thanks for trying to help me twinkles,
I have a CF1200 filter for the tank, 2 air stones, 2 peices of driftwood and just normal aqurium stones, its got java fern and ambula plants and a few other low light plants. Those are the only items in the tank.
The tank has roughly 40 adult fancy guppies, 8 baby BN (1 -3cm ea) and 2 harlequen rasboras.
All the guppie babys have no troubles, never see them dead or look like they are dying, the BN also are going strong and have no signs of fin rot or dying.
I did a test the day before putting in the new lot of guppies and ammonia, nitrate and nitrite were all 0, ph of the top of my head was around 6. The temp in the water is about 25.2 atm and is normally never lower than 25 or higher than 26.
This tank has been setup since january, originally had 1 breeding pair of BN, 6 neons and 6 rasboras, never had any issues, no deaths, they servived the whole tanks cycle and never had any issues untill 3 weeks ago when i did the swap.
My 300L tank down stairs have had the guppies in it for the past 4-5 weeks , the reason i had to swap them round was because i was getting some cichlids and they needed the bigger tank.
So 2 days before my chichlids came the heater issue took place in the big tank with the guppies and since then all my fish have just gone down hill.
So in my cycled tank upstairs i just keep loosing adult guppies.