350 PPM TDS before RO, 10 PPM after RO, 0 PPM after DI - chewing through resin

TinyChocobo · Feb 16, 2018

Hey guys.

My tap water has 350 PPM TDS which seems pretty terrible.

I have a Bulk Reef Supply 150 GPD 6 Stage RO/DI and am seeing 10 PPM after the RO and 0 ppm after DI but it’s absolutely chewing through DI resin.

I have the auto flush which is a 500 ml/min restrictor which is what BRS recommended for this unit. I’m wondering if I should be using a higher flow restrictor like 700-800 ml/min due to how high the TDS is in the source water?

Monterey Bay Coral · Feb 16, 2018

Do you use well water? Could be due to high co2 in the water.

saltyhog · Feb 16, 2018

Wow, I feel lucky. TDS of my tap water is 37, after RO it's 0-1. My resin lasts a loooong time.

JMetaxas · Feb 16, 2018

What does “chew through resin” mean? How many gallons of 0 TDS do you get?

TinyChocobo · Feb 16, 2018

Monterey Bay Coral said:
Do you use well water? Could be due to high co2 in the water.

It is city water.

saltyhog said:
Wow, I feel lucky. TDS of my tap water is 37, after RO it's 0-1. My resin lasts a loooong time.

I wish!

JMetaxas said:
What does “chew through resin” mean? How many gallons of 0 TDS do you get?

I’ve made ~35 gallons and I’ve used about 1/8th of the first resin stage.

JMetaxas · Feb 16, 2018

So you expect to basically get ~300 gallons per DI cartridge?

TinyChocobo · Feb 16, 2018

JMetaxas said:
So you expect to basically get ~300 gallons per DI cartridge?

To be honest I’m not sure what is “normal” I just know this is using resin a LOT faster than the last RO/DI I set up at my house. This one is at my work.

GSPClown94 · Feb 16, 2018

What is the water pressure going into the RODI unit?

TinyChocobo · Feb 16, 2018

Andrew Florjancic said:
What is the water pressure going into the RODI unit?

85 PSI.

Mr.Fishtank · Feb 16, 2018

85 seems high to me. My pressure is at 55psi. Are you using a booster pump?

TinyChocobo · Feb 16, 2018

Mr.Fishtank said:
85 seems high to me. My pressure is at 55psi. Are you using a booster pump?

Yes. It’s 60 before booster. The water is very cold. BRS says not to exceed 100psi. It was 90 I turned it down to 85 for some safe headroom.

Crabs McJones · Feb 16, 2018

When you say 150gpd unit. Is this the 75 gallon per day with the 150 gallon per day upgrade to it? As in the ro units are hooked in series?

TinyChocobo · Feb 16, 2018

crabs_mcjones said:
When you say 150gpd unit. Is this the 75 gallon per day with the 150 gallon per day upgrade to it? As in the ro units are hooked in series?

It’s this one:
https://www.bulkreefsupply.com/6-stage-150gpd-plus-water-saver-ro-di-system-bulk-reef-supply.html

So I believe it is the 75 GPD with the upgrade.

GSPClown94 · Feb 16, 2018

Add a third RO membrane lol

Crabs McJones · Feb 16, 2018

TinyChocobo said:
It’s this one:
https://www.bulkreefsupply.com/6-stage-150gpd-plus-water-saver-ro-di-system-bulk-reef-supply.html

So I believe it is the 75 GPD with the upgrade.

Unfortunately i think one of the side effects to that unit is increased di consumption. I noticed after I did my 150gpd upgrade I'm burning through di as well. Becaise the waste water from one membrane is fed directly into the other so it's a bigger concentration of tds going into the second unit, therefore your production waters going to have higher tds of say 10-15 where with a standard 75gpd it may only be 1-5 tds

TinyChocobo · Feb 16, 2018

crabs_mcjones said:
Unfortunately i think one of the side effects to that unit is increased di consumption. I noticed after I did my 150gpd upgrade I'm burning through di as well. Becaise the waste water from one membrane is fed directly into the other so it's a bigger concentration of tds going into the second unit, therefore your production waters going to have higher tds of say 10-15 where with a standard 75gpd it may only be 1-5 tds

So I could test disconnecting one of the membranes and run 75 GPD and see how much resin I use?

