AQUAMAN

I SET UP A FORTY GALLON HEX TANK TWO WEEKS AGO AND HAVE BEEN RECYCLING AT 15% EXCHANGE EVERY THREE DAYS. aLL READINGS ARE EXCELLENT AND IN BALANCE WITH EACH OTHER. I HAVE (or hAd) TWENTY TWO FISH ADDED AT FOUR DAY INTERVALS. dANIOS, TETRAS, RED FIN TETRAS, CORY CATFISH. tHREE DAYS AGO I STARTED TO LOSE THEM VERY QUICKLY. I HAD JUST ADDED THE RED LONG FIN TETRAS. IS THAT AN AGRESSIVE FISH? I SUSPECT A KILLER SOMEWHERE! ALSO ONE OF THE ZEBRAS WAS HARASSING OTHER MEMBERS OF ITS GROUP. OUT OF SIX I ONLY HAVE TWO LEFT. ANY IDEAS OUT THERE? HAVE I OVERCROWDED THE TANK? DOESN'T SEEM SO UNLESS I DID IT TOO FAST, BUT MY AMMONIA READINGS ARE FINE. APPRECIATE ANY HELP.

Sniperelite8243

aggresive fish, yes but very unlikely in this case.
the minimum you wait after you set up a tank is atleast a month to be sure. 22 fish in 4 days. theres your reason. add 4-5 fish every five days to let your bacteria grow to handle the higher ammonia level. the bacteria couldnt keep up so the fish most likely died of ammonia poisonong. by adding 4-5 every 5 days your colony grow to handle the needs. but the rate you added fish was just way to fast.

good luck
&
welcome to the forum

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Tommy Gun

I think that your problem would also most likely be found in your water parameters. You state that your ammonia levels are all 'fine', however there are also nitrIte and nitrAte levels to consider, and even a few more after that.

Can you tell us what your ammonia, nitrIte, and nitrAte levels are?

It seems as if you already recognize that ammonia is going to be toxic to your fish. However, nitrItes are just as toxic as ammonia, and nitrAtes, while still toxic, are deadly in higher amounts only.

You may want to look over this 'sticky' article about cycling a fish tank to familiarize yourself or re-familiarize yourself with the process: http://www.fishtankforums.com/5-fres...-aquarium.html

This article will also give you some insight into how stocking a fish tank can impact the water quality. While I realize that most of your fish are small, and your tank is 40 gallons, having 22 fish in a tank is going to result in a lot of wastes and thus become difficult for you to keep the water quality in healthy ranges.

Knowing your water parameters (ammonia, nitrite, and nitrate) would really help us help you.

BJP

It's very hard to get batches of fish that are completely healthy. After the first batch goes into a tank, any additional fish should spend up to a month in quarantine in a seperate tank prior to transfer. Every time you add more fish straight from a store it's like roling the dice. You may get lucky 10 times in a row but eventually you'll bring in something that transfers to the previous fish and you lose some of all of them. Quarantine tanks can be small and inexpensive and with only a few fish saved you can recoop the cost of them quickly. In an emergency a simple bucket with sponge filter can work although you lose the option of viewing the fish closely.

AQUAMAN

Thanks For The Advice. That Number Has Been Reduced By The Death Rate And It Seems As Though There Is Now A Balance As I'm Not Losing Fish Anymore. Will Wait Quite A While B4 Adding Anymore Fish.

AQUAMAN

Regarding The Quarantine Tank, Do I Set It Up With My Water And For How Long A Period Of Time Do I Keep New Fish In It? Thanks For The Help.

AQUAMAN

Not At Home Right Now, But Nitrate Level Has Remained Very Low With Some Flucuation. Nitrite Has Been Almost Non Existent With Ammkonia Only Reaching As High As 1.5 With A Regular Ph Readingb Of 7.0.strange Thing Is That The Level Of All These Components Has Never Flucuated Since Tank Set Up. I'm Using Well Water Onjly Treated By A Water Softener (salt). No Chlorene In The System. Thanks For The Help

BJP

Yes, have the water about the same as what's in your main tank unless your source of fish has water extremely different then it can be used to match the stores water and gradually changed to match your own.

I would say a minnimum of two weeks after all signs of illness have passed and no deaths have been seen. With a healthy batch that could be only two weeks total if no problems develop. In some cases much longer but at least you're finding out about a problem in a smaller tank that's cheaper to medicate, easier to service and observe in and not expossing the main tank to the problems. After a while it becomes a routine, add fish from QT to main tank, aquire new fish for QT, repeat until main tank is full then toss the QT in storage for emergencies or impulse purchases. If I leave it full of water something will end up having it as a permanent home then it'll be useless for it's original purpose.

BJP

Test some water before it enters the softener and out of the sink for ammonia. If you get a testible reading you have a bigger problem than the tanks to worry about.