RO/DI system advice

[Utah Fatman]

I'm looking into adding a RO/DI unit to my set up so I don't have to chase water all the time. I'm looking at 75-90 gallon four stage models. I see everyone is advertising five stage models. What am I getting with a five stage that makes it worth the extra money? I'll install a pressure gauge and a TDS meter once I get the unit.

What makes offer the best value?

Thanks,
Fat

[bertoni]

The 5-stage models I saw with a quick look have two carbon phases after the sediment filter, with decreasing pore size. That might be good for removing large amounts of chlorine, but I had fine results with a 4-stage unit. A 5-stage unit with two DI phases might be useful to help keep water quality up or decrease some maintenance worries. If you could point to a few models, we might be able to say more.

I haven't bought a filter for a long time now, so I don't know much about the various offerings. I'd be sure to get a unit with quality parts. Some products have been reported to be fairly flimsy.

[Utah Fatman]

I'm looking at a SpectraPure RODI-90 model. Four stages and DI.

[Randy Holmes-Farley]

My current system from Spectrapure has sediment, carbon, RO, and then two DI cartridges in series. It also has two dual inline TDS meters, measuring tap, RO, after DI 1 and after DI 2. I think that is an excellent setup. It allows you to use the DI cartridges more fully without any production of nonzero TDS water. I do not feel a need for any extra sediment or carbon cartridges with my water.

[Utah Fatman]

Thanks for the information. I'll order today.

[Jonviviano]

Thanks for the information. I'll order today.

I recently received my 5 stage unit from eBay. $95 dollars shipped. Still reading 0 tds...

[bamf25]

I have the five stage from BRS with the added watersaver feature. Works great and good price.

[spankdog]

I am using the spectrapure 90GPD model and it works great. I've been getting 0 TDS for a year now

[Plato]

Spectrapure MaxiCap

[fishresponse]

My current system from Spectrapure has sediment, carbon, RO, and then two DI cartridges in series. It also has two dual inline TDS meters, measuring tap, RO, after DI 1 and after DI 2. I think that is an excellent setup. It allows you to use the DI cartridges more fully without any production of nonzero TDS water. I do not feel a need for any extra sediment or carbon cartridges with my water.

I'm thinking of adding a 5th stage (DI). Do you use different quality DI filters? Or are they the same?

[Randy Holmes-Farley]

Spectrapure has a specific recommendation (silica buster second, for example), and that seems like a very good plan, but I've most recently been packing my own with BRS ion exchange resin because it costs a lot less and is adequate for me.

[reefkeeper429]

i just got my pure water club 6 stage with dual outputs tank and faucet for 145 great setup

[Utah Fatman]

It came this morning and I set it up on my lunch hour. Took a whole 10 minutes. Let it run a bit then adjusted the rejection rate to factory recommendations. After running a little water I started to collect it. 0 TDS out of the DI. My house water is 284 TDS. Tonight I picked up some ball valves and a T and put them in ahead of the DI unit, so now I can cycle it to run off the first few gallons of high TDS as the system starts. I am getting 4 PPM TDS out of the RO units and it sure makes some sweet tasting drinking water.

Thanks for all the input on this purchase. I'm very happy with it and am currently producing water for my first tank.

[bertoni]

You're welcome! I'm glad to hear that the unit is working well!

[fishresponse]

After checking my tap in the kitchen puts out 300+ TDS. This could be one reason why my DI output is only at 9. Still planning on the 5th stage DI and getting spectrapure's silica buster filter. Hopefully that will get me down to 0 TDS.

[Plato]

After checking my tap in the kitchen puts out 300+ TDS. This could be one reason why my DI output is only at 9. Still planning on the 5th stage DI and getting spectrapure's silica buster filter. Hopefully that will get me down to 0 TDS.

What is the TDS on the RO before the DI and are you on city or well water. What size membrane / brand do you use and what is the pressure on your system. I've got Dow Film Tech and on city water with a booster pump @ 80psi with 300 tds I got 2 out of the RO.

[Randy Holmes-Farley]

That sounds like a good choice.

Was the TDS ever 0 ppm? Maybe it is becoming depleted?

[fishresponse]

What is the TDS on the RO before the DI and are you on city or well water. What size membrane / brand do you use and what is the pressure on your system. I've got Dow Film Tech and on city water with a booster pump @ 80psi with 300 tds I got 2 out of the RO.

Brand new sediment filter and carbon filter. the TFC is a 35 GPD Kent Marine Hi-S membrane, and Kent Marine's Hi-S DI cartridge.

I've used these in the past with no problems but that was a different part of the United States. I'm back in the Midwest and the water is VERY hard. I'm on the city line but could be the hard water that's causing my filters to not perform at their potential.

[Plato]

fishresponse what is the tds of the RO before the DI. I also agree with Randy that you Di may be depleted. If your getting 300 tdi in at 98% rejection you should have 6 tdi out and the DI should scrub that to 0 with no problem.

[fishresponse]

Haven't checked that yet. The DI is a brand new cartridge so I'm assuming it's not exhausted and it has only been online making water for about 2 months. I was thinking that there could be a leak within the DI or another stage of the filtration letting tap water sneak by but this is just a theory.

[fishresponse]

Late update but this past weekend I installed a 5th stage DI and another inline TDS meter. TDS before 1st DI is 9. After 5th stage (2nd DI) I'm getting 0 TDS. Note - I added the silica buster micron sediment filter and spectrapure's silica DI cartridge. It did the trick!!

[Randy Holmes-Farley]

Sounds good!

Happy Reefing. :)