That is incredibly hard water. No mistake in measuring? These are readings in German degrees?

The usual hardy plants like Anubias, Microsorum, Valisneria should be able to grow well in such waters. To my knowledge Pogostemon helferi and Rotala ramosior will also prefer harder waters because they like calcium, although I don't know if they will do well in water like that.

For fish though... I honestly don't know. African cichlids will probably like your water???

I don't know of any good way of reducing KH other than mixing it with RO. To be honest, that's probably the safest way to do so.

 

My water is 8.2 pH, and also very hard. Guppies, turquoise rainbowfish, lemon tetras, serpae tetras, pristella tetras, Corydoras trilineatus, and pearl gouramis have all done well. I've tried several other species of cory, with mixed success. Black neon tetras did well for about three years, but have started to die off.

Crypts, hornwort, vallisneria, guppy grass, pearl weed, Mexican oak leaf, dwarf lettuce, bacopa, and probably a few others that I can't think of right now have also done well. Anacharis has too, but it's finicky about getting started.

Also, several years ago I got a beautiful clump of susswassertang from a hobbyist in another state. That beautiful clump just got smaller and smaller until I thought it was all dead, but months later, when I had forgot all about it, I started to see a few bits and pieces in the tank. After that it took off, and has now done well enough that I've sold a good bit.

 

The only way I know of reducing KH or GH is to dilute with RO water. It's usually easier to use the water you have if possible. From what ProudPapa said, you should be able to use yours. There will be some fish and plants that won't do well, but some will.

 

Thanks for the responses! I'll look to get some plants and fish that will do well in the water I have then.
Has anyone had any success with pH buffers to lower kH and pH with hard tap water?

That is incredibly hard water. No mistake in measuring? These are readings in German degrees?

The usual hardy plants like Anubias, Microsorum, Valisneria should be able to grow well in such waters. To my knowledge Pogostemon helferi and Rotala ramosior will also prefer harder waters because they like calcium, although I don't know if they will do well in water like that.

For fish though... I honestly don't know. African cichlids will probably like your water???

I don't know of any good way of reducing KH other than mixing it with RO. To be honest, that's probably the safest way to do so.

Don't think it was a mistake in the measuring, I used the NT labs test kit for it. Plus the API test strips were maxed out for gh and kh so I think its accurate.

 

Plus the API test strips were maxed out for gh and kh so I think its accurate.

Test strips are notoriously inaccurate - especially for hardness. A slight bit of humidity or temperature change can ruin them, unfortunately.

How fresh/new is your NT Labs test kit?

It's not unheard of for water in your region to be that hard but if I were in the same situation, I'd get a new, different brand of liquid test kit to verify. Or, if you receive your water from a public utility or company, check their website or give them a call to ask about water parameters.

What size aquarium do you plan to keep? If RO water isn't an option, maybe it'd still be reasonable to buy one of those 18/20 liter jugs of distilled water from a grocery or big box store and use it to dilute your water a bit. Depending upon tank size, of course.