expansion5th

I'm in the process of cycling a 30g...

Once it's done, it will only stay cycled as long as there is a steady supply of ammonia for the bacteria colonies to feed on, right? So adding too few fish would shrink the colony, but too many could overwhelm the colony and lead to toxic water?

So, for a 30 gallon, how many fish per day/week?

Thanks,

Micah

Christian Patti

It really depends on the fish. You could probably add a school of barbs or tetras. But when you get into fish that are larger and produce more waste you need to add fish more slowly to let the bacteria catch up to the new load.

expansion5th

Thanks Christian - I was just in New London, New Hampshire over the weekend - beautiful this time of year!

I was thinking I'd start with a school of 6-8 tetras ... how soon after that can I add something else?

pepetj

Hi Micah, Welcome to fishlore:

If you did your fishless-cycle well (obtaining readings of 4 to 6ppm during the Ammonia spike), once your Nitrite spike fades down and Nitrates begin to rise, you do a water change (to remove Nitrates) and add your fish at once (all of them) as long as you don't push the limits in stocking your tank.

If you are going to overstock (wouldn't recommend it, but I confess I do it in some tanks), then do it slowly, adding fish every two to four weeks.

There could be exceptions for doing this, so far I recall these ones:
a) delicate (e.g. Angelfish) or likely disease-prone fish (e.g. Dwarf Gouramis) or just fish that come from different batches might require them or others passing quarantine first before going into their final home tank.
b) some fish you plan to keep must have a stable tank to survive (e.g. Otocynclus, Discus) and need to be added only when you are certain of your tank's stability.

In my experience, the likeliest worst case scenario, once cycled, is that your tank will go through a mini-cycle, meaning you will obtain readings of Nitrites (not a full blown spike). In that case you do daily partial water changes until your tank's bacterial colonies can handle the bio-load by themselves. This can take several days or, more commonly, several weeks.

I have only once experienced/handled a mini-cycle in a recently cycled tank, but it was due to an emergency (I had to put a 5" Oscar in a 29gal bow tank -which had six juvenile Convicts in it already, since the LFS couldn't keep her for me any longer). It was a lot of stress and a lot of work, but I fell for that particular Tiger Oscar -I wouldn't change her for no other, if you know what I mean.

What are you planning for stocking? There's a lot you can do in a 30gal tank!

Pepe
Santo Domingo

expansion5th

Thanks Pepe!

Actually a dwarf gourami was going to be my next addition after the tetra. This is the first I've heard of them being disease prone. Any recommendations in that regard?

30g is bigger than I was originally planning, it's just worked out this way and I'm still trying to figure out what to put in it. I know I want a khuli loach and probably some Corys. I'd like to keep african dwarf frogs but I'm nervous about them climbing out of the tank. I have a thing for balloon mollies but I know they do better in higher PH and even brackish water. I wanted silver dollars but I hear they will eat all of my plants.

Any suggestions?