Help TDS through the roof and so is my DI resin budget!

[Bradley Keck]

If your feedwater is hard enough to scale a flow restrictor, no doubt other fixtures in your house (hot water heater, dishwasher, etc) are taking a beating as well. You should consider a whole house water softener. Not difficult to install, and with our instructions, an average DIY'er can install easily.

Russ

First off, thank you for your help. I will give you a call if I cannot get this figured out. Here is what I have done. Instead of buying a TDS meter, I simply bypassed everything by disconnecting the source water line and hooked it directly into line 1 of the TDS meter that is right before the first DI resin cartridge. Then, instead of having the water go into the DI resin, I just connected an extra piece of tubing to have it empty into a 5 gallon bucket. My TDS straight from the tap read 344 consistently over 3 minute span. That would mean I am not quite getting 50% rejection rate after the membrane. Indeed we are not seeing any problems with our other appliances at this point. Sure our shower head and faucets will build up over time and I just soak them in vinegar usually and that occurs about every year or so, but nothing that should cause this RODI unit to operate like this after only 200g of use. I do plan to get a water softener though and really appreciate your willingness to help me through it. I really appreciate it and will plan to give you a call. Thank you for clarifying the concept of pressure as it relates to rejection rate too. I was hesitant to go right out and buy one anyways. My reef budget right now is planned to be put towards my first pets which will be the CUC, and any additional expenses will only set me back on getting my CUC, first corals, and first fish. I'm hoping I can resolve this without having to spend a bunch of $$$. It worked so well at first, my hope is I will get this figured out. Now that I know my TDS is 345, I think I can safely assume it is not the source water. My next step is to reinstall the membrane and I check the O-rings. I'm not confident this will do it though since it started to show high TDS before I ever touched the old membrane.

 

[Bradley Keck]

Like you I have high TDS, so because of this, I put a restrictor on my RO unit that allows more water through the restrictor than what's recommended for a 75GPD membrane to help keep it working well. This has helped lower my product water TDS as well. If your TDS meter was slowly increasing after you started your RO Unit, you may have a clog in your restrictor that you don't know about. Most people don't realize that you do need to replace that restrictor every year or two as it will get clogged or damaged over time. You may want to try replacing your restrictor and see if that helps. With that high of TDS, get one that allows slightly more water through. That's what BRS recommended for me and it helped. Good luck.

This is great info! You are correct that I had no idea that was something I needed to consider. The only thing is this unit is really brand new with only about 200g run through it. When you say you have high TDS, how high are we talking? I just measured my source water at 345. If this will fix my problem, I'm all for it though. I need to contact them again and let them know that replacing the membrane did not work and see what they suggest. I also am ready to contact Buckeye Hydro too as they have offered to help me out. I am just amazed at how many people are willing to offer a hand on R2R. I love it!

 

[Buckeye Hydro]

When you pull the membrane out, look down inside the membrane housing, and you'll see the little "cup" into which the orings seat. See if you see anything obvious like a chip/crack in the wall of that little cup.

Also, when you install the membrane, slide it in easy with two fingers. When you feel it hit the far end (the cup), put the heel of your hand on the membrane stem and push hard - you should feel the membrane go in another 1/4". It's that last 1/4" that is critical.

Russ

 

[Buckeye Hydro]

High feedwater TDS is not the focus here... but it's high TOTAL HARDNESS that will cause a membrane to scale. High TDS is not = to High Total Hardness.

 

[Bradley Keck]

High feedwater TDS is not the focus here... but it's high TOTAL HARDNESS that will cause a membrane to scale. High TDS is not = to High Total Hardness.

Thank You Russ. I'm going out there to inspect the housing and reinstall it now. Is there a way to test total hardness, or does it not really matter? I really just need to get a water softener anyways regardless. If I do that, probably will not matter what my total hardness is.

 

[Buckeye Hydro]

You absolutely will want to know your total hardness before you invest in a softener.
https://www.amazon.com/Hach-145300-Total-Hardness-Model/dp/B008FM7WLU

 

[Bradley Keck]

I know this isn't the best pic of the cup at the bottom, but it was the best I could get. I could not see any cracks or chipped pieces. the one thing I noted was the gasket near the top of the membrane housing itself is slightly crooked. I reinstalled the membrane and made sure to seat it all the way. Hooked it back up and the tds started at 240 and gradually went down to 94. It then crept back up to 127. When I started it last night it did the same thing. It stabilized at 127-128 for a few minutes then after about 30min it was up to 190.

 

[Bradley Keck]

You absolutely will want to know your total hardness before you invest in a softener.
https://www.amazon.com/Hach-145300-Total-Hardness-Model/dp/B008FM7WLU

Thank you thank you!

 

[Buckeye Hydro]

Sometimes the wall of that cup cracks, but the crack does not open up/become visible until you force the membrane into the cup.
So if/after we eliminate a few other possibilities when you call us, I'd suggest you ask your vendor for a replacement RO membrane housing.

 

[Bradley Keck]

Sometimes the wall of that cup cracks, but the crack does not open up/become visible until you force the membrane into the cup.
So if/after we eliminate a few other possibilities when you call us, I'd suggest you ask your vendor for a replacement RO membrane housing.

Thanks Russ, I'm calling now.

