neither or only work in a very limited fashion - to my knowledge, they're typically quite literally useless for most aquariums (snake oil, scams, marketing - call it what you will, they're not products anyone typically needs).

3 ) To my knowledge, the only way to improve your critters' immune systems is by keeping them in the best health possible through good water quality and proper feeding.

4 ) The only bottles of bacteria for tank cycling that I'm aware of that are worth buying are FritzZyme TurboStart 900 Saltwater, Instant Ocean BIO-Spira, and Dr. Tim's Aquatics One & Only Live Nitrifying Bacteria for Saltwater Aquaria.

5 ) I'd personally pass on trying the chicken and beef, but if it refuses everything else, you can always give it a try. I'd also recommend leaving a camera recording the tank or something to see which creature (if any) eats the food, and to see if there are other issues that only show up when you're not there to watch the tank.

6 ) If the shrimp are just splitting to get out of their molt, then they're fine - if they're splitting and not molting but dying without a noticeable cause, the only things I can think of would be some sort of water quality issue or stress causing problems with their molting. Stress may be an issue if you have too many shrimp in the tank or if they're still in the tank with the crabs (I wouldn't try to keep more than one male and female pair of the shrimp in the tank - just one pair should be able to have enough room to live comfortably and without territorial aggression, which could be an issue with more than one pair). So, assuming you have the potential stress issues resolved, I'll address the water quality and molting issues again:

A ) Do you have test kits to test your water? I recommended Salifert or Redsea test kits for Ammonia, Nitrate, Phosphate, Calcium, Alkalinity, and pH in your other thread. If you have not been testing your water, I'd strongly suggest you start doing so, as this can help find a ton of different issues that might not be obvious otherwise.

B ) If your tank has been cycled, then you don't need to add more nitrifying bacteria (the bottle bacteria discussed above) to it, as it would have all the nitrifying bacteria it needs.

C ) If your tank has been cycled, then any ammonia tests you run should read 0 or within range of 0 when accounting for the test's error range (a lot of the time a test will inaccurately read 0.1-0.25 when there's actually no ammonia in the tank). If your tank has not been cycled, then add some of the bottle bacteria discussed above ASAP.

D ) Fast changes in parameters are usually bigger problems than parameters that are somewhat out of the recommended range, so most people - in an attempt to keep parameters mostly stables - recommend changing ~10% of the water in a tank each week (changing too much water at once can cause too big of a parameter change too quickly and lead to issues).

The range your parameters should be in:

Table 1. Parameters critical to control in reef aquaria.

Table 2. Other parameters in reef aquaria that aquarists may want to control.

7 ) I don't know why other people haven't commented.