In need of a reef detective


Why do my snails die? I'm on my 2nd batch of astrea snails in a month, the first 10 died in a week, and already 2 have died from the 2nd batch added lastnight.
Heres the tank:
75gal used acrylic SeaClear System II tank with built in overflow wet/dry filled with LR rubble and cheato, built in skimmer. (This tank was used for many things (reef, reptile, Koi) by it's previous owner who took a natural approach at petkeeping. Possible copper poisoning here, but does acrylic absorb copper?
100lbs of 6yr old LR in beautiful condition from a board member (thanks again kpatrick)
1" - 2" CaribSea argonite with 20lbs of CaribSea LS
12 X's water flow thru 4 PHs / pumps
260W PC's
1 Chromis
1 Cherub
1 Yellow Tang (spare me the details)
1 Cleaner Shrimp
1 Coral Banded
1 Peppermint
1 Emerald
15 Scarlets
6 Blue Legs
13 Astrea
1 Sandsifting Star
Tank is in it's 5th week, I started it with tapwater and am using RO for top-off water. I have lost 8 fish, 5 chromis from a nasty (***** 3/$3) internal parasite that exploded from the inside (the 6th one is doing great for weeks now), 2 curious cleaner gobies to a non-screened powerhead (poor things) and 1 two spot hogfish who jumped to his freedom and found the carpet. In 7yrs at this hobby I've never lost this many fish. 3 remaining fish are fat and happy and protected from the hungry powerheads. All inverts are doing great, multiple molts, so I am doubting copper poisoning, but am waiting for my testkit to arrive. The LR had 2 colonies of green Star Polyps on them which were doing great for 2wks, now should be considered dead after the first addition of RO water / slight salinity adjustment in week 3. I have since dropped the salinity back to the original point after remembering SG changes with temp
. I just finished the diatom phase and are moving into the green peach fuzz on the glass phase, so things are progressing nicely. Right now, the RO water is my #1 suspect since it came from a machine at the water peoples building, but I can't find a LFS who has an TDS meter to test it. Thanks for taking the time to read thru this mess and please don't assume I'm a noob, look at my join date, but if you see something obvious, please post it. I'll leave you with my water specs which have not changed since week 2.
Temp 80 - 82 (this bothers me and is suspect #2)
Ammonia - 0
Nitrite - 0
Nitrate - never over 5
PH - 7.8 or 8.4 (stupid color-blind testkit)
SG 1.023 at 82deg (waiting for my refracto)

nemo's mom

too much bioload too fast!! A saltwater tank needs time to adjust to a new bioload. If your tank has been established for 5 weeks, it's barely done cycling. You should have added about 1 fish per month....I'm sure you'll get a more educated response from someone else but I'm pretty sure that's at least part of the reason....


it could be copper poisoning, but then the other inverts would die, i suspect a predator in the tank i have seen emerald crabs eat my snail in the past its probably them eating or killing your snails.


My tank cycled in 24hrs after adding the rock on day 3, but I know what you're saying on the load, just because it cycled, didn't mean it was matured. Anyways, it was just the Cherub, Hog and 2 cleaner gobies before they met the hungry PH, then replaced them with 3 chromis, 1 died that night so I went to replace him and brought 3 more home, so I was at 1 Cherub, 5 Chromis and the Hog at the beginning of week 3. I lost 1 Chromis a day, first you would see a line in their scales which reflected differently, then a bulge, then open wound or death. During this time, the Hog jumped. So the bio wasn't huge, all the fish described never inhabited the tank at the same time and the LR was used to much more than that load. The water levels never registered the load either.
I know it's not predation since they just fall to the bottom and rot. The Emerald (with monster claws :scared: ) has only been in the tank 24hrs.
Copper is still on my list in 3rd place since I'm sure snails are more sensitive to trace levels of poison and I know star polyps are sensitive to change. The few mushrooms scattered in the rock are alive, but not what I would consider thriving, prolly 1/3rd open. All corals showed negative signs after the first addition of RO water in week 3, snails began dropping around the same time too. I also raised the the SG to 1.024 with this top-off and then lowered it back down to 1.023 the next afternoon. The Star Polyps fought it for a week and have been completely closed for 2weeks, so I know the change in SG was not the ultimate enemy since they've had 3wks to adjust now.
Thanks for the replies, I wish it were that simple.