Majority of snails not moving & some dying

[bitwise]

I've went through at least 20 snails (got killed or died off) in my Red Sea Reefer 170 over the last year or so. I also had a killer gorilla crab that I know for a fact was taking most if not all of these out.

Fast-forward to more recently: I took out the gorilla crab and I had 5 good size trochus snails (white shell) and 2 smaller banded trochus snails (purple striped shell). All 7 were happy and living just fine. After two weeks or so I could still count all 7 and I was happy about my choice to remove the gorilla crab.

Two weeks ago I had the light off on my tank on Monday - Friday except for at night when I was home, due to construction work (had a cover on the tank). There wasn't a lot of algae growth in the form of film algae on the glass during that time, but regardless I very rarely get film algae, I mostly get hair algae. There was still some short hair algae in various parts of the tank that looked consumable by the snails.

In the past week, I've had three snail deaths (two trochus and one banded trochus). The remaining three trochus snails have been in the same position on the glass for at least the last few days. I'm at a loss for what's going on.

Temps range from 78-80.5. I run carbon in a bag here and there. I have some poly filter which I've never used. Should I try that?

Please help!

[Subillbo]

I would suggest testing your nitrates..... inverts struggle with high nitrates, test and if high I would do some water changes. I had some die off a few weeks ago and it was because I changed my water change schedule and it affected my nitrates.... went back to what I was doing before and nitrates went back down.... snails r doing fine again. Hope that helps!

[Sk8r]

Hit the parameters in my sig line, as a set of numbers that will keep you out of trouble.

[bitwise]

My nitrates are usually < 2ppm, but I haven't tested in a while, I should test again.

[Sk8r]

Run the poly filter. It never hurts. As you say, they've been there long enough this shouldn't be happening. Sure all your tests are not expired? That gave me problems once.

[Michael Hoaster]

There are species of dinoflagellates that kill snails and fish, if eaten. Hopefully it's not that, but I wanted to point it out.

[Tripod1404]

What is your magnesium levels. High magnesium can make snails lethargic and even kill them.

Also how much algae do you have? For snails starvation can become an issue in most tanks.

[bitwise]

I had time to test a few params tonight:
Sg 1.026
Alk 8.8 dKH
Cal 420
Nitrate < 0.2 ppm

I still need to test mag. I'll add a photo of how much algae I have.

Theories so far that have to be explored:
- high mag
- starvation
- deadly dinos

What about temps? I routinely have temps as high as 80 - 80.5 F.

[Myers71]

Check to make sure nothing is leaching copper into your system. Speaking from noob experience brass s/o valves is a no no!


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[bitwise]

I had a crazy theory that the reason for the die off was me turning the light off for 5 days (circadian rhythm). So, I bought 11 more snails a couple of weeks ago, bringing the total to 14. I was away for about 10 days with someone taking care of the tank, and just got back yesterday. I came back to a tank that was covered in algae and I just pulled out 8 dead snails today.

I tested magnesium recently at ~1300 ppm. I really don't think starvation is an issue. I have copper pipes in my house, like most people do, but I use RODI water. There's no copper used in the system, though I've had a vortech fail here and there and have had some rust exposed to the water when this has happened.

Does anyone have any advice on where to go from here?

[Michael Hoaster]

Do you have any hermit crabs? They kill snails to get their shells. I'm of the opinion that you should keep one or the other - not both.

[bitwise]

I have one hermit, one bristle star, and one nassarius snail, which actually do a pretty good job at cleaning up snails when they die. I actually got rid of a bunch of hermits a couple of months back because I wanted to move towards just snails (to avoid them getting killed), but I missed one.

I bet my LFS has a copper test kit so I could go get that tested next weekend.

[monkeysee1]

.....what's your Ammonia level?

[bitwise]

I don't have an ammonia test kit at the moment. It's an established tank - over 2 years old - I'm confident it was at zero but I could see how loosing a few snails could make it detectable. I added a couple of capfuls of seachem prime to the tank yesterday to help out just in case.

One thing I found interesting: I cleaned the glass two days ago, which was covered in film algae and in a few spots hair algae, and seemingly within hours 3 more snails fell to the sand and appeared unable to right themselves. I just pulled two of those out (dead) and the third appears to be on it's way. I only have two snails that are alive. Maybe I do have deadly dinos and me cleaning the glass released them into the water?

[D-Nak]

Do you use an ATO? How do you keep your salinity stable? IME snails don't like a rapid shift in salinity.

[Rich1Reef]

Re-check salinity. I don't know what you are using to test it but I would recalibrate and check again.

When salinity creeps up snails will be the first to go.

[bitwise]

I use a Milwaukee digital refractometer, which I just cross-checked with a hydrometer. Both show sg of 1.026.

[bitwise]

I'm still planning on getting my water tested for copper at my LFS this weekend. At this point I think it's heavy metal or pollutant in the water, or something biological in the water. I'm running poly filter passively next to my filter sock, and have been since before this latest die off of 10+ snails.

[bitwise]

Also could be ammonia related, but I doubt it. I should get a test kit though.

[bitwise]

Do you use an ATO? How do you keep your salinity stable? IME snails don't like a rapid shift in salinity.

I use an ATO, which is dialed in. The only things that really mess with the salinity are me turning on/off the skimmer or the overflow drain box filling/draining due to the drain loosing it's tuning, but that's at a max ~1/2 gallon of water being added or removed (system has about 35 gallons total). This would be the same for virtually all RedSea reefer owners.

[D-Nak]

I use an ATO, which is dialed in. The only things that really mess with the salinity are me turning on/off the skimmer or the overflow drain box filling/draining due to the drain loosing it's tuning, but that's at a max ~1/2 gallon of water being added or removed (system has about 35 gallons total). This would be the same for virtually all RedSea reefer owners.

Doesn't sound like a salinity issue.

Not sure if you want to spend the money, but maybe an ICP test will show something?

[bitwise]

Not sure if you want to spend the money, but maybe an ICP test will show something?

I'm going to try a couple of more things, then probably going to go that route - good call.

[D-Nak]

I'm going to try a couple of more things, then probably going to go that route - good call.

Yah, even though it feels expensive, it's probably worth it. It's the price of about 20 snails so it makes sense to do it.

[bitwise]

I ordered a couple of ICP tests that I should have soon. It's my first time doing this. I went with a US based company and was able to get the tests for about $35 a pop (factoring in shipping) - not too bad.

[bitwise]

I finally did the ICP test and got my results back today. For those that are interested, I could use a hand interpreting the results.

[bitwise]

I found a helpful resource for interpretation online by Randy. Clearly my salinity is on the low side, and that's consistent with my most recent test of 1.024 sg. Also, magnesium is low. I'll address those asap.

I haven't found anything yet that would cause snail deaths though.

[boxfishpooalot]

Any dinoflagellets algae?

[five.five-six]

Sounds like dino’s At First blush.

[Oldreeferman]

So the 16938 ppm chlorine isn't an issue for anything then? That is all i see that caught my eye, but i use distilled water in my salt mixes & my top offs so no chance ever of adding chlorine or anything else actually and all my snails are still alive & actually breeding babys like mad after 2 yrs. with a temp at 78 in both tanks. Just wondering what lvl of chlorine...... might effect them is all....... if any. Its the one thing i have absolutely no concentration of ever is why im asking & id like to know if its an issue at any lvl for inverts since it isn't being mentioned only dinos etc.... just curious if its a factor at all dependant on ppm.