RO or RO/DI?

Which one should I invest in? After countless trips to the LFS and the grocery dispenser its time to invest in one here at home.

 

I'd go RO/DI. It's just an RO unit with one or two cannisters od DI resin attached it. They are used as the final filter step. It will cost just a little more.

 

I 2nd the R/O DI, never cut back on water quality. If you do it only causes headaches with consistant algae growth.

If you check on ebay you can get some pretty good deals on new units with the di in the 10" containers instead of mounted above the R/O unit. That way is less leak prone. I would not suggest buying a used unit though, for what you would have to pay for it and then have to replace the filters you might as well have bought a new one.

 

Thanks for the quick responses. Any particular brand I should look for or avoid?

 

There are several RO/DI systems out there, I purchased the 75 gpd, 5 stage system from BRS...

Bulk Reef Supply - Bulk Reef Supply

 

RODI. Check out air, water, ice. They are 3reef sponsors too so mention 3reef 1000 times if you order from them!

 

Just another thought you might consider a 50GPD unit or higher over a 35GPD unit Some people feel that they dont produce water at a fast enough rate to make them happy. This is also effected by your water pressure. All of the rates produce quality water they just make it faster or slower.

 

i just got a RO/DI unit from bulk reef supply. Looks really nice, I haven't run it, I will say that because I am a LONG way from set up (I don't want to go into the shady ebay-er that has my money for a skimmer that I haven't seen).

Anyways the main point I wanted to make here is DON'T go with that cheapo ebay seller that's about $85 right now. Support one of the 3reef sponsors like Air,etc. but don't bother with that super cheap stuff.

Oh and if the core question is still ro or ro/di look at the numbers. Ro still usually leaves you with 60-100 in TDS

 

I don't even have a TDS that high before RO...

 

Horizontal DI is pretty much useless fairly quickly. Channeling will occur and the resins on the bottom will become exhausted so even though you have plenty of unspent resin, the water will take the path of least resistance and never touch them.

I personally prefer vertical separate filters for my anion and cation resins but even a mixed bed vertical filter is better than a horizontal one.