Help with algae or bacteria identification that grows on rock and may kill snails

[AlexLS]

Hello,

A few months ago on a 6 month old tank I had an issue of snails that die for unknow reasons. (no fish, crabs or predators)
They just become slower and slower until they won't able to hold on to anything and just die.
At that time I had something like this on the rocks:

After some time my Po4 went down and No3 stayed normal and... short story... cyano. Lots of it, covering everything. (cyano confirmed with microscope)
During this time tank looked like crap but no snails died.
After months of fighting trying every method possible. Unable to get nutrients up, killing corals despite all attempts I used erythromycin a few weeks ago.
Worked like a charm, some small dino patches here and there but got solved naturally fast as I kept a hawk eye on tank parameters to avoid swings. Tank is now 1 year old...so yea ,about 5 months of fighting cyano. (I got enough of it)
Today, No3 is around 3-4 and Po4 around 0.05.

Trouble is, that the stuff above appeared again and of course, snails begin to die again.
This is under microscope:

What is this? Is this killing snails? How do I get rid of it?

Thank you in advance.

 

[taricha]

aaagh.
This is chrysophytes, but I do not think we have had reports of it killing snails before. However your snail behavior (increasing lethargy, eventually death) is very much how algae toxins would be expected to behave.

 

[AlexLS]

Yes, comparing google results with what I have, indeed looks like it is some sort of chrysophytes. Strangely they don't seem to be toxic. So I wonder what's up with snails. Anyway, thanks for info, now I need to figure out how to deal with this.

 

[Udest]

thats wierd i had the same thing happen to a Mexican turbo a while ago did they constantly retract into their shells like they were having a seizure?

 

[RustyBuckets]

They just become slower and slower until they won't able to hold on to anything and just die.

I'm having the exact same problem. Every single snail I get starts off eating well, slows down, and dies within a week. I'm battling a hair algea outbreak. Added GFO, carbon, and a plenty of bacteria to get parameters back to normal reef tank ranges, but still cant keep my snails alive. Peppermint shrimp, emerald crab, and tail spot blenny seem to be doing ok, so I'm at a complete loss as to what's up with the snails. Did you ever get you problem resolved?

 

[Jubei2006]

I would look at the type of snails being used. Udest stated his mexican turbos did that. Well they are a colder water snail and don't appreciate our 80 degree reef tanks. So even though a lot of different species are sold, I'd do some quick snail research and see if it doesn't change your mind. Trochus are the larger species I look for. Nassarius and ceriths for the sand bed. Astreas are good, but cant right themselves if tipped over. And don't forget, hermits will kill them for their shells.

 

[RustyBuckets]

I would look at the type of snails being used. Udest stated his mexican turbos did that. Well they are a colder water snail and don't appreciate our 80 degree reef tanks. So even though a lot of different species are sold, I'd do some quick snail research and see if it doesn't change your mind. Trochus are the larger species I look for. Nassarius and ceriths for the sand bed. Astreas are good, but cant right themselves if tipped over. And don't forget, hermits will kill them for their shells.

Thanks for the feedback. I've tried all those snails you mentioned, except for nassarius since my substrate is crushed coral. The only ones that dont seem to slow down and die are the ceriths who seem to stick to the substrate or occasionally the glass. Yeah, the few hermits I have do harras them at times, but I have losts of empty shells for them and dont see them bothering the other snails.

My tank tends to sit arround 77F. I've had it for about 5 years and didnt have issues keeping Mexican Turbos or Trochus until my algae bloom in August.

I think one of the big turbos got stuck and dies in the back of the tank and started a chain reaction. Had high ammonia, high phos, low kH, low Ca, low nitrates. The tank was a mess!

After much effort all perams are good now, but there's still some algae everywhere since everything was covered. Since the growth is under control now I was hoping the snails could clean up what I cant scrub off. Like I said, the do good at first, then take a nap and die.

I'm starting to think it must be the algae, since all other measurable parameters are now under control. But, if I've got some kind of toxic algae, what the heck can I do?!

The observable alge is green film, green hair, and purple coralline algae. There's also some long white filament stuff that grows in the dark places (nothing eats it). Hermits ate what little bubble alge I had and now I have to feed them seaveg and chato from the sump.

Short of moving my blenny to a holding tank and bombing the system with pods, I dont know what to do....

 

[Jubei2006]

Also just a thought, what are your magnesium levels at? Also think about iron. They use various forms of iron in terrestrial slug/snail killers. Also have ready several times over the years that magnesium levels too high can kill snails.