Snail die off

[monfilsi]

Hi!

All of my Banded Trochus Snail seem to be suffering from paralysis. They have all fallen off the glass to the floor. Their foot shows that they are alive, but they seem to lack the enegy to attach back to glass and just lie there slowly diying/starving.
I have pulled them all out of the tank and put them into my quarantine tank with some fresh aquaforest salt 24hours ago and they are still unresponsive.

The die off seems to coincide with my switch to Aquaforest Hybrid pro-salt for water changes. I have been dealing with some cyanobacteria for about 4-5 weeks (likely due to letting my phosphate creep up to 0.16ppm for a few months). It was suggested to me that I use the "Aquaforest Hybrid pro salt" to try to rebalance the healthy bacteria to fight off the cyano. I had done about 15% water change over 4 days before I noticed all the snails drop and have switched back to my regular aquaforest salt.
My 400L (105USGallons) tank is 1yr old. Mixed tank with mainly LPS and just started adding some SPS and have fish in there too with some shrimps and startfish . Dose All-for-reef, have skimmer, GFO and carbon filter. I do 10% water change per week gradually with automated water changer. Pictures of tank below. Picture taken early in morning so some corals are still opening up.
My Levels:
ALK: 9.5 kdH
Salinity: 1.025
PH: 8.0
Nitrate: 1.6ppm
Phosphate: 0.03ppm -> this was 0.12-0.16 until I started using GFO 7 days ago
Calcium: 450 ppm
Magnesium: 1700pm* see comment below: I don't trust this measurement
Amonia: 0ppm -> mesured off a cheap API test kit so take this with a grain of salt.

I have read that very high magnesium can paralyse snails. But I'm very sceptical of my magnesium reading. When I test the magnesium level of freshly mixed aquaforest salt I get 1800ppm with my red sea test kit (label says it should be ~1330pm). The Hybrid pro was measuring 1750ppm. I measured the magnesium 3 times for each salt mix and my tank and obtained consistent results. So I don't think the test kit is correct. Can't get the hanna magnesium tester where I live... at least not quickly and no reagent in country anyways.

Anyone seen any issues with their snails with cyano or any other ideas what could be happening? Coral seem ok, but alkalinity consumption seems less than usual so there might be some stress that I haven't identified. Need help to troubleshoot.

Thanks so much community!

 

[c4haskett]

I would definitely point back to your magnesium. Get another test kit and verify.

 

[Uncle99]

Mag.
Trust the test
1700ppm will slow/kill them

 

[monfilsi]

@Uncle99 @c4haskett. Thanks for quick reponses! I'll track down another test kit to confirm.

Lets assume that the magnesium result is reliable for the time being... then how can I drop it when the fresh water change salt is reading 1700-1800ppm at SG of 1.025? Any binders out there that force the magnesium to precipitate?

I can change salt brands, but to be honest I'm very surprised that two different bags of salt (albeit from same company) would have reading so far off from the manufacturing label of ~1330pmm. I'm also trying not to change too many variables at once as I don't want to crash the tank.

One thing that occured to me was that maybe salinity meter was off and I'm adding to much salt. Checked its calibration with calibration samples and it is right on.

 

[c4haskett]

@Uncle99 @c4haskett. Thanks for quick reponses! I'll track down another test kit to confirm.

Lets assume that the magnesium result is reliable for the time being... then how can I drop it when the fresh water change salt is reading 1700-1800ppm at SG of 1.025? Any binders out there that force the magnesium to precipitate?

I can change salt brands, but to be honest I'm very surprised that two different bags of salt (albeit from same company) would have reading so far off from the manufacturing label of ~1330pmm. I'm also trying not to change too many variables at once as I don't want to crash the tank.

One thing that occured to me was that maybe salinity meter was off and I'm adding to much salt. Checked its calibration with calibration samples and it is right on.

I'm not sure of any binders. Are there any other parameters besides Mag that are reading high in newly mixed salt? The only thing I know to do is use a salt with low mag and slowly bring it down. What I've noticed (using reef crystals) is that if I mix my salt too high ( I eyeball mine) and drain some out, and fill with fresh RODI is that even though I diluted the salt mix the parameters are usually higher than mixing it spot on the first time.

 

[monfilsi]

UPDATE:
I got another test kit that included a reference sample with a mag concentration of 1310pmm+/- 1%, so anywhere from 1297 to 1323. The reference measured 1400 on my red sea kit. So when I measure 1700pmm on my red sea kit, the real value around 1610. So my magnesium is too high and has been for 3+ months. My plan is to change salt with a lower magnesium. I picked up some tropic marin pro-reef and it is measuring ~1330ppm. I will slowly start to do water changes over the next 2-3 weeks to bring the magnesium down.

