Do I need an RO/DI booster?

[sreed07]

So I e got the RO/DI unit that generally sits around 50 PSI. I got it second hand and don’t know the exact specs on it, but it pump out roughly 1 gallon every 7 minutes. Comes out 0 TDS and my last resin pack made between 300-400 gallons. My question is, does it really need a booster pump? I know they say that 50 psi is low but it seems to be to be working fine. Thoughts?

 

[stanlalee]

If your getting a gallon every 7 minutes out of a single membrane kit WITHOUT a booster pump I'd be questioning why its working so fast. I have a booster pump and produce about 1 gallon per 9 minutes with optimal temps which is well above the 100g/day spec. In colder temps I get a gallon every 11 minutes which is still more than spec. That's at 95 psi.

 

[sreed07]

If your getting a gallon every 7 minutes out of a single membrane kit WITHOUT a booster pump I'd be questioning why its working so fast. I have a booster pump and produce about 1 gallon per 9 minutes with optimal temps which is well above the 100g/day spec. In colder temps I get a gallon every 11 minutes which is still more than spec. That's at 95 psi.

Is there a bad thing about working that fast? Something I should be concerned about?

 

[Eagle_Steve]

Is there a bad thing about working that fast? Something I should be concerned about?

Do you know your tds before any filtration and after your ro membrane but before the di resin? If you have soft water and low tds, you may able explain why you can make more on a lower psi.

For example, my tds is 34 before, 1 after and 0 after di resin. I have a 500gpd system and can easily make close to 650 at 95 psi. I made almost 550 a day at 55 psi before I got the pump.

 

[sreed07]

Do you know your tds before any filtration and after your ro membrane but before the di resin? If you have soft water and low tds, you may able explain why you can make more on a lower psi.

For example, my tds is 34 before, 1 after and 0 after di resin. I have a 500gpd system and can easily make close to 650 at 95 psi. I made almost 550 a day at 55 psi before I got the pump.

Been a while since I tested, but I think it was about 150 going in, 10-15 after RO and 0 for the final

 

[Eagle_Steve]

Been a while since I tested, but I think it was about 150 going in, 10-15 after RO and 0 for the final

That’s only 90-93%. Booster would probably get you to 98-99% and would create less waste water. Your resin would also last a very long time.

 

[Greg P]

What's your tapwater TDS?
Is the 50psi source or post membrane?
How much waste to filtered water do you get? Such as 4-1 or so ...

 

[Reef.]

Been a while since I tested, but I think it was about 150 going in, 10-15 after RO and 0 for the final

should be less than 10 before the resin if that is what you meant, you should be aiming for around 2 at the most

You don’t say what your membrane is rated at? If it’s a 150gpd membrane then you are good, if it’s less than 150 you may have an issue.

 

[sreed07]

What's your tapwater TDS?
Is the 50psi source or post membrane?
How much waste to filtered water do you get? Such as 4-1 or so ...

Tap water is around 150. I’m not really sure where the gauge is reading the psi honestly. Waste is about a 1.5-1

 

[sreed07]

should be less than 10 before the resin if that is what you meant, you should be aiming for around 2 at the most

You don’t say what your membrane is rated at? If it’s a 150gpd membrane then you are good, if it’s less than 150 you may have an issue.

Alright just tested them all. Tap was 138, RO was 15. RO/DI was 0. 55 psi

 

[Reef.]

Alright just tested them all. Tap was 138, RO was 15. RO/DI was 0. 55 psi

You still haven’t said what rate your membrane is?

 

[sreed07]

You still haven’t said what rate your membrane is?

I don’t know what it is, guessing I’ve got to take it out to find out? Still new to the hobby

 

[Reef.]

I don’t know what it is, guessing I’ve got to take it out to find out? Still new to the hobby

yes but don’t unwrap it, should be on the blue part, or check where you bought it and see what you bought, that figure is important as it’s the speed the water is allowed to pass through the the membrane is what gives you your production rate, so a 75gpd membrane should produce 75 gallons a day, if you know that figure you will know how well your system is working.

 

[sreed07]

Ok I’ll go look. Guessing it’s the very first one?

 

[Eagle_Steve]

I don’t know what it is, guessing I’ve got to take it out to find out? Still new to the hobby

Do you see a flow restrictor on the waste line? It may look like a large round tube? If so, it will have a number on it. 500 or 800 for example.

 

[Reef.]

Ok I’ll go look. Guessing it’s the very first one?

No it’s the one on the top, pull it off and unscrew the end, pull it out but don’t open up the membrane, it should be written on the blue plastic (might not be blue)

 

[sreed07]

Do you see a flow restrictor on the waste line? It may look like a large round tube? If so, it will have a number on it. 500 or 800 for example.

Yes, 500

 

[Reef.]

Yes, 500

500 was on the membrane?

so are really low then, you are only just making 150galloms, when you should be producing 500. So yes a booster will help and it will only help get your 10-15 down to around 2 before the resin, the lower the number before the resin the longer the resin will last.

 

[Eagle_Steve]

Yes, 500

That is typically used on a 75gpd system. That doesn’t mean much though, as I have seen people use 150gpd membranes with a 500 flow restrictor.

I agree with @Reef. and you need to check the membrane for a number or gpd listing on it.

 

[Eagle_Steve]

500 was on the membrane?

so are really low then, you are only just making 150galloms, when you should be producing 500. So yes a booster will help and it will only help get your 10-15 down to around 2 before the resin, the lower the number before the resin the longer the resin will last.

I think he was answering my question on what ml the flow restrictor was. At least I hope so lol.