RO units: what's desirable/undesirable in one, what's a good gallons per day rate etc

Akeath

I'm thinking about eventually getting a Reverse Osmosis unit. I want it to mix with my tap water in my 75 gallon freshwater tank; the tap water is at least 8.6 pH and 10 dGH. I want to get the water in my tank down to 6.5-6.9 pH (there is some bogwood in my tank too, which helps slightly). However, I'm not sure what to look for in a RO unit, I have no idea what is necessary, desirable, or just fancy. Could someone please help me? Also, is there any way I can get a rough idea of what parts of RO water I'd need per part of tap water? I'm very new to the idea of an RO unit.

Evan

first off you need to figure out how much water you will need per day and go from there if you only have one 75gallon tank I would say a 50gallon per day unit would be fine and when you get more tanks and have a need for more water than all you do is get a bigger membrane so instead of your 50gallon per day unit it would be a 100 gallon per day or what ever membrabe size you choose and will fit in the housing. the first cost of the r/o unit is the most and after that making more water gets much cheaper. as far as mixiing the water with tap to get it in the range you want all depends on what kind of fish you want to keep. for me its angels my tap is 8.0ph and 400ppm on the hardness thats not really bad for angels but lowering the hardness helps with the eggs hatching out better for me and spawning so I use it. what I do is use 75gallons of r/o ph6 and hardness 15ppm and mix 25gallons tap 400ppm and I end up with 100ppm which works out great, and I test all this with a hardness pen which are cheap and really help. here is a pic of mine its a 225 gallon a day unit it is about as bare bones as it gets but it gets the job done. pm me and I will sent you some info on where I got mine and I know they have ones that are under 100 bucks for a 50gpd.