Some questions for the RO/DI experts....

[JayM]

Let me preface by saying I did not do as much due diligence as I should have when I first purchase my RO/DI system, nor did I with some of the mods I subsequently made, thus the questions I have now.

Here's what I purchased:
Water Max 6 Stage RO/DI

I should have just left well enough alone as incoming TDS runs in the high 170's to the mid 180's and coming out at zero, but it seemed to take forever so I purchased this:
Aquatec 8800 Booster Pump

TDS still zero, water is made faster, but seems like more waste, so I bought this:
200GPD Water Saver

Everything seems great. TDS still zero, but now I notice DI resin depleting faster than it had been, and final product TDS has crept up to 2ppm. Not the end of the world, but I'm a total noob and have no idea if it's normal after only about 200 gallons of water run through it. So now I'm going to do a reset, and hopefully get everything right with what I have, knowing that some of what I'm doing now likely isn't ideal.

1) Booster pump gives me 85-90 psi @ the RO membrane inlet. Is that pressure ok, or should I reduce it? It's about 55-60psi without the pump running.

2) "Water Saver" is plumbed in series, which apparently isn't ideal. Ditch it, keep it as-is, or plumb it parallel?

3) I have 2 horizontal DI housings that are about 2" diameter and about 8" long. Should I keep them mounted horizontal, or can/should they be mounted vertical? If vertical, does it matter if water is fed from the top down, or bottom up? I'm not opposed to purchasing an add-on DI kit if that would be a better idea. I'm going to spend money on new DI resin anyway.

4) I have both a 500ml and an 800ml restrictor. Are either of those ideal? Or do I need a different size? My goal is to keep concentrate to a minimum, yet not need to replace filters and/or resin more than a couple times a year.

5) Booster pump has a high pressure shut-off switch (obviously). Do I still need to use the automatic shut-off valve ?

6) Does Buckeye Hydro offer forum discounts?

Thanks in advance for taking the time.

 

[Buckeye Hydro]

We pay through the nose each month to sponsor this platform... is that what you were referring to?

 

[JayM]

We pay through the nose each month to sponsor this platform... is that what you were referring to?

Yep. Absolutely.

Seriously though, from the bit of browsing I’ve been doing today, your pricing is pretty dang competitive as it is. I just didn’t know of your existence when I purchased my stuff or I’d be good to go already.

 

[DCR]

I think your water saver is reducing your overall reject rate with a corresponding increase in TDS which is having to be removed by the DI. I assume the water saver is taking the high TDS reject from the first stage and recovering additional water from that reject. The water from the water saver is going to be higher in TDS than the water from the first stage simply due to the high TDS in the feed.

 

[Sisterlimonpot]

I agree, I think adding the 2nd membrane without properly tuning it is the main issue.

I run a very untraditional dual membrane in series and I had to get adjustable flow restrictors so that I could tune it properly. I have a thread over on humble fish detailing it.

But you'd be better off keeping with tradition.

I personally would replace the smaller DI canisters with the 10" versions. And it wouldn't hurt to get some inline TDS meters to monitor tds out of the membrane and post di.

I'm sure buckeye hydro can point you in the right direction.

I wouldn't replace what you have, I would just do those little changes.

And it wouldn't hurt to ensure you're using a quality membrane filter.

I don't know what buckeye recommends, I personally live in Phoenix and spectrapure is right up the road. I tend to buy their membranes and resin. Sorry buckeye.

Don't sweat it, this is an easy fix.

 

[JayM]

I think your water saver is reducing your overall reject rate with a corresponding increase in TDS which is having to be removed by the DI. I assume the water saver is taking the high TDS reject from the first stage and recovering additional water from that reject. The water from the water saver is going to be higher in TDS than the water from the first stage simply due to the high TDS in the feed.

Could be I suppose. TDS didn’t raise until after I had run probably 50 gallons through the water saver. My mind says it would have raised right away, but again, I’m a RO/DI noob.

I agree, I think adding the 2nd membrane without properly tuning it is the main issue.

I run a very untraditional dual membrane in series and I had to get adjustable flow restrictors so that I could tune it properly. I have a thread over on humble fish detailing it.

Same username over there?

But you'd be better off keeping with tradition.

I personally would replace the smaller DI canisters with the 10" versions. And it wouldn't hurt to get some inline TDS meters to monitor tds out of the membrane and post di.

I’m heavily leaning that direction as it seems to be the preferred method, and if nothing else, much more convenient to change resin when the time comes.

I'm sure buckeye hydro can point you in the right direction.

I was hoping so, but it seems he either doesn’t have the time or the desire at the moment.

I wouldn't replace what you have, I would just do those little changes.

DI resin canister and flow restrictors (if necessary) are the only things on the replacement list. Just trying to figure out the details with the RO membranes. Series, parallel, or just use a single unit.

And it wouldn't hurt to ensure you're using a quality membrane filter.

I don't know what buckeye recommends, I personally live in Phoenix and spectrapure is right up the road. I tend to buy their membranes and resin. Sorry buckeye.

Don't sweat it, this is an easy fix.

 

[Buckeye Hydro]

Feel free to give us a call when you are in front of the system.
Russ