[leebca]

No need to appologize for confusing me, Dave. I can confuse myself quite well on my own!

A couple things to think about:
The source of nitrites is the nitrification of ammonia.
The conversion of nitrites to nitrates is slower than the conversion of ammonia to nitrites.

Quite often when the tank is disturbed (a cleaning that has been put off to long, or someone wanting to change the design, substrate, etc.) there is a boost in ammonia by making decaying matter more available to bacteria. There is a bacterial bloom which reduces oxygen in the water and increases the ammonia level. In your case, it could be dead fish or higher life form(s) that have died and is now rotting, also increasing the bacteria numbers and ammonia.

The bacteria responsible to convert ammonia to nitrite are usually 'on the job' and can reproduce quickly to handle the load. But not so with the bacteria that convert the nitrites produced, to nitrates. Either they don't reproduce that quickly or they don't metabolize that quickly, or both, to keep up with the surge in nitrite wastes being produced by the other set of bacteria.

It's a sort of chain of events with every link taking its unique time to respond to the increase in waste levels.

[dangerousdave]

OK great, thanks for clearing that up, I just changed 20 liters of water and now Im changing water in the QT

[dangerousdave]

Hm i pressed enter by misstake but cant find a "edit" button? hm..

well as I was writing: ..change water in my QT due to the medication is done and I have added carbon as well.
I must be under some kind of spell... Looking into the tank as Im taking out the water I see a tailfin sticking out of the outlet in the wall of my cube... YEY, one of my small clowns managed to jump the fence and got sucked into the powerhead and got through and went through the pipe to get stuck in the outlet... Great.. So now Im down to two fish. . .

well well if this was an easy hobby everyone could do it : )

Its sunday and tomorrow my vacation starts, gonna get tanked swedishstyle tonight! (kinda like irish at a wedding, just worse... )

Cheers
Dave

Hm the funny thing that this message got a "edit" button on it and the one before didnt? hm well well!

[dangerousdave]

Ok I think I got a spell on me.. One of my two clowns ended up in the QTs outlet (jumping the "wall" and getting sucked through the powerhead, through the tube and out the outlet). Saw just a tailfin sticking out. Then find that the ammonialevel is high and put the two remaining fish back in my main tank (one clown and one firefish). This morning I got up to find the last clown stuck in the outlet as the otherone did back in the QT) suicide one can think.. So now my two oldest fish are dead and things are actually getting boring? And to boot it all I see that my coralls are shrinking?? they are totally shrunk in size. . . I´ve had a temp about 80 to 84 degrees in the tank but got it under 80 today. Got a ph at 8.3 and Kh at just below 6. I dont have Ca test but change about 20 liters of water each week so I dont think I should have a problem with Ca. So whats the problem? got close to 100 watt T5 in my 24gal tank. Salt´s come in just under 1.024 now.

Lee where are U??? : )

Dave

[leebca]

Not good, Dave, obviously.

I think you've over-engineered the QT. Just one corner sponge filter is all you want/need. No water tubes; no circulating powerhead; no other equipment. Fish can't/don't get hurt with a sponge filter. Keep the QT as simple as you can, when it comes to equipment. I'll share the blame here. I realize now what you meant when you wrote:

I did have a 1100 l/H powerhead in the tank as well before, but used it to upgrade my QT with. . .

You put the powerhead in the QT. I didn't catch that or I would have suggested you not do that.

The QT:
Small aquarium (10g minimum, but 15 gallon preferred unless you need it to quarantine fish over 3" in length or tangs over 2" in length, then you need larger);
Sponge filter (tubing, air pump) - -You need two if you go w/a larger tank;
Cover (to prevent jumpers getting out)
Light (just so you can see the fish and the fish can see their food)
Heater (if you need it to keep the water temp steady); and
A place to put all the above.

That's it. Usually a US $40. or less investment when you get a set from a department or chain store with a pet section in it.

A high ammonia and nitrite reading in the QT is not unusual. If the sponge filter is 'seasoned' in your system, then transferred to the QT, the sponge filter performs the biological filtration. Since you don't have one 'seasoned' with the needed bacteria for nitrification, you will have to do large (even 90% or more is okay) water changes daily or twice a day in order to control the ammonia and nitrite levels. This is normal, without having an active biological filter.

Can't bring back the fish loss, but you can prevent any further losses. Return to the basics. For the QT:
http://reefkeeping.com/issues/2004-1...ture/index.htm

You might get better help in the Reefland Reef Aquariums Forum regarding the corals. Corals do close for sometimes 'normal' and 'unknown' reasons, but it shouldn't last for long.

I don't know the needs of the kinds you have, though I can say they are usually pretty sensitive to water quality (more than the fish). Since I don't work with calcium and alkalinity that much, I'm unsure if your alkalinity is right for the corals. If it was just fish, I'd recommend an alkalinity of no less than 8, though. I do know there is a relationship between calcium, magnesium, alkalinity, and pH, so the reef aquarist has to review those parameters whenever there is an indication of trouble. The reef aquarist should monitor ammonia and nitrite levels, plus: phosphate, iodine/iodide, and nitrate levels, too. How many of these are you watching? Can you start testing for those?

Water changes are good. I would give your freshly made up salt water a test for every test kit you have (pH, ammonia, nitrite, nitrate, alkalinity, phosphate, magnesium, silica, etc.) to verify that the new water is proper. It is not uncommon for the aquarist to not realize sometimes that the trouble is coming from the source water or salts, so best to make sure you've eliminated the possibility that you're unknowingly adding something when you make a water change. Be sure all test kits are current and not expired, and that you're performing the tests properly.

When you have the above information, you might post the test results along with the lighting and circulation you have in the tank, in the Reef Aquariums forum and ask there if there is something you can do about your corals.

I'm online more frequently during the day on weekends.

[dangerousdave]

allright, I´ll give the reefforum a try and get some more tests. Thanks Lee!!

Dave