HELP on upgraded tank please

[GoldenPlecTony]

Hello people

Ive managed to get a 90L tank (Second hand) that has been set up for sometime. Is the best way to set the second hand tank up at my home filling it totally with tap water (Including tap safe)? After a few days with using the used filter which came with it test everything in the water and slowly add the fish over a few weeks providing all is well? Im having a battle with my current tank to get the ammonia down due to adding the fish too quick and do I **** want to make the same mistake twice.

We have 4 Guppies, 6 neons, 2 corys, 1 Fetherfyn Syno, 3 Mollies, 1 Betta. (Hense the upgrade)


PS... I didnt want to add any of my current tank water to the upgraded tank as the ammonia is high etc... Or is this best? My ammonia is just over 4.0 at the mo. Currently doing daily 25% water changes to battle this mofo!

 

[RabiedRooster]

What you could do is use the water with the ammonia to cycle the new tank without adding any new fish. This would be OK to do but by the sounds of it your new tank came with a mature filter? If this is the case you would need to stock the tank as you suggested or do the above suggestion asap to keep the filter bacteria alive. Either way it should be OK. Do you find your betta and your guppies OK together as the betta may find then too similar to itself and attack them?

 

[GoldenPlecTony]

They were ok for the first 3 weeks but now some of the guppies have chunks out of their tail! Hopefully with the slightly larger tank they can keep out of each others way, I'm going to monitor it over the next week and if things dont improve I have a tank I could move the guppies to ... Thanks for the advice I will ask the person I am purchasing off to not clean the filter out.