Snails have been sitting in the tropic marin water for 24hours... don't think they are going to make it.

 

[Doctorgori]

Upside down with foot curly and partially sticking out, foot is firm but it won’t close up?

This has happened to me a few times (all snails paralyzed and/or upside down)////No clue why but I suspect it was peroxide dosing (in my case) …

Take them out immediately, place in clean water with a powerhead (or airstone) ….you can use a 5gal storage container , don’t bother feeding, if closed up, press the opening with your finger; if it gives, chuck the snail…if firm, its still alive
Most of mine made it…I JUST did this a couple of week ago

 

[c4haskett]

UPDATE:
I got another test kit that included a reference sample with a mag concentration of 1310pmm+/- 1%, so anywhere from 1297 to 1323. The reference measured 1400 on my red sea kit. So when I measure 1700pmm on my red sea kit, the real value around 1610. So my magnesium is too high and has been for 3+ months. My plan is to change salt with a lower magnesium. I picked up some tropic marin pro-reef and it is measuring ~1330ppm. I will slowly start to do water changes over the next 2-3 weeks to bring the magnesium down.

Snails have been sitting in the tropic marin water for 24hours... don't think they are going to make it.

Thanks for the update and glad you got it figured out.

 

[monfilsi]

Upside down with foot curly and partially sticking out, foot is firm but it won’t close up?

This has happened to me a few times (all snails paralyzed and/or upside down)////No clue why but I suspect it was peroxide dosing (in my case) …

Take them out immediately, place in clean water with a powerhead (or airstone) ….you can use a 5gal storage container , don’t bother feeding, if closed up, press the opening with your finger; if it gives, chuck the snail…if firm, its still alive
Most of mine made it…I JUST did this a couple of week ago

Thanks for the tip @Doctorgori. Will sort through them today. I have them in a quarantine tank.

 

[Doctorgori]

I forget what that door thing is called (operculum)? erh sumthin like that …if that thing is dead, it will push in and stink…if firm, the snail is probably still alive, give it a day or so

 

[monfilsi]

[Another Update]

I have been bringing my Magnesium levels down from ~1700ppm over the past 25 days with 8% water changes per day. Also stopped dosing any Mag by making my own own "all-for-reef" without the mag (https://www.reef2reef.com/threads/diy-all-for-reef-recipe-from-tropic-marin-thanks-zack.659055/)

Lost all the snails. Wasn't able to save any in quarantine tank with Tropic Marine salt. Everything else in the tank seems to be doing ok. Good thing I didn't have any clams.

Some additional learning for me: I found that aerating my salt water mix give me more reliable test results on parameters.

Now that I'm back around 1400ppm I will pick up some snails and introduce to the tank.

Thanks to all for your assistance through the journey.

 

[monfilsi]

Magnesium is now stable down to 1450ppm. Still a little higher than I would like and still not dosing magnesium.

I stocked the tank with another 10 trochus snails 3 weeks ago.... I have 1 snail left. FYI I slowly acclimitized them to the tank water before introducing to the tank. They have been slowly dying off at the rate of 1 every 3days. Only real trend that I observed is that if they touch the sand they die within a day or so. Even If I put them back on the glass they are dead by the next day.

Salinity: 1.026 SG
PH: 8.03
Amonia: 0.006 ppm
Nitrate: 2.1 ppm
Phosphate: 0.1 ppm
Alkalinty: 9.3 kH
Calcium: 450 ppm
Magnesium: 1450 ppm

I suspect that there is a pathogene that is killing them off. I do have mild case of cyanobacteria that I have been battling for 7weeks or so. Seem to be slowly getting better. I couldn't find threads about snails issues with cyanobacteria. Found a a number of dinoflagellates that can kill of snails.

All other wild life seem to be fine. I do have a couple hammers that are not opening up as usual recently. Have moved them to a lower flow area in the tank to see if they open up.

I guess the next steps is that I need to get my hands on a microscope to conclusively identify the cyano. And I'll do an ICP test to see what I'm missing.

 

[monfilsi]

ICP test had everything within normal parameters and no heavy metals or undesired chemicals.

BUT microscope confirms that I have dinos... so they must be toxic to my snails.

So now I need to figure out how to get rid of them. Let the research begin.

 

[slingfox]

Try adding a snail type (or two) other than Trocus. Fragbox Corals has an older video on cleanup crew and they stated that they stopped using the more typical Banded Trocus in their systems since they die most easily. They instead use Spiney Trocus which are hardier. I also recently had a CUC die off due to an equipment failure. When I restocked I put in 3 large Astria snails to make sure conditions are stable. I will eventually add Trocus later.