Deresa Clam growth slowing?

i cant think · Mar 14, 2023

Hey there reefers!
I have a predicament;
I have had my Deresa clam in my 3’ SPS nano for 6 months now (It was in my previous nano for 5 months) and it’s thrived previously. It had a huge band of pure white growth when my dKh was up at 12. It’s now balanced itself back to 9/10.
I have 2 clams in this system;
A 4” (ish) long deresa and a 2” long Maxima.
My maxima is thriving under 375-400 (possibly now 450) PAR. My Deresa is on my sandbed getting around 300-350PAR.
As seen in the photo below, my Maxima has a beautiful band of white and is growing its second row of scutes in its time with me (4-5 months).

Now, my deresa on the other hand. As I said, it had a white band of growth (seen in the photo below). But now it has almost no white growth visible that isn’t hidden under the mantle. Tonight when lights go off I’ll get a better photo of under the mantle and that white growth however as seen in the last photo, it has just a small strip of white growth. I will get a test of my parameters tomorrow in my spare time.
Growth from only 1 month ago;

Todays growth;

i cant think · Mar 15, 2023

Bump.
Here’s the photo with a more retracted mantle.

@OrionN any ideas?

wjgeese · Mar 15, 2023

What does your water chemistry look like? ca, alk, mg, pH, phosphate? Any of these factors alone or in combination can impact clam growth if not within normal parameters and are stable. Wild swings cam be stressful as well. any pests in the tank (fish, pyramid snails, crabs, shrimp?).

OrionN · Mar 15, 2023

How big is your Nano?
Sometime when we overpopulate clams in our system, they run out of micronutrients. I am not talking about nitrates and phosphates, but micro-nutrients and trace elements. When this happened some of the clams seem to not doing well while others seem to be fine. Normally, the larger ones would be the last to be affect and smaller ones would be in trouble first.
I would do water change, if you are not doing this already, to replenish the nutrients and consider add trace elements into your tank. What elements they need I am not sure; I keep clams for a long time in various size tanks from 20 to 420 gals. I keep 30+ clams in my 420 and start to run into problem with similar to you and this improved when I removed some of the clams and increase my water changes. I did not have to add trace element. I use corals and clamshells-based calcium reactor to supply my calcium at the time.
Good luck with your clams.

wjgeese · Mar 15, 2023

strongly suggest you perform an icp test before you start adding trace elements. It's good practice to test for what you dose. ICP testing is a good way to keep an eye on the elements that your typical home test cannot monitor.

i cant think · Mar 16, 2023

OrionN said:
How big is your Nano?
Sometime when we overpopulate clams in our system, they run out of micronutrients. I am not talking about nitrates and phosphates, but micro-nutrients and trace elements. When this happened some of the clams seem to not doing well while others seem to be fine. Normally, the larger ones would be the last to be affect and smaller ones would be in trouble first.
I would do water change, if you are not doing this already, to replenish the nutrients and consider add trace elements into your tank. What elements they need I am not sure; I keep clams for a long time in various size tanks from 20 to 420 gals. I keep 30+ clams in my 420 and start to run into problem with similar to you and this improved when I removed some of the clams and increase my water changes. I did not have to add trace element. I use corals and clamshells-based calcium reactor to supply my calcium at the time.
Good luck with your clams.

My nano is a 25G tank (90L). I do a weekly water change every weekend.
One thing I did have to do was move the clam a bit further back during the water change a few weeks ago as it was touching the glass and had a small area to grow in. I also lowered my white percentage last weekend as I didn’t enjoy too white of a light (However to the eye you can still see how white it is).

wjgeese said:
What does your water chemistry look like? ca, alk, mg, pH, phosphate? Any of these factors alone or in combination can impact clam growth if not within normal parameters and are stable. Wild swings cam be stressful as well. any pests in the tank (fish, pyramid snails, crabs, shrimp?).

