Backyard Aquaponics
A place to discuss aquaponics

Hi guys
It seems that my filter is working pretty well on filtering ammonia now.
The reading on ammonia is almost zero all the time. which is something i am really happy about.
But, the nitrite is HIGH (3 ppm to 5 ppm).

Have you guys experienced the same situation before in the beginning?

Do you guys have any suggestion on how to keep the nitrite low?

How do i make sure my filter box would not develop bacteria that kills nitrate?

Thank you

The bacteria that break down nitrite into nitrate are different then the ones that break down ammonia into nitrite they might not colonize at the same rate in a new system.
Temps, Ph, surface area, and a whole host of other factors play in there too, if the problem persists I would need alot more detailed info to be able to formulate a good guess.

Do you have fish in the system and if so , salt to 1ppt. That is one gram of salt for every litre of water in the system. ie 1kg for 1000L

what kind of filter do you mean? if you don't have enough surface area, you'll never complete the cycle...
but if you've followed recommendations here and are stocked and filtered appropriately, then the cycle may not be complete.... how about some details/pics?

Add salt to 1-3 ppm, and then do a water change to reduce the nitrite levels and wait for the nitrate bacteria to establish. May need to do more water changes till then.

I'm in this position myself.

Yeah like what the others suggested, and if you have fish in your system you might wanna slow down/stop on the feed for a while too. I was in the exact situation few weeks ago.

Thanks everyone
But would the salt damage the lettuce's root?

To Keith: mine is a 45 gallon fish tank with 10 small baby goldfish, and a 20 gallon filter box with 5 matala pads( from low to high density). The filter box's temperature is 18 Celsius and it is aerated all the time.

Thanks

I've got a variety of plants in the GB, the diversity should help offset any impact of salt.

When you do water changes, remember that the diluted salt also gets changed out, you'll need to 'add more salt in' to maintain the levels.

Had the exact same problem when I started to cycle. NH4/NH3 dropped to zero, but NO2 just wouldn't drop. I salted my system and just waited. After about a week, I just stopped feeding for two days and my NO2 levels just dropped (most likely I was just over feeding). The salt will not harm your plants if you salt to 1ppt. Its definitely a good idea to do a water change in this case. I didn't do a water change, but that was because my fish were from a local lake and were kinda impossible to kill. Even if the fish died, I figured I would replace them once the NO2 disappeared. It would have just given me another reason why I have to go fishing.

Alright i will try that
Thanks guys

Imho I am not sure that a water change might be the best course. If you have a chloride in the water to protect the fishes gills I would get as much DO in the water as possible to complete the cycling rapidly.

what do you mean by DO?

The cycle relies on oxygen, DO is dissolved oxygen. Putting a chloride in your water and then doing a water change can effect a number of parameters ie the amount of chloride, the Ph, introducing chlorine in some form or another etc.
Assuming you have a chloride in the water you should ensure the bacteria can cycle as fast as possible, without screwing up their environment.

i believe my system has a very high DO.
And the water is very low on chloride.

Put some sea or pool salt in as Mantis recommended.