Looking for a good RO/DI unit

NWhoric · 10-03-2007, 12:12 PM

I am looking into gettin an RO/DI unit and have been doing some research. my only concern is the amount of waster water and i have read something on this forum about pumps that push the waste water back through the filter again and decrease waste by 80%. wondering how many people have had success with that and what would be a good unit for a first time user. i currently have a 40 gal, 125 gal salt tanks set up and a 100 gal and maybe a 220 in the next few months. it all depends on the cash flow... thanks for the help

Loverotties · 10-03-2007, 12:51 PM

Check e-bay!alot of people buy them there.

NWhoric · 10-03-2007, 02:37 PM

whats a good name/brand?

Mizer67 · 10-03-2007, 05:36 PM

A couple of things to watch (that I wish I knew before I ordered off ebay). A vertical DI canister is better than a horizontal one (vertical ones look like the other filter cannisters, horizontal are usually piggy backed on the RO filter housing). The horizontal is worse about channeling and allowing the water to bypass rather than flow through the DI resin.
100 gpd gets to 100gpd by actually being slightly less efficient that the 75gpd. I think I remember something like 94% vs 99% but can't swear to it. Even with a 220, 75 gpd should handle water changes just fine and you really should only need to make 220gals the first time.
The only waste reduction scheme I know of is using a second RO membrane and re-filtering the waste through that. Definitely helps waste water, but you pay more in upfront and membrane change costs (which aren't as frequent as the pre-filter cartridges). I am happy with my unit, but wish I had done a bit more research.
Other nice to have's are inline TDS and pressure gauges. Not essential but nice.
The Filter Guys and Melev's Reef (over on the "other" reef bulletin board) have good reps. I haven't looked to our sponsor list re: RODI stuff yet. HTH.

Geoff · 10-03-2007, 10:03 PM

i like my www.airwaterice.com typhoon.

booster pumps do help a lot with cutting down on the waste water. also using your waste water to water indoor plants is a good use of it.

G~

NWhoric · 10-03-2007, 10:58 PM

Quote:

Originally Posted by Geoff

i like my www.airwaterice.com typhoon.

booster pumps do help a lot with cutting down on the waste water. also using your waste water to water indoor plants is a good use of it.

G~

how do the permeate pumps work? i just noticed that they are nonelectric. what is ur opinion on uv sterlizers?

Geoff · 10-04-2007, 10:29 AM

a UV sterilizer for which, the tank or the water source?

G~

NWhoric · 10-04-2007, 12:02 PM

Quote:

Originally Posted by Geoff

a UV sterilizer for which, the tank or the water source?

G~

opps

tank. the guy i bought the 125 off of had one on it but he wanted to keep it. but once i moved the tank and had it set up at my house i noticed the next day that the fish had ick like symptoms. i wasnt able to treat it fast enough and lost a few of the fish. but that didnt upset me to much (yes i was disapointed) because i only paid $200 for about $2500 worth of stuff. that just made me wonder how well they work for stuff like that.... i was lookin at the typhoon ro/di units. what do u think about gettin the psi gauge, inline tds, and the handheald tds meter? the typhon III 75 gpd is the one im probably goina get.

shepbird07 · 10-08-2007, 04:08 PM

Has anyone had a problem with the ro/d? .I have about 300 gallons on my new system and it now went from 0 ppm to 42 ppm. I can't figure out what has cause this. Could it be a bad membrane or a bad di or both? I now have a out break of brown stuff in both my reef tanks. Anyone have any idea what this is?

Thanks...

wharyat · 10-08-2007, 04:25 PM

Quote:

Originally Posted by shepbird07

Has anyone had a problem with there airwaterice typoon III? I got it local at a reef store .I have about 300 gallons on my new system and it now went from 0 ppm to 42 ppm. I can't figure out what has cause this. Could it be a bad membrane or a bad di or both? I now have a out break of brown stuff in both my reef tanks. Anyone have any idea what this is?

Thanks...

Most likely you need to change out your DI resin.

I change out my DI resin whenever I have over 0ppm tds. I normally get 500 gallons out of a fresh DI resin change. Your RO membrane should last at least 3 years with proper care and maintenance.

Geoff · 10-08-2007, 08:54 PM

Quote:

Originally Posted by NWhoric

opps

tank. the guy i bought the 125 off of had one on it but he wanted to keep it. but once i moved the tank and had it set up at my house i noticed the next day that the fish had ick like symptoms. i wasnt able to treat it fast enough and lost a few of the fish. but that didnt upset me to much (yes i was disapointed) because i only paid $200 for about $2500 worth of stuff. that just made me wonder how well they work for stuff like that.... i was lookin at the typhoon ro/di units. what do u think about gettin the psi gauge, inline tds, and the handheald tds meter? the typhon III 75 gpd is the one im probably goina get.

sorry, i missed the update. the 75gpd membrane is the good one. the 100gpd one is not as good at rejecting impurities.

UV's are next to useless when it comes to controlling parasites. they only way a parasite is going to be killed by the UV is if it goes through it. with the amount of flow most UV's have and where they are located in the system it is unlikely any parasite is going to go through it. now, i do think UV's can be extremely usefull on a reef system, but it is not where you would think it would be. if you have a good UV unit. the best place to put a UV sterilizer is directly in front of a protein skimmer. if you can get it on the input for the infeed pump for the skimmer even better. that way anything that is killed by the UV is immediately removed by the skimmer. that way dead matter is not allowed to settle into the tank and rot. causing algae problems. the UV is also very good at breaking down some organics into smaller more easily skimmed bits. another reason to put the UV just before the skimmer.

G~

Hop · 10-08-2007, 09:15 PM

Quote:

Originally Posted by NWhoric

I am looking into gettin an RO/DI unit and have been doing some research. my only concern is the amount of waster water and i have read something on this forum about pumps that push the waste water back through the filter again and decrease waste by 80%.

I have yet to see any thing that would have 80% decrease in rejection. A booster pump is used if you don't have enough psi at the membrane.

With that said, one thing that can help is to run a piggy-back unit on your RO/DI unit. It's another membrane and housing that is fed from the waste line of your unit. Therefor, if you had a 4:1 rejection rate, you are dropping it by a degree by using more of the waste to make good water.

There are a few companies that offer a unit with a piggyback already installed, such as spectrapure and the filter guys, or you can buy and install one yourself for about and extra $100. You also make RO/DI water twice as fast, so 2 75gpd units would get you 150 gpd, so you actually have your unit on less frequent

NWhoric · 10-09-2007, 12:56 AM

$ 199.00 - OCEAN REEF + 1 FIVE STAGE 75 GPD RO/DI from http://www.thefilterguys.biz/ro_di_systems.htm

what do u think of this one? hopefully goina purchase one in the next few weeks. dont really have time right now to hook it up with school and everythin. thanks for the help

Hop · 10-09-2007, 01:01 AM

It's a good unit. My neighbor bought one and really likes it. For $40 more, you could grab the piggy back unit if you are still worried about waste water

NWhoric · 10-09-2007, 11:55 AM

well how much waste would i be lookin at without one? i mean a 50 gal trash can last me like 3 weeks cause i loose so much water with evap that i dont do that many water changes im puttin around 5 gals a week in my 40 and around the same in my 125 (125 less cause its in the cool basement and has a glass top, the 40 will be joining it soon to makes my room way to hot and humid)