Backyard Aquaponics
A place to discuss aquaponics

Hey all,

Hope all are keeping well.

I am seeing a pH of 7.6 and ammonia at 0.25. Would this be dangerous tho i wish to keep my pH to 6.5 and 7. At the moment i have Carp (Stripped catfish) stocked with Red bellied nutter. approximately 700 all together in a 14,000 liter tank. Recently due to the rains my pH has increased.

I am thinking for adding Phosphoric Acid to lower the pH. Can somebody please comment on the dosage and if there is any relation between pH and Ammonia ? Will higher pH with lower ammonia kill fish or is it the other way ?

Hiya georget, ammonia, pH and temperature are all relative.
Use hydrochloric (muriatic) acid to adjust top up water before adding to the fish water moving the pH no more than 1 point per day. HCL acid adds beneficial chlorides for the fish.
Here’s some handy information. http://ibcofaquaponics.com/information/ ... nd-charts/

Thanks i've come across that table earlier but just not sure how much is dangerous. Based on the table my UIA is at
0.0236. So based on the calculation mentioned here(https://thefishsite.com/articles/ammonia-in-aquatic-systems) it is not toxic but its best to decrease the ammonia levels. Is my assumption correct ?

Assuming your calculations are correct then your assumption is as well. I find it easiest to use the chart Skeggley linked to because the test kits we use test Total Ammonia Nitrogen and the chart is setup using TAN as well so no conversion is necessary. Referring to the TAN chart, you want to keep the TAN below the level on the chart for your pH and Temp (Found in the cell where the row and column for your pH and temp meet). You should always try to keep reasonably low TAN though because fluctuations in pH and temp could potentially throw it into the toxic zone where you could lose some fish. It's difficult to say exactly what level fish losses will occur at since different species have different tolerances. You'll find that while fish kills do happen as a system gets more mature it is less of an issue.

FWIW, it's really the NH3 (unionized ammonia) and not the NH4+ that kills the fish so that's what we're really trying to keep low. Your options for doing this are to stop feeding, lower pH, and lower temperature. Things like algae and fish kills or dead animals often cause issues that make control more difficult so watch for these.

Thank you Scotty !
I did not know that the chart earlier shared by Skeggley was something already calculated. I will follow that as it avoids the need to calculate it further.