ro/di system

[BuckeyeHydro]

i'm looking to buy a ro/di system. i have a 75 fowlr and starting a 125 gallon tank i plan on drilling the back. i don't think i need a big system. how much is enough and whats the big difference between 3 stage and 4 stage systems. i have a couple other tanks and know it would be cheaper in buying a ro system. any advice will help me.

Thanks for the support folks!

Paul - to answer your original question - Even with your soon to be 200 gallons in tanks, you'll be OK with a 75 gpd RODI, but you'll probably want to have some storage capacity for the DI water. This doesn't need to be anything more elaborate than a Brute trashcan with lid. Size it to hold about 1.5 times your weekly topoff water demand.

Now - as to the number of stages - think of a 4 stage RODI as the default. In other words, go with a 4 stage rodi unless you have some specific water quality issues you're dealing with (e.g., chloramines or high sediment loads). Don't fall into the trap of thinking "more stages = better filtration." Not true.

Three stage systems you see are probably:
sediment filter-> carbon filter-> RO membrane
So these are RO systems rather than RODI systems

Four stage RODI systems will be configured like this:
sediment filter-> carbon filter-> RO membrane-> DI resin
and will look something like this:


Russ