Problems with KH & GH

[Rushfreek]

Hi
I have left my tank without fish stock for about 2 months, as I lost my group of Mickey Mouse Platies due to an accident by a family member whilst I was in hospital.
I use RODI water with new replacement stage 4 equipment.
My testing showed that PH was 8.0, but KH was 12 and GH was 15.
Should I be worried by the KH & GH figures?
How can I reduce both figures without crashing my PH?
I use Dennerle Shrimp King Shrimp Salt KH plus & GH plus to remineralize my RODI water.
Unfortunately, I have confused myself silly, via YouTube and other advise, so I would like to know what I should do before I consider adding Shrimp or Chilli Rasbora?
1. Carry on using my current remineralize regime, or change to what?
2. Using water softener pillows or what type of buffer to lower both.
3. Any other advise, would be really gratefully receive.

Please help.
Confused from Norfolk

 

[Aiken Drum]

Your RO/DI should be coming out of the filter with pretty much zero KH and GH, and a neutral pH of 7. The remineralising salt is then adding back hardness to whatever you want it, which will in turn effect the pH.

If your parameters are KH 12, GH 15 and pH of 8 then that is from however much remineralising salt you are adding. If you want lower numbers use less salt, if you want higher numbers use more salt. Starting with RO/DI you can tailer your parameters to whatever you want. Your product should come with instructions on how much to add to elevate your hardness numbers by specific amounts.

It's kind of pointless to add remineralising salts to elevate parameters and then add softening products to lower them. Just add enough remineralising salt to bring the parameters to what you want.

To start with, assuming you want to lower the values, just do water changes with the RI/DI without remineralising salt until the parameter lower to what you want. Then figure out how much salt to add to your water change water to maintain that level.

 

[BBradbury]

Hello. Have you tried not worrying about the chemistry of your tap water? I know this may sound too easy, but by simply removing and replacing half the tank water every few days, you can ensure your fish have a balanced water chemistry. A balanced water chemistry is more important than trying to establish and then maintaining a particular chemistry. As for the use of aquarium or other salts, you shouldn't need it as long as you maintain a sound water change routine. There are other, general maintenance steps that can be done less often, like water testing and filter cleaning as long as you're following an aggressive water change routine.

B