Altering one water parameter without effecting others

[El chapo]

I've got to lower water hardness from 200 ppm to 100-150 ppm without changing ph and was wondering if anyone knew any tricks

 

[GaryE]

Some more info would help get an answer.
Why?
What fish?
What parameters?

 

[JuiceBox52]

Some more info would help get an answer.
Why?
What fish?
What parameters?

What he said

 

[Back in the fold]

I cut my hard water with Reverse Osmosis water to get the hardness lower. The pH stays the same.
And just as an aside to other forum members. Do you know who El Chapo is ? I gave him a good answer. I do not want El Chapo angry with me. A word to the wise.

 

[El chapo]

Some more info would help get an answer.
Why?
What fish?
What parameters?

Water is to hard everything else is within range
Angelfish/scissortail rasbora/Kuhli loach/Cory
Current parameters are nitrates-60 ppm nitrites-0 ppm hardness-200 ppm kh-20 ppm ph-6.5

 

[Byron]

I do not consider the fish mentioned will have any issues with the current parameters--parameters referring only to GH, KH, pH (and temperature).

Nitrates at 60ppm is a problem for all fish. Are these occurring within the tank's biological system, or are some entering with the source water? These are two different issues requiring different solutions depending.

 

[El chapo]

I do not consider the fish mentioned will have any issues with the current parameters--parameters referring only to GH, KH, pH (and temperature).

Nitrates at 60ppm is a problem for all fish. Are these occurring within the tank's biological system, or are some entering with the source water? These are two different issues requiring different solutions depending.

The nitrates are still a little high from an ammonia spike that occurred last month

 

[Byron]

The nitrates are still a little high from an ammonia spike that occurred last month

If it were me, I would do a few water changes (additional to the regular) to get nitrates as low as possible. These have what is best considered to be a weakening effect upon all fish, some more than others, and depending upon the level and the duration. Cichlids (like the angelfish of course) are one group of fish that have problems at 20 ppm.

 

[itiwhetu]

The nitrates are your main problem, you need to figure out how to lower them to near zero and then see what your other parameters are doing.