Chemistry confusion

[Eco Owl]

Hi all,

I started fisheless cycling my 1100l system a few weeks ago. When I first put water in the system I treated the water with a pond prep to neutralize the chlorine etc.

All the levels were within the recommended limits but I did not have a kit to test for Amonnia. On day 21 I received the amonnia test kit and the ammonia levels were zero (as were the nitrites and nitrates).

on the same day I added some plants to the system's growbeds as well as 10 goldfish to the tank. i also added 2 small rocks from an established pond. From this point I started measuring for ammonia every day. On day 24 ammonia zero, I missed day 25 but on day 26 ammonia level 0.5 mg/l. Day 27 and 28 ammonia level is back to zero. Nitrates and nitrites still zero. PH still 6.8.

Did I miss something?

I am keen to add my Talapia but don't want to do this too soon.

Thanks,

Eco

[matthew ferrell]

No, your ammonia increased due to an increase in ammonia creating critters.  Your bacterial community will grow until one of two things happen.  There is not enough food(TAN, NO2), or the surface area for them to grow on becomes limiting. 

Add the tilapia.

I would also keep an eye on the pH.  It is fine for now, but a little low for the lack of nitrification already in progress.  Nitrification consumes alkalinity, and produces carbonic acid.

[RupertofOZ]

There isn't enough nitrification going on... under the current load.... to make any significant movement of pH at the moment..

[Eco Owl]

Thanks for the feedback, I am looking forward to adding the Talapia later this week! :D

PH is now 6.4 everything else unchanged. I guess there will be some movement when I add the fish.

[TCLynx]

Get some crushed oyster shells or limestone chips that are usually sold at farm or feed stores to use for chicken grit.  Put them in a mesh bag or stocking and tie it up and hang it in the fish tank to keep the pH from dropping too low.