Hello there, I had a 25 liter fish tank for the last 5 months with 4 platys, 1 guppy and 6 red cherry shrimp and decided last Saturday to upgrade to give them a better quality of life, so I went to Pets At Home & purchased the 64 liter fish box and took it home very excited to see my fishy friends enjoying far more space, however being relatively new to fish keeping and having never intentionally cycled my first tank (I did not know what it was and it must have happened of it's own volition, as I put 2 platys in as soon as I bought it and they are still alive today). Anyway I purchased a big bag of the same substrate I used in my smaller tank and mixed it together with my old substrate as well as putting all plants and ornaments as well as my old filter (alongside the new one) into my new tank (I figured this would make the water quality the same as my old tank, yes I was VERY naive and have learned A LOT about cycling in the last week or so reading forums like this). Anyway day 2 in the new fish tank house: all 6 cherry shrimps dead. This was really upsetting as I had obviously not experienced any deaths thus far. Ever since then it has been just as depressing, the fish have spent the last week swimming at the top of the tank clearly trying to breathe, I have tried all sorts; after the shrimps died I did a 90% water change as a website recommended I try that, no change, I have been doing 20% water changes every day for a week and it seems to be getting worse, there is a horrific smell coming off it (can barely describe) and the water is cloudy white. The plants which had been thriving previously are falling apart, there seems to be a viscous layer on the top of the water despite my daily cleanings. I am reaching the end of my tether. All I wanted was to triple the space my fish had to make them happier and I seem to be making it worse with every move I make. I have read so much on the internet but from what I can tell it seems to be rhetoric, the whole "clean 20% a day" fish-in-cycle line. I do understand the whole cycling process now so please don't just repost what happens during cycling, I need to know what I can do to stop these poor fishies dying, also I dechlorinate my water using a chlorine control solution and use a "weekly cleaner" on all new water introduced to the tank, I have also tried turning down the temperature from 28 to 26 in the hopes that would increase the oxygen in the tank.
I will include a (depressing) picture below.
I will include a (depressing) picture below.