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Alarmguy66
10/10/2006, 09:30 AM
Problem - for the last month my snails have been dying. Probably 50% in the first week, the rest (mostly the larger ones) dying off slowly after that.

ph - 8.2
alk - med to high (no exact #)
temp 82-83 (fan recently burned out raising temp from 81)
salinity - 1.024
tank age - 3 years +, 180 gal, 55 gal sump
water well water through ro/di
live rock - 250 lbs (all 2 years old or more)
4 inch sand bed
Only additive I ever use is Wages Lime in the top off water

What Ive noticed -

All this seemed to happen after I rid the sump of all caulerpa. I still have sea grass and cheato growing in the sump. Could be coincidental. Pods are still present.

I dont remember the timeframe, but recently stirred the sand bed in a few places and saw some darkened (almost black) sand come up. Covered those places back up.

Smallest snails (2-4mm), little guys that came on the Florida live rock seem unaffected.

Nassarius snails seem unaffected

Cerith, astrea, conch, turbo - dead

Starfish, all fine (maybe slightly less active?)

crabs, all fine

fish all fine

corals all fine

Clam - starting to not open quite as full

Ran phosphate remover for 7 days, performed 2 - 20 gallon water changes and a 40 gallon change over 3 weekend periods.

Randy Holmes-Farley
10/10/2006, 11:26 AM
Dinoflagellate toxin often afflicts snails before other organisms, so if you have dino's, that may be a concern.

Copper may also hit snails before other organisms, but shrimp are often up there too.

The hydrogen sulfide that may have been released with the black sand my poison lots of organisms, but I do not know if snails are more prone to concerns or not:

Hydrogen Sulfide and the Reef Aquarium
http://reefkeeping.com/issues/2005-12/rhf/index.php

Are you using tap water to make the limewater?

Alarmguy66
10/11/2006, 08:36 AM
I use my ro/di water for top offs. I saw plenty of those little tiny snails last night and one HUGE turbo that still hasnt kicked it. Everything else seems ok with the exception that now, with all those dead snails in the tank (the ones in the rockwork I cant get to) I'm getting some cyano outbreak.

bertoni
10/11/2006, 02:23 PM
Hmmm, interesting...

Do the smaller snails seem to be proliferating? They often seem to be able to starve out their larger cousins. Is there an upward trend in microalgal coverage?

Have you ever verified the accuracy of the SG device?

Jonnyacrofeed
10/11/2006, 03:28 PM
Could it maybe be that the temp. is too high?

Alarmguy66
10/12/2006, 05:39 AM
The smaller snails come out en masse at dark, and theres a lot of them. The crabs seem to be doing ok, but they could be feeding on the dead snails too.

Now the clam, I hadnt thought about this...He didnt start closing a bit until I move him up about 6" closer to the lights...he might just be acclimating to the new light. Probably nothing much to worry about there.

Temp - yeah, I need to get me a new fan. I robbed the last one out of an old pc power supply but salt creep got it. Already figured out how to stop that from happening next time. It never gets to 84, so Im thinking its ok.

Refractometer is used for sg readings, dont know how to verify its right.

Driftwood
10/12/2006, 07:51 AM
Use RO/DI water to dial in your refractometer, it should have a small screw to adjust it.

bertoni
10/12/2006, 12:11 PM
http://www.reefkeeping.com/issues/2004-06/rhf/index.php

That article might be useful.