Fish died, crabs, snails and urchin are at a standstill?

[Sidhefey]

So at 3am yesterday I noticed my clownfish were breathing really hard, I thought the salinity was too low, but couldnt find the tester.When I did, it was perfect, the coral appeared fine and lively except a mushroom (some slime was around it? or goo.) I also noticed the urchins spikes were on the sandbed, and remembering that from reading somewhere, that was a BIG warning sign that something was wrong with my water. The snails and hermit crabs are staying still, not moving whatsoever (but alive)

I then quickly changed the water 50%, (keep in mind I did earlier that day a regular 10% and there were fine the whole day). Unfortunately I was too late for one of the clownfish. But once I did change the water, the crabs snail.... urchin were all lively again. And the clownfish was breathng normally.

However this morning I found the fish dead(did another water change 50%, mixing my own salt water and put the right conditioners in it etc. and Some TLC bacteria), but every other inhabintant was fine.
This afternoon 3 hours later... they are all at a standstill (alive but still, and less lively) again. I'm not sure whats wrong... here are the test results.

Nitrite reads 0.3mg/l
Ammonia reads 0 mg/l
pH is 7.7
KH is 10

 

[Sidhefey]

The coral is fine however, though the mushroom one that had slime on the side of it (don't know how else to explain it) is withdrawn.

 

[Flake]

How long has the tank been established? do you have a test for nitrates?

 

[Sidhefey]

No the kit I bought has only pH/KH/GH/Ammonia/Nitrite

abit longer then a week @_x. It my mother's and I experiment tank so to speak. Our trainer one till we're ready for a bigger one.

Its a 14g/12g we bought on Craiglist that was brand new.

The urchin was purchased the second day and was fine throughout the whole week. Our newest inhabitant is the mushroom coral thats spotted green or orange (it changes colors on me)

The fish are tank-raised, same with the hermits. I feed them once a day with brine shrimp that are frozen. I put Aquasafe and TLC. And Marine snow (once a week) for the coral. And thats it.

 

[Mitchell0605]

That Nitrite, though too high, isn't enough to cause this. I think you need to test Nitrate.

 

[Sidhefey]

So Flake says my tank isnt cycled, I'm probably starting over soon with my SW and move it to a bigger tank once said tank has cycled on its own for a month. Hopefully these live till them

 

[AMDPhenomX4]

I would suggest starting with a 10G tank filled with Ro water from a store and putting all the inhabitants in it. What water did you use on this tank?

 

[Tony B]

do u plan on making it a reef tank or a LFO ? yea patients is a must, go in small step this way if a mistake is made or something happens unexpectedly it wont cost as much to start over. though i would get a test kit for nitrates as well

 

[thincat]

I don't think you cycled this tank. Even if it's cycled you added to many animals and to fast. I don't understand why people rush the process of a SW tank. Remember that what you add is a living animal and all processes should be checked before we put them into our tanks. You started your tank on March 4th and even if it was cycled you did not give it a chance for it's bacteria to catch up with the new bioload. The only choice you have is either return the animals to your LFS or get the proper test kit and do Water changes to keep all readings at it's proper levels.