Progress updates

[Varanus]

Well here's a mystery. I was gone for a few days and when I return I find that the mossball in the tank has vanished. I've looked at the tank from every angle and I can't find it or even fragments of it. My only guess as to what happened is that somehow for some reason a shrimp took and hid it somewhere inside the holey rock (even if the remaining snail/s wanted to eat I don't think there are enough of them to have actually devoured it so completely so quickly, plus they haven't touched it in all the time its been in there, I don't think they could/would bury it either). Strange...

Assuming it doesn't show up again it looks like I'll need to order another one or two.

[Varanus]

Lo and behold the moss ball reappeared! It seems to be growing and/or getting more air stuck in it, and thus is really easy for the shrimp to move around. I tried squeezing it a bit to lessen this.

Anyone have a good way of telling the difference between moss ball fragments and fragments of the macro algae? I've been removing bits that I thought were bits of macroalgae that got transferred to the new tank by accident, but now I am wondering if they were actually the start of new moss balls (though they looked nothing like moss balls at the time).

On another note, tons of larva and baby shrimp, I counted at least 70 (all those specks floating around in the picture). The shrimp seem eager to fill up the new space, and they still have no shortage of algae.

[Mustafa]

About 30 shrimp larvae bobbing about now brings the population to 190 assuming they all survive to metamorphose. All else routine, including the surviving snail seeming to be fine.

That's good news! So the shrimp and snail are feeling happy again. As for the snail...it will have to be the "founding mother" of your new snail colony. Glad things are continuing to go well for you.

[Mustafa]

Lo and behold the moss ball reappeared! ....

Anyone have a good way of telling the difference between moss ball fragments and fragments of the macro algae?

I figured it would show up! In all these years I have never seen a mossball just disappear or even disintegrate. As for how to tell the fragments apart...mossballs literally bud tiny fuzzy pieces that you can't even see (most of the time). Macro pieces should be more elongated. Either way, it doesn't hurt to let the fragments grow a bit to see what they turn into. Given how slowly the mossballs grow and "take over" the tank you don't want to inadvertently throw away any possible mini-balls.

[Varanus]

Well, continuing the saga of the bizarre snail-killing tank, the survivor eventually ceased appearing and is presumed dead. I went ahead and ordered more snails from Mustafa a couple weeks ago and at first all seemed fine. Snails would come out at night and sometimes other times of day, graze on surface film, etc. But over the course of a week I started seeing bad signs, namely snails sitting on the sand, hanging out of their shells or producing a lot of excess slime (classic signs of snails that aren't feeling well). Observed activity decreased more and more, and its been days now since I've seen any snails moving.

I can only surmise that this batch is doomed too. And I am still no closer to figuring out what could be the cause. What could be killing these adaptable snails and yet bring no harm to my shrimp? The shrimp continue to reproduce happily, and the mossball has even reproduced.

The closest thing I have to a theory is that there is some kind of toxin in/under the substrate (albeit its the same brand of inert sand I use in another tank where the snails are fine), a toxin that got there back when I first set up the tank as a freshwater tank and has remained, eventually killing every snail I have put in the tank despite the many routine water changes I did back then over the years for maintenance. Barring that, I can only think that the aquarium itself had some kind of toxin on its floor when I brought it.

A part of me would like to test the theory by replacing the substrate. However, with hundreds of shrimp and many larvae in the tank I would prefer to not stress them out, not to mention the potential danger of losing the bacteria in the substrate if it isn't the cause of the snail problem.

So unless there is a good way to figure out what it really wrong, or the shrimp themselves start to act sick (unlikely as they've been in the new tank for months now without issue), I guess I may have to settle for this being a shrimp only tank.

Don't get me wrong, the shrimp are the main point of the tank. I just liked having a bit of variety, plus creatures better able to handle cleaning the tank glass.

[Super Jess]

Sorry to hear about your snail mystery. Could you scoop out a bit of the substrate and put it into a clean vessel with fresh snails to test the toxic substrate theory? I agree it seems a shame to disrupt the entire tank if everyone else is doing fine.

[Varanus]

I could try that, but there's no guarantee what I scoop out would include whatever substance is causing the problem. I just can't imagine either what could have stayed in the tank for so long without breaking down or getting sucked out or simply getting diluted until it was harmless.

