Could anybody share own experience how to avoid water parameter fluctuations while the water changing with pure RO water? I’m always afraid to add pure RO to the tank directly and mixed with tap water (4:1). But some people do. GH falling maybe is not so harmful as pH or KH. And increasing KH with baking soda (in few minutes) may kill all flesh.

Thanks

I think the only way to avoid fluctuations is by changing it with the same water every time. For instance, if you always add 1:4 RO/tap water, what you take out will always be the same as what you put in. Same with adding things that increase GH or KH. If you are using RO for the first time in a water change, you would have to do it gradually (maybe 10% at a time). Same thing with adding baking soda or GH booster if you haven't already been adding it, a little at a time.

My purpose is to avoid using tap water and switching to RO+GH/KH booster. My desirable level KH=4dKH. But RO = 0dKH. To replace 50% by osmosis (and even more) I will have 2dKH (or less) so I need to increase KH from 2dKH to 4 dKH in a very brief spell. If I do that it may be harmful. Mixing osmosis and GH/KH booster out of tank is not a good idea as well, because one dissolves slowly and I need another volume I don’t have (and don’t want). That’s why I’m looking for an advice.

I'd use less KH/GH.

Shoot for 2 degrees or so of each.

You do not need 4 except if want some rift species etc.
Most all other fish can do well at lower GH/KH.
Same for plants.
I'd blend with the tap personally.
Most clients I deal with all do this.

If you are weird about tap, just run it through a carbon prefilter, no need to go all RO.

Why take it out.......... only to add it back?

Regards,
Tom Barr

Is that enough for shrimps?

Check out ADA's tanks

Regards,
Tom Barr

QUOTE FROM ADA EUROPE:

ADA All Rights reserved. Vendita Prodotti per Acquari d'acqua dolce - Takashi Amano NATURAQUARIUM

"As AQUA SOIL greatly reduces the pH, GH and KH values, it is important to use also tap water during the layout and the above-mentioned partial changes of water (around 30% every week). Hardness of tap water is variable. Advisable values are 3-4 KH and 6-8 GH. For example, we advise using 50% tap water, with KH 8-10 and GH 15-20, with 50% osmosis water. After about ten water changes, maintain a ratio of osmosis to tap water of 4 to 1. "

Look at ADA's tanks, not advice from ADA Europe.
GH/KH's are about 2, plenty of folks in the SF Bay and is Sac have shrimp and low KH/GH.

Regards,
Tom Barr