Backyard Aquaponics
A place to discuss aquaponics

Dors anyone know the allowable nitrate and nitrite levels allowable in a new system please?
They are up to .05 and 10?
Thanks

Do you mean nitrite and nitrate? .05 and 10?

Do you have any fish in your system?

What is the pH?

Have you added any salt?

What is the history of the ammonia levels? Are they going up or down?

Don't worry about the nitrates they won't hurt your fish unless you get much higher concentrations.

Presumably you haven't added anything to give a nitrate reading so the nitrates that you are detecting have come from nitrite converted into nitrates. If so this means that your system is getting close to being cycled. The thing is without knowing what you did yesterday or the day before its hard to say what to do today. A nitrite reading or 0.05 is rather low in fact I think you might mean 0.5? If so then again it depends on your level of salting and is this reading going to go up because you had lots of ammoina at the same time and where still feeding your fish or go down because you didn't and weren't?

It is a bit hard to be clearer because the values you have given don't make a lot of sense and even if you have just made a couple of typos it is still hard to know what to advise without any history.

Hi thanks for answering for me, yes I have had fish for about 10 days and up until a couple of days ago ammonia, nitrate and nitrites were 0 but atm nitrates are 5.0 and nitrites are 0.25 I havn't added any salt. By the way what happens when you do add salt and under what circumstances would I need to?
So far ammonia level remains at 0
PH levels are in an acceptable range were 6.6 but now 7.2
I really just want to know what is the acceptable levels of nitrate and nitrite incase they are dangerously high and I kill my fish?
My master test kit goes from Nitrite 0ppm-5.0ppm
nitrate goes from 0ppm-160ppm
thanks Norman

Hi Norman.

Somebody will jump in with the pH/NO3 toxicity chart (search for it) but I see no problems with those levels, so long as you do not feed the fish until nitrite levels go back to zero.

Note, a higher pH means nitrite is less toxic (i.e. at 7.2 you can have a higher level of nitrite than at 6.6)

Nitrate. Mine is off the scales and has been for almost 12 months. The fish in there are from 3 years to fingerlings this year. Not the best but don't get hung up about nitrate levels under 400ppm.

Salt added to the tank dissolves. Having salt in the system reduces fish stress and thus reduces the incidence of disease. It can though be harmful to some types of plants (strawberries). Again search for the required levels (off the top of my head 3ppm, 3kg/1000l). Some people carefully dissolve it prior to adding. I just dumped it in.

And just in case you missed it. Don't feed your fish until nitrites get back to zero. They will last 2+ weeks without feeding.

Salting
Nitrite issues - 1ppt = 1KG per 1000L or 1gm per L
Parasites - 3-6ppt
Dip for parasites - 30ppt - Not all fish will be able to handle this level (catfish would probably have troubles) so use with caution and remove fish that show signs of distress (roll on their sides, or act strange). 30 seconds to 10 minutes is recommended by the Merck Veterinary Manual.

There should be a cycling support group on here...seriously.

I think I finally might have finished cycling???
My readings changed OVERNIGHT. seriously. I had to check twice because I didn't believe my nitrites and nitrates could fall that fast. the nitrites went from intense magenta to light blue in 24 hours.

But what really confuses me is my NITRATES went down to almost nothing also and they were in the pomegranite red zone (40-80ppm If I Remember Right?) don't understand...the plants have been there all along. what happenned?

make sure you clean the tubes out between tests..
and the "change" can be pretty dramatic when cycling..