ABN juvenile die off

I had roughly 150 babies that are now approaching 3" in length including their tails. A second batch of babies (roughly one inch) are also in the same tank (150 gallons). Forty of the juveniles were sold to a local store with zero losses. No baby losses that I can see. It all looked wonderful until this past weekend.

All of a sudden I started losing the juveniles, first one then five and then four, then tonight the worst of all, twelve more.

I have been doing daily water changes of 35 gallons, the ph of the water in the tank is 6.8, no nitrates to speak of, and the queerest part of all is none of the adults or the new hatch have been affected.

I have kept fish for 44 years and never experienced anything like this, I am at a total loss. Is there something I am missing.

All comments, questions and/or queries welcomed.

Thanks in advance

Steve

I'm assuming that you have checked all of the parameters of the water including ammonia. One of the things that people often over look is that the shear bio-load in the tank is huge and unless you are doing massive daily water changes or have the tank hugely over filtered then there will always be an ammonia issue. For example, my grow out tank has 2 sponge filters and a 2200l/h canister leading to an overall filteration rate of about 12 times per hour.

the other thing to check is that there is no bacteria or other nasty going around in your tank. I use a UV sterliser on my grow out tank to be 100% sure that the water is as healthy as i can get it.

Finally, I would throw some activated carbon into the filter/tank for the next 3 weeks. This can help mop up any nasty chemical that may have found its way into the tank. make sure you remove it after the 3 weeks though.

Hi Doug,

Thanks for the idea of charcoal that is something I can do quite easily. The filtration at the moment is a RENA Filstar 3 and a Marineland Emperor 280.

I also have a couple of smaller HOB's that I can add and will also try the UV idea.

Water changes are 35 gallons a day, would you increase this or keep it as is?

Thanks once again.

Steve/ Wooster

Well I am not sure if it was the addition of the charcoal or a filter I picked up from a buddy (Marineland 360) but all seems to have settled down again. (Said he thankfully) I had checked the water parameters and all looked good, just to be on the safe side I had said buddy check the water with his kit and the ph was 6.8 - 7.0 no ammonia gh 23 ppm.

Also added a nine inch air-stone, just to add a little more movement.

So at the moment is filtration is roughly 980 gallon per hour ( 3709.7 LPH) , I will also be adding a couple of big sponge filters and hopefully (fingers, eyes, legs and toes crossed) that will take care of things.

My beloved Vicki has even set up a reminder on my cell phone to change the charcoal in 3 weeks.

What a woman, not sure what I would do without her

Thanks again!

glad to hear that it is all settling down. fingers crossed it stays that way