Hi all.

I am new to the form and new to Discus keeping. I have had Malawi Chiclids for over 10 years and thought it is time for a change and moved to Discus. I got rid of all my fish cleaned the tank and gravel out to prepare the tank for my discus. I installed a 3 stage RO system. I filled my 300 litre tank with 75% ro water and 25 % treated tap water and ran it for 8 weeks. I have an external Fluval 405 filetr and to promote bacteria I was adding a littel food on a daily basis.
I populated my tank after 8 weeks with 20. Neon Tetras, 15 Black Tetra 5 ruby nose tetras, 2 rainbow gramis and 4 Rams. After week 12 Introduces my discus and my water parameters were:
Ph7.5
Amonia 0
Nitrate- 5 mg/L
Nitrite 0
KH 70
GH 100
TDS 85
Temp 29-31c
Now the problem strated when Ick hit my Rams and started spreeading. I removed the carbon from my filters and treated my tank with ick medicine. After a week I added core salt and increased the temprature to 31 degrees celicius. It has been two weeks adn the ick has gone but my TDS is stll at 580 even afetr daily water changes at 60 litres a day(85% RO ansd 15% tap). My parameters now are
Ph7.5
Amonia 0
Nitrate- 20 mg/L
Nitrite 0
KH 70
GH 100
TDS 580
Temp 29-31c
Waht can I do to bring down my TDS? Are all other parameters OK?