New to RODI

[gregzz4]

After a bit of lookin', I probably should mod the original post, but I'll leave it for the membrane question.
It's a Vertex unit. With the waste water valve turned off, I'm still getting waste water. And I wouldn't be surprised if it's close to your 80/20
The storage is a cleaned out food industry 45g drum
I've heard of some people keeping powerheads in their storage tanks. Maybe that's for stagnant issues?
I did a taste test. Even removing 8ppm and the Chlorine, wow, what a difference in both taste and smell
The fishies are going to love this, as is my bottled-water buyin' wife

[Myka]

Originally Posted by gregzz4

The fishies are going to love this, as is my bottled-water buyin' wife

Lots of people suggest collecting water for drinking after the RO, but before the DI. The reef + drinking water systems on the market use a valve to bypass the DI resin for drinking water. I'm not totally sure why. I believe it is more taste than anything (I know I find DI water tastes funny), although I have heard things like DI water is ionicly aggressive and some impurities from the DI resin makes it into the water so is not healthy to drink, but I am not sure of the validity of those claims.

Btw, when it comes time to replace the RO membrane (years from now) replace it with a 75 gpd or 150 gpd RO membrane which is more efficient. Since you have REALLY low tds to begin with it really doesn't matter though. If you do change the membrane select a flow restrictor of the same rating.

As far as 1:1 output, I think you're quite alright with that considering you're only putting 8 ppm into the system to begin with. I have been using 1.5:1 for about 2000 gallons nows starting with 160-180 ppm and I'm not having any issues with the membrane clogging so far.

[gregzz4]

Thanks Myka and I read up on drinking DI water. I see enough info to stay away from it.
For the membrane, I'll definately go with either a 75 or 150 with the next purchase, and I know what you mean about the restrictor. Too bad for me I didn't want to bother anyone before I bought the 100gpd unit I have now. It'll definately do the trick.
I could have bought the fancy shmancy Vertex automatic unit for what I've spent on what I have, but I have 2 gauges, 3 TDS meters and the ability to by-pass the DI.
5 of one and 6 and a half, or is that 7, of the other, oh, no wonder my budget is off

[gregzz4]

So I got sidetracked with the repairs ...
A couple of my questions are, do I need to stir my storage tank ? Aerate it or heat it ? I'll gather heating it is a waste as it's in a warm room.

[Myka]

The RO/DI doesn't need to be stirred, aerated, or heated. Whatever you end up doing with the water will make it a moot point. You will either put it into a salt mixing barrel where you will heat and mix (aerate) it, or you will put it in a tub for top off where it will just sit and get cold anyway.

Honestly, I would be ticked right off if I had 8 ppm going into the RO and having anything other than 1:1 water ratio. Most membranes suggest 4:1 which is for flushing the membrane as it runs to keep it from scaling, but with only 8 ppm going in, imo you don't have much to worry about. That RO membrane will last you probably 5+ years with that little load you're putting on it.

With 160-180 ppm my RO membranes last 2-3 years. I would rather replace my RO membrane once a year than waste that much water. So far, I haven't had an issue though...my membrane is lasting just fine at 1.5:1.

[gregzz4]

Thanks Myka. And I'm not so concerned about the ratio as I was about harming the membrane with too much back pressure if I was to shut off the waste valve. Turns out I have no control over it anyway. Unfortunately, unless I change something, the valving on my system allows this much to bypass. So far though, looks like I'll get about 75gpd. I can live with that