On the verge of a crash?

[MJAnderson]

I'm having some tank issues. First the setup

72g bowfront
29g sump
ASM g3 skimmer
Fish:
1 4" Kole Tang
1 3" coral beauty
2 2" Perc Clowns
1 2.5 Lawnmower blennie
1 small 6 line wrass
1 3" dottyback
2 2.5" Chromies

OK, my sad story. About a month ago I bought a bad batch of 20 snails. All died within a few days of putting them in my tank. Other snails started to die off (I didn't know it was just the new ones since they were the same kind) and I lost probably 40 snails in the last 4 weeks. Last week my frogspawn and one of my corals started looking a little unhappy. I tested all my parms (usually just Calc, alk and mag) and found that my nitrates were around 2.5-5and amonia registered, although below even the first mark. They had never registered before.

Anyway, my snails keep dieing, my corals continue to look unhappy (especially the 2 pociliporas and the frogspawn) but the fish look fine and other corals are colored up and growing.

Any thoughts? Besides stepping up the water changes (did 2 20% weekly changes instead of my usual 10%) should I be looking into something? Is my bioload too large or did the snail massacre a month ago start a cycle that my system can't handle? I haven't added any new fish in a while but they are getting bigger.

Thoughts? Things to look for?

 

[Steven Pro]

Put a Polyfilter into the system somewhere and look for any odd color changes.

 

[stevestank]

problems

problems

Wow... sorry to hear about your carnage. I'm guessing you have plenty of live rock, plenty of flow, light, etc... I might be able to come over to take a look. I went to a friends house and ran about 12 tests. I found quite a few issues that don't seem like a big deal. However, when you consider all of them, it can start the dreaded downward spiral. I have 13 fish in my 125. However, the largest is a yellow tang. Sometimes I think I have too much bio load. I'm certainly at capacity. Bio load might be an issue. Flow might be a player and your dissolved Oxygen leves may be low.

 

[serpentman]

I hate to say it but it sounds to me like its bioload related. Basically your biological filtration struggles to keep up and then starts to fall behind. A simple event like the death of a few snails could have put it over the top. 40 snails could definitely trigger another cycle. I would run the polyfilter just in case to make sure there are no heavy metals present. Although your skimmer should be more than sufficient, maximizing its efficiency will also help.