Want back in hobby issue w/ RO/DI

[Vin7250]

I want back in the hobby. I have a 90 gallon in-wall tank w/ 150lbs of live rock and its half full. No livestock. My issue is this - at the house i'm living in the well water is VERY high on iron. I have access to a whole house filter and it does a good job (good enough for us humans) but it still destroys DI resin in a matter of a week and the waste water to clean ratio is absurdly high so i'm dumping WAYYYY too much water. I'd like to figure out a way to get back in the hobby with this tank but either:
1. not rely on ro/di
2. figure out a way to completely minimize the di consumption and continue to make water in small quantities

I'm not sure buying water is even a thing anymore... I used to by this RO water from walmart and now they never have it. I'm curious if anyone else has overcome the well water issue without breaking the bank and was able to support a reef? Any help would be appreciated as the wife is starting to get annoyed w/ the half full and not running in-wall tank

-Vin

 

[kfisc]

Welcome back to the hobby! This is a bit of a complicated issue. A thread here addressed it awhile back:

Iron in tap water- getting through RODI

 

[kharmaguru]

I want back in the hobby. I have a 90 gallon in-wall tank w/ 150lbs of live rock and its half full. No livestock. My issue is this - at the house i'm living in the well water is VERY high on iron. I have access to a whole house filter and it does a good job (good enough for us humans) but it still destroys DI resin in a matter of a week and the waste water to clean ratio is absurdly high so i'm dumping WAYYYY too much water. I'd like to figure out a way to get back in the hobby with this tank but either:
1. not rely on ro/di
2. figure out a way to completely minimize the di consumption and continue to make water in small quantities

I'm not sure buying water is even a thing anymore... I used to by this RO water from walmart and now they never have it. I'm curious if anyone else has overcome the well water issue without breaking the bank and was able to support a reef? Any help would be appreciated as the wife is starting to get annoyed w/ the half full and not running in-wall tank

-Vin

If you have a water softener that will remove alot of the iron. Also, iron rejection should be over 90% at the RO stage so I doubt that's killing your DI. It's more likely carbon dioxide in the well water which there's not much you can do anything (affordable) for. Do you have a booster pump for the RO system? Low water pressure (30-50psi) from a well system will cause excess waste production and generally poor performance.

I'm on a well for 20yrs now, softened water, RODI system with booster pump and I keep a reef. I find the DI usage varies throughout the year so I assume that is also the CO2 variable. Right now I've been on the same DI for months but sometime it can be like you and used up in weeks.

 

[Vin7250]

I see... I was thinking iron because the DI cartridge looks almost stained but maybe that's just the color of depleted cartridge due to the co2. But it sounds like you are saying the high rejection rate is most likely a different issue that may be solved with a booster pump for the ro/di? I could live with making the water if the DIs would last a couple of months but sometimes I get one use out of them

Thanks for the link kfisc! I will check it out!

 

[Reefing102]

I’m not to skilled with RO stuff. I run an RO but it’s a basic 4 stage. But Buying water is still definitely a thing. Almost all of my local LFS’s sell RO. If you’re close to the coast, you may be able to import natural sea water for water changes. Just some thoughts

 

[kharmaguru]

But it sounds like you are saying the high rejection rate is most likely a different issue that may be solved with a booster pump for the ro/di?

Yes, low pressure will cause more water to go to the waste line. Is the flow restrictor matched to the membrane?

How many gallons of water are produced before the DI is dead and how are you determining that it's dead - TDS meter or colour change?

 

[Vin7250]

@kharmaguru I'm going to start a revival thread since I believe this tank is worthy But yes the flow restrictor is matched to the membrane and I'm not exactly sure but it's something like < 50. And generally I would look at the color and start testing and once I get to about 5tds (which I think is already too high) I consider the DI exhausted. But I just hooked up a booster pump that I had in the garage and it's working a heck of a lot better. I'm going to replace all the filters and the RO membrane today and start to do some testing while I make some water for the tank to refill.

I'll post plenty of content on the rebuild post.

 

[Vin7250]

I’m not to skilled with RO stuff. I run an RO but it’s a basic 4 stage. But Buying water is still definitely a thing. Almost all of my local LFS’s sell RO. If you’re close to the coast, you may be able to import natural sea water for water changes. Just some thoughts

I'd love to but nothing in my area as far as I can tell, except that $15 Petco premixed saltwater which isn't really going to cut it. Trying to keep costs down where I can. The only LFS I remember in my area that would sell me water is, sadly, long gone.

 

[kharmaguru]

@kharmaguru I'm going to start a revival thread since I believe this tank is worthy But yes the flow restrictor is matched to the membrane and I'm not exactly sure but it's something like < 50. But I just hooked up a booster pump that I had in the garage and it's working a heck of a lot better. I'm going to replace all the filters and the RO membrane today and start to do some testing while I make some water for the tank to refill.

I'll post plenty of content on the rebuild post.

Glad to hear it!

something like < 50

Less than 50 gallons to dead DI or is this meaning something else?

 

[Vin7250]

Yea should have been more clear, I'm typing too fast Less than 50 gallons of clean RO/DI and the color has changed. Then I start testing. Check my earlier reply to you - I just updated it to be more clear. We will see by later today if the TDS stays low for longer and the color doesn't change after about 50 gallons but for sure it's already creating clean water MUCH faster than before the booster pump which would indicate to me less water is being wasted. Before it could take 5+ hours to fill a five gallon bucket - now I got one filled in less than 2 hours (about an hour and a half). I think that's pretty good!

