High nitrites

[Brian Hillestad]

I have a tilapia tank with +/- 40 tilapia in a 600 gallon tank.  I have it draining to a hydroton bed (2' x 3') and then to a raft bed (3' x 14').  Lettuce and kale doing well, tomatoes have started to fruit well too.  There is a total of about 50 plants I have as filters.

I tested the water last night:

ph: 5.5

Nitrites: 4 ppm

Nitrates: 120+ ppm

 

Fish are breeding well, and I saw new fry yesterday.  Any suggestions on raising ph and lowering nitrites?

Thanks.

[Keith Rowan]

the nitrites are bad news for the fish and fry.. especially the fry.. i'd suggest to salt to 3ppt immediately, hopefully to avoide "brown blood disease"

for the amount of filtration you have, you are overstocked

[Harold Sukhbir]

Hi Brian,

How long ago did you cycle your AP? Have you been doing water test since then and what were the results? Have you been buffering the system? I noticed that your PH was below 6ppm, which is too low for the nitrifying bacteria in your AP. Below 6ppm the bacteria is inhibited.

See this 

http://www.bioconlabs.com/nitribactfacts.html

[George]

No telling what the PH really is - could be lower than 5.5

Stop feeding

[Brian Hillestad]

Harold:  I cycled about 4 months ago.  I test about every 2 weeks.  

George:  Thank you.

I think some of the issue is water changes with acidic well water.  I did not feed them today, and will hold for a bit longer.  I will now test the next few days.  Thanks for the responses.

[Keith Rowan]

like Harold said... low ph can inhibit cycling..or completely crash your system (set it back to the starting point).. get your ph up, but do it slowly..

[Harold Sukhbir]

Hi Brian,

And don't worry about feeding the fish, they can go a very long time without. It may take you a couple weeks to recycle depending on your water temps so try to be patient with the process.

[Brian Hillestad]

Water temps are holding around 78 degrees.  I will hold off until I get the ph back up.  Thanks