My fish are dying

Hello all. I am new to the hobby of SW and to this forum. My problem is that I did a water change yesterday and noticed after that some of my fish were breathing hard. This morning I woke up and my Wrasse, 2 yellow tail damsels and chromis are dead. My tank has been set up since the new year and I have had only problems with nitrates due to the fact it is a FOWLR tank with no sump or protein skimmer. I know, I know. So water changes every week and cleaning my canister filter twice a week. I am saving to put in a better system. The only test kit I have is an API, ammonia,nitrite,PH, and nitrate. The only thing that is reading above zero with this test kit is the nitrate. 20 ppm. I use water from our home RO system for water changes. Any help would be great because the rest of the fish don't seem happy. I have a long spine sea urchin and was told they have poisonous spines. Could it release toxin into the tank?

Well a lot of people will tell you that if you don't run a protein skimmer, have a sump everything will die you will fail blah blah blah. But I'm not one of those people, afterall you have to know the rules well to break them right? One of my reefs(smallest tank) is a 55 gallon with two canister filters. no sump, no protein skimmer. No problems whatsoever. But this is because I do weekly 40% water changes with ALL my tanks.

Your fish shouldn't have died because of 20ppm of nitrates so there has to be something else. You used RO filtered water so you're good there. Is there anything that could have leaked into your tank? Unless your urchin Is dead you shouldn't worry about him I've never had an issue with them while they're alive. Do your fish show any signs of disease or parasites?

Thanks you guys for your suggestions. I should have gone to the store today I guess to get some AC. Im not running any right now. The local fish store PetSmart is closed. Hopefully the fish will survive through the night. I have wondered about something getting into my water change bucket too. I changed my membrane and all filters in our RO system about 3 months ago.

The same thing happened to a friend of mine. His mother-in-law was just helping clean the house but didn't know she was using a bucket he had dedicated to his fish stuff. He never suspected it until he saw his tank gasping for air. Soap coats fish gills making the fish suffocate.

Would you be interested to learn how some really simple, no cost things could lessen water changes and filter cleanings. These things might also make your tank look even better than it has looked before.

Aloha
Mark

Oh and by the way, here is a big fishy welcome to the WMAS.




Edited by Mark Peterson - June 09 2013 at 9:53pm

FYI TO ALL. I am pretty sure I found the problem. I just bought a new Hydor wavemaker off of Amazon and put it in the tank to replace a cheaper one that I had.... Well, it had quite a bit of oil on the impeller shaft. I didn't notice it until I was cleaning my canister filter and noticed there was oil floating on the surface of the water in my canister filter. When I pulled out the wavemaker my hands had some oil on them. NO JOKE!!! I hope this helps. When in doubt clean, clean and clean again before any thing goes in your tank. Thanks for your help

One other thing to be conscious of is the salt mix.  I always mix up my water for my water changes and stick a power head in it and let it sit for about 24 hours.  I point the power head towards the top of the water so it can get some air exchange.

Just FYI, there's a few of us in Cache Valley.  I'm in North Logan.  PM me if you need something, I'll see what I can do.