I have shrimp however none of them go for the clam (They’ve all been in the tank with the clams for months now). I’ve avoided crabs due to having a love for snails and pyramid snails are not in the tank either. Fish are minimal currently and none of them nip close to the clam.
As for my parameters, last time I checked I had;
Ca is 500ppm
Mg is 1360ppm
Kh is 10.40dKh
Po4 is 0.30mg/l
No3 is 0.3mg/l

I’ll do the tests again today and update with more accurate readings however generally my parameters aren’t swinging completely.

minus9 · Mar 17, 2023

How often are you feeding the tank/fish? Clams do need some nitrogen and they usually get that by the way of filtering water for food/particulates, i.e. fish food/poo.

i cant think · Mar 17, 2023

minus9 said:
How often are you feeding the tank/fish? Clams do need some nitrogen and they usually get that by the way of filtering water for food/particulates, i.e. fish food/poo.

I feed the tank once a day every day.

OrionN · Mar 17, 2023

What size are the two clams.
Never mind. I went back and read the 1st post. Again.

minus9 · Mar 17, 2023

i cant think said:
I feed the tank once a day every day.

I'm a huge fan of frequent feedings throughout the day, either by hand or auto feeder (or both). To some this sounds like a lot of food, but it's actually not that much. The one thing you accomplish by feeding throughout the day is having a constant supply of nitrogen for the tank as a whole. This is a plus in so many ways, but most people worry about nutrients causing more algae and forget that the same conditions algae require to grow are the very same conditions corals need to grow.
In short, feed more throughout the day, smaller amounts of course, but more.

MartinM · Apr 7, 2023

Feeding more is always a good thing as are white lights for clams but I wouldn’t worry too much as long as all parameters are in line and it is growing. If you’re not increasing your feeding as the total biomass in your aquarium increases, then growth of all of the organisms in your aquarium will inevitably slow down.

FWIW, I feed via automatic dosing at least four times a day, and by hand another 4 to 5 times per day and I still have low nutrient issues because growth increases in proportion to the feeding!

i cant think · Apr 7, 2023

MartinM said:
Feeding more is always a good thing as are white lights for clams but I wouldn’t worry too much as long as all parameters are in line and it is growing. If you’re not increasing your feeding as the total biomass in your aquarium increases, then growth of all of the organisms in your aquarium will inevitably slow down.

FWIW, I feed via automatic dosing at least four times a day, and by hand another 4 to 5 times per day and I still have low nutrient issues because growth increases in proportion to the feeding!

I’ll try increasing the feeding and see if the oils from foods help with growth

I’ll also get photos from today and see if there’s been any growth updates.

MartinM · Apr 7, 2023

IME phyto never hurts, it’s of course hugely plentiful in the ocean

i cant think · Apr 7, 2023

MartinM said:
IME phyto never hurts, it’s of course hugely plentiful in the ocean

I have been meaning to dose phyto for my Pods however didn’t get round to it before leaving to see family, hopefully when I get back the tank sitter has fed it however if not I’ll throw it in and try aim for the deresa.

MartinM · Apr 7, 2023

i cant think said:
I have been meaning to dose phyto for my Pods however didn’t get round to it before leaving to see family, hopefully when I get back the tank sitter has fed it however if not I’ll throw it in and try aim for the deresa.

Careful about target feeding, just dose the tank and it’ll filter it out

minus9 · Apr 7, 2023

I dose EasyBooster by Easy Reefs, it's an awesome "whole" tank food/phyto. I also dose their SpsEvo. The great thing about both is, you don't need to mix/shake/stir or refrigerate, just hook up to your favorite doser and go. I've been using their products for a few years with great results.

OrionN · Apr 7, 2023

How are the rest of your hard corasl growth? Is it too much phosphate or too low pH, both of which can inhibit calcification and promote non calcaneus algae?
I normally do not worry about too little nutrient in my tank, rather I worry about too much. I tend to over feed my tank rather than under feed.
I guess my fish almost always have as much food as they can eat so too little nutrient is not a problem I run into.