Low pH and High Ammonia w/ Babies

[Arwen Vaughan]

I have 125 gallon tank with 5 adult tilapia and probably about 100 to 200 of 1/2 inch babies. I was surprised that the adults were not eating the babies this time. Last time there was a birth in the tank they were all eaten. Anyway, I checked the water today and the pH was about 6.0 and the ammonia appears to be in the 2-4 range.

What should I do? Long term I know I need to get rid of some of these fish, but I don't have another tank ready with good water right now. So, what should I do to slowly get the water in better shape? Should I bring pH up slowly and do a water change/addition? I added a bit of CaCO3 and just barely started bringing the pH up. I am trying not to overreact and do too much. Looking for some advice first.

And / Or, should I pull out some fish? I could harvest the adults right away if that would be best, but I really like having good breeders? Or, I could start getting "rid" of babies since I don't have another tank. Preferably, I would like to setup another tank to keep the babies in and keep my breeding adults going as well.

Also, does anybody want some free babies here in Northwest Denver? :)

Thanks in advance!!!

[Rob Nash]

sounds like you understand your options..  the low pH is most of the problem.. bacteria doesn't do as well at converting ammonia at lower pH levels. add some river rock to your media to the tone of 30% this will fix the pH once and for all.. I haven't adjusted pH in 3 years.

I would get a second tank together and get the babies out.. they make a lot of ammonia.. do an exchange for now and slow down on feeding.. only once every two days or so.

[Alex Veidel]

Water change and slow feeding...my thoughts exactly.

Rob Nash said:

I would get a second tank together and get the babies out.. they make a lot of ammonia.. do an exchange for now and slow down on feeding.. only once every two days or so.

[Arwen Vaughan]

Thanks guys!

Ok, I'll get a regular fish tank (regular filter not aquaponics) started today. What size tank do you think would work well for some time w/ roughly 100 fingerlings? I know they will outgrow this in short order, but what would you think is a decent short term (1 to 2 month) solution?

The pH came up a few tenths over night (because of CaCO3) and is well on it's way, so the bacteria should be able to do it's job a little better now. I'll just keep doing water changes on the tank and fish out any solids I guess. I don't have a chlorine filter, so how would you remove chlorine? Is it ok to use regular fish tank de-chlorination drops, or is this bad for the fish or plants? I usually just let 5 gallons of water sit out for 24 hours to remove chlorine, but I will need way more water for this task. I have never had to do a water change before....only water additions.

I'll also harvest a few of the plate sized adults and try my hand at sexing them while at it  (never tried it before). I will probably just eat the females because I don't want this many babies again!!!! This is too stressful! I still have more babies then I can handle so if anyone needs a few I can give you my contact info.

Does this all sound like a decent plan?

[Rob Nash]

here are some pics that may help..

use some food coloring to see better,, the female is pretty obvious once you find one.

female - has a flap with a hole in the middle of it.

   

 

 

 

 

 

 

 

 

 

 

 

male  - has just a flap, with a much smaller hole on the very tip. 

 

[aubrey sloan]

thanks Rob

 I was having problems myself trying to put a breeder set up.

Rob Nash said:

here are some pics that may help..

use some food coloring to see better,, the female is pretty obvious once you find one.

female - has a flap with a hole in the middle of it.

   

 

 

 

 

 

 

 

 

 

 

 

male  - has just a flap, with a much smaller hole on the very tip. 

 

[Arwen Vaughan]

Great! Thanks for the pictures and other suggestions. I have done some water changes on the system and brought the pH and ammonia to decent levels nice and slowly, and the fish are acting normal now. I will start harvesting the adults tonight to slowly reduce the poop in the tank. I moved as many babies as I could get out into a 20 gallon tank (with 40 gallons of filtration).  Also, I bought a couple of 55 gallon drums to grow out as many babies as possible. Thinking about 50 fingerlings per drum for a little while.

I still have a couple of questions though that would be nice to have answers for...

1. Is it ok to use regular fish tank de-chlorination drops to remove chlorine?

2. What is the rule of thumb on fish density when dealing with lots of fingerlings?

[aubrey sloan]

      I let water stand for at least 24 hrs 

 And  my first fry tank was a 12 pack cooler with air stone,every day after work I would do a 10 percent water change from 

the the water I put out the day before.Only had 27 small fry I think were 1/2 inch to 3/4 inch long blue tilapia. Then I moved them all to a 55 gal barrel till they were in the 3 to 4 inch,then to a 275 gal tote.did not loose a single one. Air stones ,air stones.

you can never have enough air.

   good luck