Question about my RO unit

[aerius007]

I have a coralife 4-stage RO unit and added a dual tds meter, no pump.

http://www.drsfostersmith.com/produ...93&pcatid=12093

I only have it running once or twice a week. I have a couple of questions.

1) I have well water going through a high-quality water softener before the RO, pressure is anywhere from 40-45psi. Is that enough? Reason I ask it that I'm getting about half the rated amount of water per day. It has been like that since the first day I got it. The good to waste ratio is right, about 1:3-1:4

2) If I dont run it for a couple of days the reading on the tds meter is pretty high out of the RO, close to 100 but within a minute or two drops to 8. Why would I be getting the initial high reading?

3) I think it is time to change the DI resin, I was initially getting a 0-1 reading but it has now crept up to 5. I was going to buy a few pounds of resin but when I looked at the cartridge it doesnt look like I can replace just the resin. There is the outer canister that unscrews (same as the other two stages), and inside that there is a thinner canister that contains the resin. That inner canister doesnt seem to be threaded anywhere and looks as if when its exhausted it needs to be replaced.

4) The outer canister of the DI stage never completely fills with water. At the most it gets half way up the resin. Is this normal, or is it a problem that has to do with low pressure or air being trapped?

I dont have a storage tank, ATO or anything like that. Just the four stages that fill my 5 gallon jugs.

 

[MeVsTheWorld]

1) I think it should be around 65 psi for maximum operation.
2) Mine says if it's not run for around 3 days, you should let it run for 5-10 minutes and discard, then use the new water.
3) ? anything over 0, I would change.
4) mine does the same, instructions say that is how it operates.

 

[MMOORE0324]

Plus remember that in the winter with cold source water... Production will slow. Mine says 65-75 psi is normal operating pressure. Its fine that your DI canister doesn't fill up. Mine doesn't either. I would for sure change your cartridges.

 

[itZme]

I took a sharp knife and cut around the top seam of the DI cartridge on my Kent RO/DI unit. Then I could dump out the resin and refill with new mixed-bed resin.

The problem with your TDS creeping up on you when not being used is called "TDS creep".
It is because the particles that are on the rejection side creep across the membrane while it is submerged in the water and not running. That's why they recommend running it for longer periods of time like filling a container instead of just topping off a few ounces at a time right from the RO system.

Mine never fills more than 1/2 to 2/3 with water either.

 

[aerius007]

Thanks for the answers!!! I ordered a refillable DI cartridge filled with resin for just under $20, I will buy some more in bulk ASAP to have on hand. I wish I had more pressure to fill quicker but its not worth the extra money to get a pump right now.