Can I go and get more fish??

Here's what I have so far -

4 male guppies
3 cherry barbs
3 corys
2 BN's
2 black and white mollies

Can I have any more do you think? Also, my son says that having all male guppies and mollies could cause problems when the fish get a bit older - is that right?

Possibly. They're both livebearer species and all that "maleness" might cause problems. IME Male mollies get bolshy anyway as they age. I'd add a few more cherry barbs as they're better in larger groups. Ditto for the cories. Maybe have 6 of each in total.

Dont know if I should have started another post with this Mary but I just wanted to say . I followed your advice and went and got 3 more cherry barbs, all females I think, and I also got 3 more corys too. They looks so cute because they all seem to hang around togethjer at the minute . I am going to update my signature now!

Well done elj. It's great when we hear of someone going and finishing the cycle and then getting fish

Now the rot sets in elj. The next thing is that you will think your tank is too small, or you want cichlid only tank (what's happened to munchycarrot by the way??? Haven't heard from her for ages?), and then the dreaded MTS sets in and you are DOOOMED!!