New Ro/DI Unit

[joeyhatch11]

Quit question, just set up my new system this morning and seems Im getting a 3/1 ratio of waste water to good water. Was wondering if I could use a "T" harness and simply loop my membrane waste water into the blue line going to the DI section so Im not wasting anything. Now I do understand by doing this I will be taking the life out of the DI portion but being that the water is going through 2 other filters before this stage I dont think it would be that bad. Thoughts please. I just can't see having that much waste water go down the drain.

 

[joeyhatch11]

Bump!! Lol

 

[jpelzer]

If you do that there's no point to having the membrane. Best use for waste water is for clothes washing or garden watering... Just need a place to store it.

 

[downbeach]

Yeah, you're just bypassing the membrane, that way. The membrane is realy the workhorse to the system, with the sediment and carbon block there to lengthen the life of the membrane by prefiltering the raw water. The DI resin is really just to polish off the small amount of TDS that make it through the membrane. So, you could just bypass the membrane altogether, but you'll probably be replacing the DI resin each week. At $13.00 a refill/$52.00 a month...not a good idea.

 

[adesimone1]

+1 Jim

 

[jgraz]

Another thought is to purchase a second membrane. I know BRS sells a kit to add it. Supposedly this brings your ratio down to almost 1:1 especially if your using a pump.

 

[downbeach]

Here's the kit w / video(runs slow):

http://www.bulkreefsupply.com/brs-150-gpd-water-saver-upgrade-kit.html

Although you'll need a minimum of 65psi to make this function properly, or buy a booster pump.

 

[joeyhatch11]

Thank you guys for the replies. Ill be looking at the extra membrane kit next.

 

[jgraz]

I've been wanting to do it for a while. I have the housing just need the connectors and membrane. I've read that making water this way is very fast. But the pump is pretty much a must.

 

[joeyhatch11]

Yeah that's what Im finding out about now. This next step is going to cost at least $175+ between a pump and another membrane kit. Here are my thoughts on this. Before this RO/D system,I I was simply running a DI only system, one of those set-ups that have about 3in of carbon, 3 filter pads and then the DI. With that system I was making 60-80 gallons depending on the TDS of the water on different days. Plus I was only making 15 gallons at a time. Im really curious to see what this system will produce without a membrane kicking out waste water. With a full 3 stage system Id like to think I could get 200 gallons before the filters needed to be replaced. Even then from BRS its only $30 with shipping for the replacement kit. If this system could make 200 gallons that would last me damn near 5 months, I only use maybe 40 gallons a month. Thoughts on doing this?

 

[redfishbluefish]

If you wish to run DI only, I would highly recommend you look into a Kati-Ani system. It is basically the same thing as a DI unit, with the exception that the two exchange resins are already separated, making regeneration easy. Oh, and it's also a whole bunch bigger than a little DI unit. Once the Kati Ani is exhausted, you simply regenerate the resin using two simply chemicals. It would be way more cost effective over purchasing a ton of DI resin from BRS.

So you get no waste water.....however you need to regenerate frequently.


HERE's a link.

 

[joeyhatch11]

I dont want to go DI only now that I have the RO/DI. I just can't see running this system with all the waste water it produces. So Im going to take the membrane out and keep track of how many gallons I'm able to make before everything gets exhausted. If I can get a good amount of gallons out of it then I'll run it like that, if not I'll be forced to run a second membrane and get a pump. But that'll be later down the road when I can afford all those extras.

 

[joeyhatch11]

Well even with the membrane hooked up and having this system running for 45 minutes Im still getting a 5 TDS coming out. How the hell is that possible? Now it's reading 15-22TDS coming out!!! Going in is steady at 87.

 

[joeyhatch11]

Anyone lookin to buy a brand new RODI system LMK I got one for sale!!! 4:1 ratio is insane!!! and I can't afford to buy a 2nd membrane and pump to make it work. What a waste of $150.

 

[downbeach]

If you're going to keep a SW tank, in the long run, it's probably one of the most cost effective devices you can get.

 

[redfishbluefish]

Anyone lookin to buy a brand new RODI system LMK I got one for sale!!! 4:1 ratio is insane!!! and I can't afford to buy a 2nd membrane and pump to make it work. What a waste of $150.

Joey, let’s take a little breather here and figure out what’s going on.

What size membrane is it and what is the efficiency rating. I believe the most efficient are 75 gpd membranes at 98% ejection.

Your 22out/87in is roughly 75% ejection.

 

[jgraz]

If you're going to keep a SW tank, in the long run, it's probably one of the most cost effective devices you can get.

I can vouch for this. I was buying my water weekly at $.50 a gal. I finally broke down and got a proper system and pump and believe me when I say it the only reason I'm still in this hobby. You already have the system, just look around for a pump. You can probably find a used pump and transformer got under $100. Forget about the second membrane for now.

 

[jgraz]

Joey, let’s take a little breather here and figure out what’s going on.

What size membrane is it and what is the efficiency rating. I believe the most efficient are 75 gpd membranes at 98% ejection.

Your 22out/87in is roughly 75% ejection.

Also what is your pressure going into the system. If the pressure is low then the rejection rate is even greater and the membrane cannot properly do its job.

 

[kschweer]

Well even with the membrane hooked up and having this system running for 45 minutes Im still getting a 5 TDS coming out. How the hell is that possible? Now it's reading 15-22TDS coming out!!! Going in is steady at 87.

Your high TDS reading is most likely because it's a new system. It is recommended to run a new membrane for about an hour before it is put online.

 

[joeyhatch11]

Im not sure what the presure is going into the system, this 75GPS BRS unit didn't come with one. The book that came with the unit says it's a 4:1 ratio of waste to good water. So it would make sense seeing that the black line is a nice constant flow and the blue line is on/off, not steady at all. I let the system run for just over an hour last night before I shut it down. I had it hooked up to the kitchen sink and also had it on full blast. Anything less than that it would make the out put TDS go up. I had 0 TDS for a few minutes, at which time I saw that I lost all out put from the blue line.

What I dont get, is even with the membrane off line, once the water passed through the DI section I was still getting 35 TDS coming out. At least at that point it should have been 0. I just would have been going through the Di alot faster.