Cycling Advice Needed

[NewBea]

Hi Everyone,

So based on the advice I got from helpful members on this site. I've got my API test kit and carried out 25% water changes in my tank every day then every 2 days. (just briefly the background: I had a tank for 2 months with plants and running filter however I didn't know that I had to add ammonia to start the cycle so when I got my fish I had to start a fish in cycle. 100L tank; 2 sailfin mollies, 4 mollies, 2 swordtail and a dozen or so molly babies which came around a day after we got the fish. Fish started behaving strangely: hiding and gasping for air - this is the point I started asking for advice)
I have been testing for about a week or so:
- PH constant at 7.6 (tested tapwater as well results the same)
- Ammonia was at 0.5 then 2 days later 0.25, 2 days later between 0 and 0.25 and now it looks we are either at 0 or just very slightly over. The colour is quite difficult to tell and the only scale available is 0, 0.25, 0.5 and so own.
- Nitrite was 0 all week
- Nitrate was 10 to start with, 2 days later 5 which remained the same for the rest of the week. Tested the tap water today and it showed 5.

My questions as follows:
- Shouldn't the nitrite levels be increasing as the ammonia goes down?
- Given that the tap water is measuring at 5 it's unlikely that I would be able to get it down to 0. Is it ok to have 5 for nitrate or shall I buy some products that reduces it to zero?
- Is the ph at 7.6 is at an acceptable level?
- Provided that I get the ammonia to 0 (and nitrite as well of course) how long do I need to keep it at that level before I can buy the next batch of fish?

By the way I'm really pleased as all the hard work of testing and waterchanging paid off - my fish seem to be in a really good spirit again - no hiding and happily swim around, they come to see me when I go up to the tank to check on them

Thanks for all the advice in advance.

 

[fluttermoth]

The nitrite should be increasing, yes, but it's quite common with fish-in cycles not to see it as the bacteria seem to grow at different rates with fish-in and fishless cycles.

Nitrate is fine at anything up to 40/60ppm, unless you have very sensitive fish, like discus or blue rams, although lower is better. Try and keep it at 20/25ppm with regular, weekly water changes

A pH of 7.6 is fine for most fish, including the ones you have; most livebearers prefer harder, alkaline water anyway.

When you've had zero results for both ammonia and nitrite for a week, without needing to do any water changes, you can add your next lot of fish; but no more than 50% of the amount you have now, so as not to put too much load on your bacteria, until they've multiplied enough to cope with the extra waste.

 

[NewBea]

Brilliant! Thanks very much for the info - you always give really good advice!
Yes I realised that the amount of fish we got first time around was a bit too much. We went by the advice from the shop (recommended between 5-10) and once I joined this site I learnt that it really should have been about 3-5. I will make sure next time I buy I go for around that number.