[Super Jess]

That's true. Such a strange problem! I would expect the shrimp to be the bellwether, not the snails. I hope Mustafa has an idea about it.

[Mustafa]

Hmmmm....so when this tank was a freshwater tank all the snail you put in also died despite regular water changes? If so, then maybe there *is* something in your substrate/decoration that's affecting just them (and not the shrimp).

Did you ever do the 80-90% water change I recommended a few months ago? If your freshwater tank supported snails at some point (which would mean the substrate was fine and water changes took care of whatever was in the water), then the water change should solve the problem. If not...well, if you wait long enough whatever the culprit is will eventually get absorbed by biofilm and other plants and your tank will support snails again. I know you don't want macroalgae, but that is probably the quickest way to export what's in your water unless you do decide to do a water change.

I doubt there's something leaching from the tank itself so we can probably safely exclude that as a culprit.

[Mustafa]

Congrats on the "baby" mossball by the way!

[Varanus]

Hmmmm....so when this tank was a freshwater tank all the snail you put in also died despite regular water changes? If so, then maybe there *is* something in your substrate/decoration that's affecting just them (and not the shrimp).

Seems possible, as far back as I can remember regarding this tank it killed snails. It wouldn't be a decoration at least (or I don't think so), as they've all changed over the years.

I think I first noticed when I transferred over a population of assassin snails (I wanted to use the tank they were in to breed some rabbit snails), and was surprised to see them die off rapidly as they'd been doing so well in their original tank. Over its life time as a freshwater tank I saw the same thing happen to nerite, mystery, trapdoor and even malaysian trumpet snails I tried to put in it (with the trumpet snails I experimented by splitting the group I got and putting half in one tank of the same size, upkeep and type of substrate and half in the snail killing tank, the descendants of the ones in the former tank are still around, the ones in the latter long gone).

Did you ever do the 80-90% water change I recommended a few months ago? If your freshwater tank supported snails at some point (which would mean the substrate was fine and water changes took care of whatever was in the water), then the water change should solve the problem. If not...well, if you wait long enough whatever the culprit is will eventually get absorbed by biofilm and other plants and your tank will support snails again. I know you don't want macroalgae, but that is probably the quickest way to export what's in your water unless you do decide to do a water change.

I think it was closer to 60% but yes I emptied a lot of water when changing the tank to a brackish water tank. Looking back it would have been a good time to replace the substrate, but I was so sure that the big water change and change to brackish water would be enough to remove the snail killing curse.

Since my earlier post I've seen a snail or two moving about on occasion, so maybe the tank is getting better or they're adapting.

[Varanus]

Well the good news is I counted five snails active yesterday. I'll know for sure they've conquered the snail-killing tank if I see some babies, but haven't yet.

In other news, I have a question about this stuff growing in the tank. When they first showed up they looked roughly spherical so I assumed they could be baby moss balls, but as they've grown I've started to doubt that assessment, so it seems my moss ball may not have reproduced after all. They've long stopped looking spherical. Like Mustafa's macroalgae they don't really cling to anything and just grow as clumps of threads, yet they also are thinner than Mustafa's macroalgae. Nothing like it was in the tank during its freshwater days either so I am at a loss as to where it came from if its not macroalgae or a moss ball.

Hopefully the picture is good enough to give you guys some idea of what this algae is, I couldn't get it to focus up close.

[Mustafa]

I'm pretty sure your snails will be fine from now on. As for the mystery plant...it looks like it's hair algae, just not the type that attaches itself to things. The spores could have come from anywhere. Can you take a picture from the side?

[Varanus]

I'm pretty sure your snails will be fine from now on. As for the mystery plant...it looks like it's hair algae, just not the type that attaches itself to things. The spores could have come from anywhere. Can you take a picture from the side?

Pictures from the side would actually be less clear thanks to the algae on the glass. No worries though, I went ahead and removed the clumps. Guess the moss balls really do reproduce slowly.

[Mustafa]

I see. Yes, the mossballs reproduce slowly...*but* once they get going your entire bottom (or a significant part of it) is suddenly filled with tiny balls that you simply didn't notice before. If you want to accelerate it, you can try to feed more. Mossballs are plants after all and don't mind the fertilizer.