I need you fish friends!

[fulltimemom]

I still consider myself a rookie after having a 30 gallon saltwater tank for 2 1/2 years. I rely on the fish store which is full of knowledge but our tank has completely stumped them recently. I have learned a ton through all of you over the past couple of years and now I desperately need help and advice. I will try to summarize but seriously grab a beverage:

Tank has been beautiful for 2 years 3 months. 3 months ago I changed out both bulbs same time (rookie) and had an algae bloom. Got that under control by adding 5 snails, they went to town, then corals started to not look great. Started with the advice from fish store weekly water changes 6-8 gallons. Adding RO as needed throughout the week. Soft corals started to fail. Basic stuff, mushrooms, pulsing xenias, green star polyp. Stuff you can't kill. They had not meant me. Changed 4 weeks ago to fancy water - Reef Crystals - all water I use is premixed at store. Their fish are all on same system and thriving. No other clients with problems. I trust them 110%. First I lose, blood shrimp, soft corals slowly, and within 1 week of blood shrimp entire tank is basically gone. Coral beauty, 2 clowns, banggai cardinal, 2 cleaner shrimp. Theory was tank was somehow compromised with cleaning agent, something in the air. Gut tells me no. I am the only one with hands in tank. Dilligent about feeding, cleaning, tools used. Water changes and tank cleaning have been weekly for 1 1/2 months. It is beautiful to look at but everything is gone except for 5 snails. They are Cher and have survived. Snails are slowly losing stuff to feed on though. SO....... because the story isn't long enough. Went into fish store, they are stumped, sad, I am perplexed, devastated.......... another water change, fancy water, reef crystals, 8 gallons and then a filter cleaning sack in filter to take out all impurities and whatever the heak is in tank. Ran through system 1 1/2 weeks, water testing in store and at home perfect. Fish store "your water is perfect" YEAH! oh no there is more........... another water change 8 gallons, another tank clean...............water perfect..............add 2 cheap clowns to see what happen...........acclimate 40 minutes................add to tank..........swimming happily........find each other.........all is good at 8pm...... feed, they eat. check on before bed....6 am floating fish http://www.reefcentral.com/forums/images/smilies/uhoh3.gif (had to add a character) did not even last 12 hours. something is toxic and i don't think water has been compromised. there were 3 water changes in between die off and new fish. tank is beautiful. please any advice??????? last readings:
nitrate 0, nitrite 0, alkalinity 300, ph 8.4, salinity 1.024, ammonia 0. (not kidding) green star polyp is opining so slightly and super tiny, its like it is trying to say mom we are still here but struggling. HELP!

i will end with this........ my theory, remember rookie here but have maintained tank for 2 + years with no issues and great result. i have never siphoned the sand bed and it is about 3 is inches. when i clean i fluff sand, usually the brown on top. then i suck out gunk as i remove water to swap out. can the sand after 2 + years become toxic? emitting a gas to kill off tank. i never go that deep but a silty film will cover bottom of sand bed. 20 lbs of live rock also in tank.

any advice or thoughts are greatly appreciated. i have learned so much from all of you and miss my hobby.

 

[davjbeas]

You could try some nassarius snails and a diamond goby to sift through up the sand bed.
if you can filter your water through a Polyfilter it should show you by color what was absorbed. GL.

 

[CStrickland]

There's lots of reasons a tank can crash, and lots of reasons new clowns can die. Sometimes they overlap and sometimes not. Some softies can poison a tank when they get mad if you arent running carbon. It's more like the sand gets "full" and doesn't take up phosphates anymore so you start having algae probs, you have to poke into it to let gas out and it smells like rotten eggs really bad so you'd probs know if you did that.
It often takes longer to un-crash a tank than it did to crash it in the first place. If you've only gotten the maintenance on track in the last month it's on track to recover.

A couple things to consider:
- what do you mean changed to fancy water 4 weeks ago? Are / were you not doing regular water changes of a few gallons a week? It sounds like you were and vacing the sand so I'm confused. Or maybe that's just the last month or so?
- that alk can't be right, that's like 17 dkh
- can you post a pic of the tank? it can tell a thousand words

 

[Newstead]

I would wonder about the sand and the alk. Could you try siphoning 1/4 of sand bed at a time, doing water changes between each, then a final 25% change? Then check parameters and snail/coral health before trying fish.

 

[rtecanoe]

I would also suggest using polyfilter pads. Pretty cheap and may tell you by its color what the problem is. I would check for stray voltage in the tank too, maybe a piece of equipment is leaking electricity.

 

[splix]

alk 300? If that really is 17 dKH that is insanely high, which would also mean calcium and mag are way off too, which I notice you didnt post. Did you test them? If you and your LFS are both testing it though, that would have thrown a red flag. 8.4 PH might tell that story. It's a tad high but in an OK level, and for sure not in a clown dying over night type level.
Voltage in the water might be a good suspect. That is something that might cause your issues without showing up in any test kit. I know a lot of people dont even think about it and never test for it. I actually did test mine the other day from reading a thread on here about problems with it. I just use a multimeter with both probes in the water. If you dont have one, they're very cheap and come in handy in a lot more places around the house.