 

[kharmaguru]

Yea should have been more clear, I'm typing too fast Less than 50 gallons of clean RO/DI and the color has changed. Then I start testing. Check my earlier reply to you - I just updated it to be more clear. We will see by later today if the TDS stays low for longer and the color doesn't change after about 50 gallons but for sure it's already creating clean water MUCH faster than before the booster pump which would indicate to me less water is being wasted. Before it could take 5+ hours to fill a five gallon bucket - now I got one filled in less than 2 hours (about an hour and a half). I think that's pretty good!

I thought I should mention this in case you are unaware. The initial water from the membrane will have very high TDS ( from what is called TDS creep). Generally the best method is to run the RO to waste ( or drinking water or for plants if you don't want to waste it) for 10 minutes before letting it enter the DI stage. This can be done with a Y connector and a couple valves between the RO and DI stage. Water exiting the DI should always be zero TDS.

 

[Vin7250]

You are referring to when I change the cartridges to the new ones and replace the ro membrane? I didn't know that so basically can i unhook from the di and just run the ro membrane down the drain for ten minutes or so? I was always under the impression to run the entire unit DI and all for ten mins before keeping the water. Curious if just unhooking the di for a bit would do the trick. Thanks for all your help sir!!!!

 

[kharmaguru]

You are referring to when I change the cartridges to the new ones and replace the ro membrane? I didn't know that so basically can i unhook from the di and just run the ro membrane down the drain for ten minutes or so? I was always under the impression to run the entire unit DI and all for ten mins before keeping the water. Curious if just unhooking the di for a bit would do the trick. Thanks for all your help sir!!!!

I mean every time you make water. For instance my RO will start over 100 TDS and then fall to 3 or less after a few minutes. I usually let it run for 10 before I switch it into the DI stage. Yes, you can disconnect the DI stage as you suggested while it flushes. Something to invest in would be a dual TDS meter like this one. Measure after the membrane and again after the DI then you'll always know what's going on.

What is the TDS of your well water?

 

[griss]

I thought I should mention this in case you are unaware. The initial water from the membrane will have very high TDS ( from what is called TDS creep). Generally the best method is to run the RO to waste ( or drinking water or for plants if you don't want to waste it) for 10 minutes before letting it enter the DI stage. This can be done with a Y connector and a couple valves between the RO and DI stage. Water exiting the DI should always be zero TDS.

This exactly. I have a T fitting between my RO membrane output and my DI cartridges.

The first site of the T fitting is coming from the RO. The next side goes to my plant water bucket with a shut off valve after the T fitting. The third side goes to my DI with a shut off valve before the DI.

When I am NOT making water, both shut off valves are closed. When I need to make new water, I first flush the TDS creep water from the membrane by opening the valve to the plant water bucket. As @kharmaguru mentions, the TDS coming from the membrane is usually quite high. I wait for it to drop down in the single digits, close the shut off valve to the plant water and open the shut off valve going to the DI. Since discovering this trick, I have reduced the system's consumption of DI resin in a huge way.

If you're not into doing a DIY TDS creep bypass like I did, apparently Buckeye Hydro sells something you could use.

 

[griss]

Here's a post I made about it a couple years back.

I was having the same issue with my DI resin. It was depleting really fast. New filters and membrane did not remedy the issue and my pressure through the unit was as recommended by BRS.

What you may be experiencing is what's called, "TDS creep." Essentially, when the RO/DI system sits idle, TDS creeps back out of the membrane. When the system starts up again, this high TDS water in the membrane housing is pushed into the DI cartridges, depleting them rapidly.

My system was set up with a float valve in the sump connected directly to the RO/DI system. So, when the water level in the sump dropped, the RO/DI started up. Basically, throughout the day, my system was sending high TDS water into my DI carts. I now use a container to hold newly made RO/DI that is connected to the float valve in the sump.

I, then, put a valve between the membrane housing and DI carts. Whenever I go to make water, I open this valve first and let it run into the drain. I monitor the TDS coming out of the membrane until it drops, then close the valve and let the filtered water go through the DI resin to my topoff tank.

Since doing this, my DI is lasting MUCH, MUCH longer.

 

[griss]

I mean every time you make water. For instance my RO will start over 100 TDS and then fall to 3 or less after a few minutes. I usually let it run for 10 before I switch it into the DI stage. Yes, you can disconnect the DI stage as you suggested while it flushes. Something to invest in would be a dual TDS meter like this one. Measure after the membrane and again after the DI then you'll always know what's going on.

View attachment 32377132

What is the TDS of your well water?

Yep, IMO everyone should have one of those AND keep in calibrated.

 

[Vin7250]

Makes sense and I will definitely invest in one. I currently have the tank filled (took all day) and am just adjusting salinity a slight bit with some top off water. It's cleaned finally after all this time and the XF-6 is up and running again. Thanks for all the advice all!!! I hope you guys follow my 90 revival thread... will be doing some updates to it later tonight w/ photos of today's work

 

[griss]

I hope you guys follow my 90 revival thread... will be doing some updates to it later tonight w/ photos of today's work

Already following it