New RO/DI Filter

[Reef-junky]

I have this system and added a di bypass as Opus described, but no other flushing mechanism.

A flush kit just lets the water go to the waste side of the RO. That gives the water a path of less resistantes to go to so it doesn’t go through the DI. A flush kit is not really bypassing the DI. What you are calling a bypass is a flush kit. Yes it flushes TDS creep out of the waste section as well which helps make the Di last longer. Every time you open the valve rather you want to or not you are flushing the membrane.

 

[White Hair]

Before and after every use. The purpose is to prevent scaling on the membrane and make it last longer. That’s the most expensive filter on the whole unit.

thanks

 

[White Hair]

I have this system and added a di bypass as Opus described, but no other flushing mechanism.

where did you get your di bypass

 

[Cell]

 

[White Hair]

Depends on how the terminology is being used. Many now refer to it as a by-pass to the di unit. When you start up the unit each time, there is what is called "tds creep" which means the product water coming from the ro unit will be very high in tds. The flush kit allows you to divert this water from the di canister to the waste line so you are subjecting the di to this high tds water. You divert it for a few minutes until the ro membrane has returned to normal production and then switch it back to the di canister.
If flush kit is referring to flushing the ro membrane, then in my opinion and many others, this is just useless at the consumer level. Until there is some proof that it actually works, I'm not wasting time and water on it.

The rule of thumb for replacing filters is every 6ish months for the sediment and carbon filters. Replace the di once your tds is more than 0. Replace the ro membrane when it no longer meets your personal efficiency threshold. Most are rated at 95% or better. Mine is currently working at 99%. I will probably replace it once it gets to 98%. To calculate your efficiency, you need to know your tap water tds and then your tds after the ro membrane but before the di. My tap is 450 and my tds after the membrane is 4, so I'm looking at .9% of the tds being left. That means it is running at 99.1% efficiency.

little confused abut flush kit vs bi pass, what is the difference and what does each do and do i need one or the other or both, thanks

 

[lapin]

Flush Valve:
What you want is to run water thru the RO filter without restriction on the output end of that filter. This will flush the particles stuck on the outside of the filter membrane. A flush valve allows this to happen by a turn of the valve (open) . With it (closed) it restricts water output via a capilary, so some water is forced thru the membrane.

Bypass Valve:
Goes between the good RO output and your Di resin. This allows you to make water as normal in the closed position. With it in the open position it diverts water before the DI canister. This way any high TDS water will not go thru the Di resin. Can help save on resin. This is done a min or 2 when first making water each time as stated above.

Disclaimer: I dont use a bypass but do use a flush valve.

 

[Opus]

little confused abut flush kit vs bi pass, what is the difference and what does each do and do i need one or the other or both, thanks

It is up to you. The bi pass can increase the di life. If you are making water every couple of days, this may make a difference. If you are doing it every 2 or 3 weeks, maybe it really doesn't matter. Is it worth the time of you turning on the by pass and then remembering to come back in 5 or 10 minutes to flip it back over to the di. Me, I would forget half of the time and come back in an hour to turn of the water and realize all the good water has gone down the drain.

As I stated in my previous post, I believe flushing the membrane is useless. We don't have the water pressure to really make it worthwhile. My membrane lasts 5+ years filtering my very hard 450+ tds water. The extra month of use I might get from the membrane is not worth my time wasted on flushing the membrane over a 5+ year period.

 

[White Hair]

It is up to you. The bi pass can increase the di life. If you are making water every couple of days, this may make a difference. If you are doing it every 2 or 3 weeks, maybe it really doesn't matter. Is it worth the time of you turning on the by pass and then remembering to come back in 5 or 10 minutes to flip it back over to the di. Me, I would forget half of the time and come back in an hour to turn of the water and realize all the good water has gone down the drain.

As I stated in my previous post, I believe flushing the membrane is useless. We don't have the water pressure to really make it worthwhile. My membrane lasts 5+ years filtering my very hard 450+ tds water. The extra month of use I might get from the membrane is not worth my time wasted on flushing the membrane over a 5+ year period.

so in reality, neither is really necessary

 

[Opus]

so in reality, neither is really necessary

Correct. Just possible money saving options. With di around $15 to fill a canister I figure I might save a buck. I figure my time is worth more than that buck.

 

[White Hair]

Correct. Just possible money saving options. With di around $15 to fill a canister I figure I might save a buck. I figure my time is worth more than that buck.

when you say fill a canister do you mean fill or replace

 

[Opus]

when you say fill a canister do you mean fill or replace

I buy the di resin in bulk and refill my canister once it is depleted. I'm not sure if yours can be refilled.

 

[Geonet]

New to this hobby...I'm close to crawling up in the Fetal Position..lol

My RODI comes tomorrow...this post scares me

Geo

 

[Reef-junky]

So people are bypassing the DI. Interesting. Is there an article or something about flushing the RO being useless?

 

[Opus]

New to this hobby...I'm close to crawling up in the Fetal Position..lol

My RODI comes tomorrow...this post scares me

Geo

Most units come assembled so all you have to do is hook it up. Hopefully the instructions tell you to do this, but it is best to run each filter for a few gallons to get out any "gunk" from manufacturing and shipping. So run the unhook the first filter from the second and let it run for a few gallons. Then hook it back up to the second filter. Then unhook the second filter from the RO membrane housing and run for a few gallons. Hook this back up and then unhook the RO output from the DI canister and make around 3 to 5 gallons of water. Hook it back up to the DI filter and you are set. This is assuming you bought a 4 stage unit. Stages should go sediment filter to carbon filter to RO membrane to DI filter. A 5 stage is usually sediment to carbon to carbon to RO to DI.

Before buying a RO unit you really should read your latest water quality report from you water district - assuming you are on city water. You need to know if they use chlorine or chloramines. Chlorine will destroy a RO membrane but chloramines will not but are still deadly to your reef. The carbon is what will remove chlorine and can do chloramines but most people prefer to get a special carbon block that is made to remove chloramines.

 

[Opus]

So people are bypassing the DI. Interesting. Is there an article or something about flushing the RO being useless?

No, I've never seen anything, I'm just going on what I've been told by people in the water purification business. On the opposite side, I've never seen anything to support that it does. I've had my unit for over 25 years and I've changed the RO membrane maybe 6 times. IF flushing only added a couple of months life to the membrane then I don't see the cost benefit of doing it based on the time/water it wastes since a membrane only costs around $40.

If someone were to do a controlled experiment to test flushing and found out it added a couple of years to the life of the membrane then I would agree it was not useless.

 

[Reef-junky]

No, I've never seen anything, I'm just going on what I've been told by people in the water purification business. On the opposite side, I've never seen anything to support that it does. I've had my unit for over 25 years and I've changed the RO membrane maybe 6 times. IF flushing only added a couple of months life to the membrane then I don't see the cost benefit of doing it based on the time/water it wastes since a membrane only costs around $40.

If someone were to do a controlled experiment to test flushing and found out it added a couple of years to the life of the membrane then I would agree it was not useless.

Guess it would depend on what is stuck on the membrane and how hard it is to get it off. Would be a good test for BRS to do.