Don't do it... slow and steady is the way. You can use pure RO to top up evaporated water, for everything else, it needs to be remineralized (I believe that's the term used) in some way. You can mix RO and tap water when doing water changes, but I wouldn't bother just for the sake of keeping a lower TDS for the shrimp. I've had fish and shrimp with TDS above 400 and they didn't really bother with it.If I were to do water changes with (pure) RO from now on, will I minimise the chance of diatoms?
Sorry, I don't know if I'm understanding what you mean correctly... but if you're doing water changes with RO only, you are diluting whatever there is in the tank already, but you'll be changing the water chemistry in tank a bit too quickly for my liking. Almost nothing in this hobby comes the "quick and easy" way.I’m effectively cutting the RO with the existing tap water, right?
I've been in your place before mixing RO with tap water to have lower TDS (my tap water has around 300)... then someone here told me there was no point, I gave up and it made absolutely no difference. I had a tank with shrimp running with TDS over 400 not that long ago and they still bred like crazy.Re:TDS is it not good practice to match it to what they’re already used to?
True. If the water is similar in both tanks (TDS, other params, temperature, etc) you wouldn't even need to acclimate. Once in a while I move shrimp between tanks, and since I keep all my tanks the same way I don't even to acclimate them.Understood but surely my shrimp will better withstand the acclimatisation if the TDS is similar in each tank? I wouldn't like to put them from 200 into 350+. Isn't it just something else that can go wrong?
I suppose I could just start water changes in the existing shrimp tank with tap...