I'm not all that sure that pure RO or Zerowater is all that healthy to drink all the time as when it is filtered it removes everything, good and bad but I could be wrong as I am not known for my healthy eating........... Even for the shrimps you need to add back the good bits with GH+ (or GH/KH+)?
I had a quick look and most of the range is available from walmart and the prices are the same (near enough) to the manufacturers website!
Bear in mind that water going through the filter of this size is a SLOW business so if you are going to multi-use it, or do many litres each time you are best to get a largish one as kms states, so you can just fill the top bit and leave it to do its thing! If you do get a larger one you may also get a TDS meter (hand as a spare). You need to change the filter before it gets to TDS 006 and in my experience that happens suddenly so as soon as you get ANY TDS you will need to keep a closer eye on it (ie I probably get 90L at 000, then 6L at 001, then 4L at 002 and then TDS goes up each litre - hope that makes sense?).
What scares me is that I’ve been drinking and feeding my children ‘filtered water’ with TDS 160+ for years. I thought the filter I had was filtering out heavy metals (lead, chromium). Maybe so, I actually sending samples for free water quality testing.
It seems like the zero filter is the way to go.
Rain water is also brilliant for the shrimp. I’m not sure how polluted it is where I am. I have rain barrels but I also dose with mosquito dunks which I fear are toxic to shrimp.
I definitely want to get into crystal and bee shrimp and be healthier.
Like@sdlTBfanUK, which he recommended the zerowater to me, I got the table top 23 cup version, and recently I got a jug 10 cup version, the jug version works out cheaper than than just getting the filter from where I live. It's a must is a RO system cost too much.
You can also consider the Oceanfree hydra in tank or canister filter, they do improve the water quality, it all depends on if you can obtain one, they have a large range.
Buy these items for a bit over $200:
and ask them to switch out the carbon block for a chloramine block
and also ask them if you are missing any minor parts like fittings.
Or piece together a similar system on Amazon for a little bit less.
U got to pay to play if you want clean water.
The bonus is that you can drink this water yourself.