RO/DI filter

[Philliesphan]

Hello all! I am sure this topic has been discussed here. I'd just like some input here. I have an RO/DI filtration system under my sink. Normal sink faucet tap water is reading 219-223. After my sediment, GAC, CTO, membrane, inline carbon, and DI filter, I get a 0TDS reading for about a month. Then it hops up to 2-3. If I bypass the DI filter, I get a 11-13TDS reading. I'm on well water and it seems I'm burning through DI filters rather quickly. I have a water softer with UV light in basement. Should I add another DI filter? I'm frustrated and love an answer to help me fix this! Please and thank you all for your time!

 

[KStatefan]

I would start with looking at the membrane. You should be able to get better rejection then 94.5%. What is your pressure at the membrane?

 

[Glenner’sreef]

Hello all! I am sure this topic has been discussed here. I'd just like some input here. I have an RO/DI filtration system under my sink. Normal sink faucet tap water is reading 219-223. After my sediment, GAC, CTO, membrane, inline carbon, and DI filter, I get a 0TDS reading for about a month. Then it hops up to 2-3. If I bypass the DI filter, I get a 11-13TDS reading. I'm on well water and it seems I'm burning through DI filters rather quickly. I have a water softer with UV light in basement. Should I add another DI filter? I'm frustrated and love an answer to help me fix this! Please and thank you all for your time!

And are you able to backflush your membrane each time? Or occasionally?

 

[Glenner’sreef]

And are you able to backflush your membrane each time? Or occasionally?

Its called a membrane flush valve. Install inline and cheap. Will extend the life of your membrane.

 

[Philliesphan]

I would start with looking at the membrane. You should be able to get better rejection then 94.5%. What is your pressure at the membrane?

How do I find out the pressure?

 

[Philliesphan]

Its called a membrane flush valve. Install inline and cheap. Will extend the life of your membrane.i

And are you able to backflush your membrane each time? Or occasionally?

I attached a pic here. Do I have one installed?

 

[KStatefan]

How do I find out the pressure?

With a pressure gauge

 

[Glenner’sreef]

I attached a pic here. Do I have one installed?

Doesn’t look like it. Google this.

 

[Philliesphan]

Doesn’t look like it. Google this.

Okay I will do that. And what does the flush valve do?

 

[Glenner’sreef]

Okay I will do that. And what does the flush valve do?

It creates a fast flow of water across the surface of the membrane removing deposits which get stuck to the surfaces. It also reduces the concentration of salts in the housing. That can occur when the system is not in use.

 

[redfishbluefish]

I'd like to take a step back and understand what you have.....Does the RO system you have under your sink have a 3-5 gallon tank attached? And a faucet on the sink to dispense that water? If so, you don't want to us that water to run through your DI....it has a good amount of TDS....so that it tastes OK to drink. These tanks constantly fill on demand. That is, when you use the faucet to draw a glass of water, the unit "turns on" to refill the tank. Every time it turns on, you get break-through TDS that ends up in the tank.

To fix this issue, you will want to put in a three way valve after the membrane that is attached to your DI canister.

When you want to make water for your tank, you flip the valve directing water through the DI resin. This way you'll get more life out of your DI.

As mentioned, I'd also check into the pressure and if needed, get a booster pump.

 

[Philliesphan]

It creates a fast flow of water across the surface of the membrane removing deposits which get stuck to the surfaces. It also reduces the concentration of salts in the housing. That can occur when the system is not in use.

Gotcha okay. I will be looking into this. Outside of this, would a second DI filter be a good idea? I saw some people did that.

 

[Glenner’sreef]

Gotcha okay. I will be looking into this. Outside of this, would a second DI filter be a good idea? I saw some people did that.

I have a 5 stage rodi. One of which is the di filter. This system produces the water for my 180g reef full of sps (40ish). Do you have a water pressure valve on your system. That little gauge can quickly indicate when you need to change your filter cartridges and or membrane.

 

[Philliesphan]

I have a 5 stage rodi. One of which is the di filter. This system produces the water for my 180g reef full of sps (40ish). Do you have a water pressure valve on your system. That little gauge can quickly indicate when you need to change your filter cartridges and or membrane.

I don't. That would be something else I need to get.

 

[Spare time]

When flushing, its a good idea to bypass the DI resin. This makes resin last MUCH longer.

 

[Philliesphan]

When flushing, its a good idea to bypass the DI resin. This makes resin last MUCH longer.

So pretty much take the di off, flush it and put it back on?

 

[Spare time]

So pretty much take the di off, flush it and put it back on?

That or make a bypass with a valve and a y connection.

 

[Philliesphan]

That or make a bypass with a valve and a y connection.

Okay I saw a video that said to remove the flow restrictor so I did. And ran the water for 30 mins. Outside of this at the moment, I'll have to wait to get a valve. It's frustrating