So then is it bad to fill up store water jugs with RO/DI and let them sit for a few days in your house ? I only use a Aquarium Pharmaceuticals Tap Water Filter so I fill 4-5 5L jugs about once a weak to make fresh water and fill my ATO. The bottles I use are originally from save-on foods. Could the plastic possibly be leaching ? I haven't seen any problems but is the possibility there ?

Yah they could be but if they are well used they should be OK the bottles I had a problem with were brand new and that was where the problem was. I myself for drinking water dont trust plastics any more with all the chemicals that can leech into the water.

Good to know. thanks for the helpful tip :smile:

I've heard of magnesium being used as well because it is far down at the bottom right of the redox table too (Strong RA)... If thats the case - guess the water might be GREAT for the tanks too eh? Haha. :lol: Everyone wants good Mg+ in the water!
(Actually now that I think about it, Magnesium is even better than zinc, its lower on the table)

That works until the beneficial magnesium gets to the RO membrane, whose job it is to remove any solids, including the beneficial ones... My source/tap water has fairly good calcium and not bad magnesium levels. I worked with it for quite a while, but am glad I went to RO/DI recently for my system, I can see the improvement after three water changes. Too bad there isn't a way to extract all the good stuff before the RO takes most of it out, well, there probably is, but I reckon you'd need quite a chem lab to make it happen.

Thanks for all your help. But I hope you can help me now, I found a small stumbling block...
Most of units I am looking at are 15-18" tall and I only have 11"-12" max height to work in under my sink.
Does anyone know of any units that are about 10-11" tall and can put out 25-55gpd?

I bought the aquaticlife power unit works great...what I like about it everything is enclosed and you change the filters from the top. But it’s around 15” tall however it stands on its own base so you don’t have to mount it.

Most of the units are as tall as you say. The inside filter is a standard 10 in tall.
Just measured my individual filter unit, it is 11.75" tall. If you have 12" in you could still mount the unit. Would have to mount the ro membrane, which is atop of the filter unit, separetly somewhere else, just have to plumb it in with longer hoses. And the bracket that mounts the filters, just have to turn the bracket from this: L to this: 7
A seven does not make an upside down L but you know what I mean

Great ideas from hillegom. Just because the units come assembled on brackets etc, doesn't mean you can't get creative in how you wish to mount the assembly. If you get extra tubing and fittings, you can disassemble the whole works, reassemble without the brackets and stand the filters on the floor. Just need to have something for around the base of each cartridge to keep it from falling over.

The measurement of my BWI SR-1 unit, standard 10" transparent containers, is pretty close to 12" from top to bottom without the bracket though, not much room to manoeuver. You could always build a small wooden rack to mount them at a slight angle sitting on the floor, although not too far from the vertical as I don't know how that would affect performance. The RO housing is mounted horizontally anyway. Might seem like a lot of trouble, but by getting standard size cartridges, it's far easier to source replacement filters. When you buy smaller, custom and less common units, you're at the mercy of the OEM's filter format and they often crank up the price because there's no alternative when it comes to filter replacement.

Found a better solution - use a portable unit. Bulk reef supply has some that just hook up to the faucet and I can disconnect and store it when it is not being used.
Without all this discussion I would have never found a solution - Thank you to all!