DI Filter (RODI) aging prematurely?

[jmatt]

My BRS RODI system has generated less than 60 gallons of water since I got it. But the DI canister is one-third "brown" at this point. My understanding is that once the entire unit is brown, it's time for a new filter.

Is that incorrect? Shouldn't this filter be good for more than, say, at least 200 gallons?

Is it typical for it to remain half-filled with water afterwards, or am I supposed to purge it or something?

 

[Woodyman]

My BRS RODI system has generated less than 60 gallons of water since I got it. But the DI canister is one-third "brown" at this point. My understanding is that once the entire unit is brown, it's time for a new filter.

Is that incorrect? Shouldn't this filter be good for more than, say, at least 200 gallons?

Is it typical for it to remain half-filled with water afterwards, or am I supposed to purge it or something?

Being half full is normal.

As far as capacity it will vary based on your source water and how much gets through to your DI from RO membrane(s).

CO2 can also dramatically alter DI performance.

 

[Woodyman]

Here's a handy guide for you.

Lower nitrates by raising phosphate??

I have had an issue getting my nitrates to drop below 10ppm. Let me start with my tank information and parameters. I have a e170 that i have added a sump to. Run the hydra 26 hd that came with the tank on a slightly modified setting that BRS came up with to replicate the coral lab. 200-250 par...

www.reef2reef.com

 

[Sean Clark]

This rate of consumption can be totally normal depending on your setup and water composition. Not just TDS but positive vs negatively charged ions that make up that TDS and the DI resin that you choose.

 

[A_Blind_Reefer]

Agreed, the rate of depletion really depends on your source water. In your case, with only making 60 gallons, it would be worth it to upgrade to a three di canister system. That’s if you only have the single “mixed” di canister. With three, you would have a cation, an anion, and then a mixed di canister. In my scenario, I blow through anion resin about three to one compared to the cation and mixed. However, it lasts much longer than a mixed resin. With a mixed resin, the cation and anion resins are mixed 50/50. Typically you’ll burn through one much faster than the other. So, your basically throwing away half of your resin when it’s still good. Also, pressure going through the membrane and flushing have a part to play. You want 60-75psi going through the membrane for better efficiency. An auto flush system helps keep everything in good shape.

edit.. also as far as being half full, it’s kinda normal. You can just slightly loosen the canister housing as it fills to let the air escape if you’re adhd like me but it’s not necessary

 

[Spare time]

It's a good idea to bypass the di resin when flushing the unit everytime you turn it on (for about a minute until the incoming tds to the resin drops down to normal levels).

 

[HuduVudu]

Chloromines can cause problems with DI resins.

 

[Jeffcb]

My BRS RODI system has generated less than 60 gallons of water since I got it. But the DI canister is one-third "brown" at this point. My understanding is that once the entire unit is brown, it's time for a new filter.

Is that incorrect? Shouldn't this filter be good for more than, say, at least 200 gallons?

Is it typical for it to remain half-filled with water afterwards, or am I supposed to purge it or something?

What's the TDS ?

 

[A_Blind_Reefer]

Chloromines can cause problems with DI resins.

This is true. Two carbon block filters could help with that if it’s a problem

 

[jmatt]

What's the TDS ?

In is like 6 or 8, out is zero. The source is well water that goes through a softener first.

 

[jmatt]

It's a good idea to bypass the di resin when flushing the unit everytime you turn it on (for about a minute until the incoming tds to the resin drops down to normal levels).

It's only been used three times and I have not done a backwash yet. How often should the backwash be done?

 

[jmatt]

With three, you would have a cation, an anion, and then a mixed di canister. In my scenario, I blow through anion resin about three to one compared to the cation and mixed. However, it lasts much longer than a mixed resin. With a mixed resin, the cation and anion resins are mixed 50/50. Typically you’ll burn through one much faster than the other.

Thanks, I may have to look into that.

 

[Spare time]

It's only been used three times and I have not done a backwash yet. How often should the backwash be done?

I flush it everytime I turn it on. However, there will always bee a huge tds spike when the unit turns on. If you get an inline tds meter, you will see the tds of the water leaving the ro membrane skyrocket and then slowly jump down after a minute or so. I found that this rapidly depletes the di resin, so I made a bypass (a Y splitting into two valves that allow the flow either to the drain or to resin).

 

[A_Blind_Reefer]

It's only been used three times and I have not done a backwash yet. How often should the backwash be done?

Pretty much every time. An auto flush is pretty slick, especially if you’ve ever manually flushed and taken the boat out for a long weekend, forgetting to close the valve.

 

[Sean Clark]

Not the most ideal pic but sediment 1, solenoid, sediment 2, carbon 1, carbon 2, ro 1, ro 2, cation 1, cation 2, anion 1, anion 2, mixed bed 1, mixed bed 2

 

[Woodyman]

In is like 6 or 8, out is zero. The source is well water that goes through a softener first.

Well water....

More than likely this is the biggest contributor to your wuicl exhaustion of DI.

You more than likely have excess CO2, especially as you soften the well water as well.

Now flushing the membrane, and purging the RO at startup prior to DI is explained and recommended in the link I gave you above. There are some schematics in that post as well.