 

[Bradley Keck]

OK. So, after talking to Russ from Buckeye Hydro and going through all my connections on the RODI unit, we decided it was time to check my waste water to RODI ratio. After letting it run for 5 minutes, I started filling up one dixie cup of RODI and another of waste water. Well, by the time Ifilled one dixie cup of RODI, I had just covered the bottom of the waste water cup! I checked my connections on the membrane housing again and made sure I had the lines to cup right on each, twice. No doubt about it, my waste to RODI ratio is like 1/6. Think this might be my problem. To be sure, I opened the flush valve for the membrane and the pressure dropped from 52 to 31 and water starting pouring out of the waste water line. Going to call BRS and see if they know what might be wrong to cause this. No wonder my TDS are so high at line 1!

 

[Buckeye Hydro]

My bet is that your flow restrictor is bad.

Email us some pics if you'd like so we can visually check the plumbing.

Russ

 

[Bradley Keck]

Sent two pics. Thanks Russ!

 

[Buckeye Hydro]

Plumbing looks ok.

 

[Bradley Keck]

Plumbing looks ok.

Thanks Russ!

 

[Bradley Keck]

Contacting BRS next.

 

[pwilliaml]

This is great info! You are correct that I had no idea that was something I needed to consider. The only thing is this unit is really brand new with only about 200g run through it. When you say you have high TDS, how high are we talking? I just measured my source water at 345. If this will fix my problem, I'm all for it though. I need to contact them again and let them know that replacing the membrane did not work and see what they suggest. I also am ready to contact Buckeye Hydro too as they have offered to help me out. I am just amazed at how many people are willing to offer a hand on R2R. I love it!

Hey Bradley, sorry it took so long to reply. Glad you found out your waste water to product water ratio was too low. It really does sound like you have a restrictor issue or a clog in the waste water line somewhere. Restrictors are cheap and easy to replace. Of note, I know you said you hadn't made much water with your unit, but you said you had it off line for a while. If you have hard water and the waste water line sat for a while and dried up, hard scale may have formed in the line and clogged the restrictor or waste water line. For what it costs and what you probably already have, it's pretty cheap to change out all the RO lines on the waste water side, or even all of them. For what it's worth, my TDS is nearly 600 and my hardness I had tested at 25 which is crazy hard water, but not surprising as I live in Florida where our source water comes from limestone caverns in the groundwater. You can get a free water sample done by picking up a kit at Home Depot and sending it in. Just be prepared for the company that processes them to try and sell you a water softener. Good luck. As a temporary fix if you need water now, crack open your flush valve a little until you get a better waste to product ratio. With my hard water and TDS of 600 ppm, I'm lucky if I get 12 ppm on the outlet which is still 98% rejection, but the initial high TDS water kills me.

 

[Bradley Keck]

Hey Bradley, sorry it took so long to reply. Glad you found out your waste water to product water ratio was too low. It really does sound like you have a restrictor issue or a clog in the waste water line somewhere. Restrictors are cheap and easy to replace. Of note, I know you said you hadn't made much water with your unit, but you said you had it off line for a while. If you have hard water and the waste water line sat for a while and dried up, hard scale may have formed in the line and clogged the restrictor or waste water line. For what it costs and what you probably already have, it's pretty cheap to change out all the RO lines on the waste water side, or even all of them. For what it's worth, my TDS is nearly 600 and my hardness I had tested at 25 which is crazy hard water, but not surprising as I live in Florida where our source water comes from limestone caverns in the groundwater. You can get a free water sample done by picking up a kit at Home Depot and sending it in. Just be prepared for the company that processes them to try and sell you a water softener. Good luck. As a temporary fix if you need water now, crack open your flush valve a little until you get a better waste to product ratio. With my hard water and TDS of 600 ppm, I'm lucky if I get 12 ppm on the outlet which is still 98% rejection, but the initial high TDS water kills me.

I had not considered having a clog in the waste water line! BRS has shipped a new housing and flow restrictor to try and see if that fixes it. I am going to get my water tested for hardness, and you know what, I probably should get a water softener anyways. Thank You for your help. I'll post an update once I replace the housing and flow restrictor.

 

[Bradley Keck]

Well, here is the latest. I received the replacement housing and flow restrictor in two days, (thanks BRS!) and got them installed. Before I replaced them, I checked the flow out of my waste water line and the TDS at line 1. The waste water was barely a drip. I opened the flush valve and water started gushing out. This told me I had no clogs in the waste water, but that when the flush valve was closed hardly anything was coming out. The TDS at line 1 read 188. I installed the new valve and housing and turned the system on. Immediately I could see a constant stream of waste water with the valve closed. This was a good sign! Next I checked my TDS. They started in the 190 rage, after about 2 minutes they were down to 88, and then I hoped for it to continue to decrease. Well, it didn't. They gradually crept up to 122. Sigh.. Overall, my wastewater to RODI ratio is better for sure and my TDS are down by about 60 TDS. But, I am still seeing way too high TDS at line 1 compared to the 12-20 TDS I was getting for the first 180 gallons or so. Kind of at a loss now. For good measure I again checked my TDs from the tap and it read 338. Not sure what to do now, but I cannot continue to replace DI resin cartridges every 20gallons that's for sure.

 

[pwilliaml]

Bradley, when you changed out your housing and flow restrictor did you change your membrane too? If you made a fair amount of water with bad product to waste water ratio you may have mucked up your membrane to the point where you won't get great product TDS. I hate to say it, but it might be worth replacing it as well. The 75 GPD ones from BRS are awesome. I have 600 TDS and before replacing my membrane I was getting 18 on the outlet, now I get 4 on a brand new membrane. Either way, I would continue to monitor your waste water line when your flushing valve isn't open to make sure you don't get another clog somewhere or fouled restrictor.