I was thinking running a larger restrictor (more waste water down the drain) would help offset the higher TDS?

Any reason I can’t go parallel instead of sequential for the membranes? A couple Y fittings and a couple check valves.

KJAG · Feb 16, 2018

Just going off what I’ve learned over the years with my unit and countless hours of troubleshooting with Spectrapure customer service( another almost impossible feat getting them on the phone) but..
Is your unit hooked up to an ATO? If so, Stop.
Find out what your injection rate is( should be about 4:1)
Use quality cartridges. (Spectrapure/ Buckeye) I’ve tried to save money on cheaper replacement resin/ cartridges and it just ended up costing me more money in the long run.
Add a water softener before the RODI unit. This has helped prolong the life of my membranes and cartridges. I bought an “On the Go” RV portable softener off Amazon( not exactly cheap.) Also comes in handy for washing cars: as another aside I fill up a 20 g trash can of DI and rinse my truck after with a sump pump/ hose, and I barely have to dry mine or my wife’s car when washing. It’s Gold.) But I digress..
My tap here in Oxnard California is 480 out of the tap, which is worse than yours, and my resin and membranes last drastically longer than they used to after making these changes. I was at witt’s end before these adjustments.

Crabs McJones · Feb 16, 2018

TinyChocobo said:
So I could test disconnecting one of the membranes and run 75 GPD and see how much resin I use?

I was thinking running a larger restrictor (more waste water down the drain) would help offset the higher TDS?

Any reason I can’t go parallel instead of sequential for the membranes? A couple Y fittings and a couple check valves.

Correct, the first membrane may only putting out product water if 2 to 4 red, but the second unit may be putting out 4 to 8 tds, and when the two come together you get your increased tds going into your di resin. In theory if you disconnect the second ro membrane your tds consumption will go down, however you'll produce more waste water and it'll take longer to produce ample amounts of product water.

TinyChocobo · Feb 16, 2018

Shores805 said:
Is your unit hooked up to an ATO? If so, Stop.

No - it’s hooked up to a 20 gallon pressurized R/O storage tank (about 14 gallons stored).

Shores805 said:
Find out what your injection rate is( should be about 4:1)

How would I do that? Have clean go to one container and waste to another and measure amounts?

Shores805 said:
Use quality cartridges. I’ve tried to save money on cheaper replacement resin/ cartridges and it just ended up costing me more money in the long run.

I’m using the resin that came with the unit from BRS.

Shores805 said:
Add a water softener before the RODI unit. This has helped prolong the life of my membranes and cartridges. I bought an “On the Go” RV portable softener off Amazon( not exactly cheap.) Also comes in handy for washing cars: as another aside I fill up a trash can of DI and rinse my truck after and I barely have to dry mine or my wife’s car when washing. It’s Gold.) But I digress..

I’ll have to look into that. I lease the office space so I doubt the land lord will put in a softener.

TinyChocobo · Feb 16, 2018

crabs_mcjones said:
Correct, the first membrane may only putting out product water if 2 to 4 red, but the second unit may be putting out 4 to 8 tds, and when the two come together you get your increased tds going into your di resin. In theory if you disconnect the second ro membrane your tds consumption will go down, however you'll produce more waste water and it'll take longer to produce ample amounts of product water.

Can I run the membranes in parallel instead of in sequence?

Basically Sediment -> Carbon 1 -> Carbon 2 -> Y Fitting -> Check Valve on each -> Membrane on each -> Y Fitting -> DI

I think I would also need a Y to join the waste water outputs too for the restrictor.