RO/DI

[Bosco83]

My ro/di filters don't look dirty but the water coming out is now 13 tds. Should I still change all the filters or just the di? The filters are about 5 months old but have only made a couple of hundred gallons I think.

Thanks,
Brian

 

[Myteemouse]

sounds like it may be your membrane?

 

[cdbdis]

Not sure what kind of setup you're running. If you're running a prefilter, I'd be inclined to change that out first and see if your TDS begin to drop - I'd also consider changing out your DI resin filters first if you're using them. 200 gal is not a lot of production to get out of a membrane, however membrane life is largely dependent on your water quality.

 

[sandswhitson]

I would change all the filters just to be safe. If the prefilters are getting bad then they will allow chlorine thru and that will ruin your membrane. I don't think your membrane is bad probably just time for a filter change. I get about 20 TDS after my RO and then 0 after the DI.

 

[Scooterman]

Depending on your water quality going in can determine what your going to use up the most. First I'd check the TDS meter your using against another or recalibrating it. Then look at production rate, if it isn't decreased I'd replace the DI. Do you have color changing DI? I would not buy a new RO membrane, these should last you several years.

 

[Bosco83]

Sorry I should have given a little more info. The unit is a 100gpd air water and ice. I bought it used and it came with all new filters so I replaced them to start fresh. The girl I bought it from said it was still putting out 0 tds when she took it down and the old filters were way dirtier looking then mine now. my water going in measured about 35 tds a few months ago and now says it is 40tds. my DI filter pretty much all turned orange so I think that means to replace it. I heard that Home Depot sells the filters but do they sell the di one?

Thanks,
Brian

 

[DolphinLVR]

Sorry I should have given a little more info. The unit is a 100gpd air water and ice. I bought it used and it came with all new filters so I replaced them to start fresh. The girl I bought it from said it was still putting out 0 tds when she took it down and the old filters were way dirtier looking then mine now. my water going in measured about 35 tds a few months ago and now says it is 40tds. my DI filter pretty much all turned orange so I think that means to replace it. I heard that Home Depot sells the filters but do they sell the di one?

Thanks,
Brian

I would contact Air, water & Ice. From what I understand, they have great customer service and will support the unit even though u bought it used.

 

[cdbdis]

If you were running 35TDS after all new filters then I would definitely consider replacing the membrane. With no way to really know how much water went through it before you bought it - it's the only way to be sure. Also, I think 35 TDS is quite high for putting water in a reef tank. As a point of reference, with my spectrapure unit I will change out a membrane if my TDS on my final outlet reads 1ppm or greater after changing filters. Being on well water where I am, there's a tendancy for ca+ to precip out...even with the backflush rig. Membrane's can be had fairly cheap - I buy mine direct from the manufacturer when on sale for around $40. Lasts about 2000 gal...even with my hard water.

 

[Bosco83]

If you were running 35TDS after all new filters then I would definitely consider replacing the membrane. With no way to really know how much water went through it before you bought it - it's the only way to be sure. Also, I think 35 TDS is quite high for putting water in a reef tank. As a point of reference, with my spectrapure unit I will change out a membrane if my TDS on my final outlet reads 1ppm or greater after changing filters. Being on well water where I am, there's a tendancy for ca+ to precip out...even with the backflush rig. Membrane's can be had fairly cheap - I buy mine direct from the manufacturer when on sale for around $40. Lasts about 2000 gal...even with my hard water.

No my regular tap water is 35

 

[Kurt_Nelson]

If your tap is 35ppm, and you're getting 13ppm out, then it sure sounds like the membrane. Easiest way to check is take a sample after the RO, but before the DI.

The other thing that might be happening is that your DI is completely exhausted and is now leaching stuff back into the pure water, bumping up the TDS.

Either way, taking a TDS reading between the RO and DI stages should clear up what the problem is.

 

[royalreef]

Ok I have a diferent question. I barely installed my RO/DI system and from the hose that it was suppose to be the filtrered water it is really dirty and from the other end the water is clear is my system ok? also the "clear" water is dripping and dirty and the other end is alot much flow. the lady that I bougth it from say that it waste water was too much and she sell it for $40, a 5 stage system with new filters. so this is kind of stupid but I had never used a RO\DI system so the big flow is the filtered water or is the one that is dripping?

Thank you and sorry for the stupid question.

 

[Bosco83]

Ok I have a diferent question. I barely installed my RO/DI system and from the hose that it was suppose to be the filtrered water it is really dirty and from the other end the water is clear is my system ok? also the "clear" water is dripping and dirty and the other end is alot much flow. the lady that I bougth it from say that it waste water was too much and she sell it for $40, a 5 stage system with new filters. so this is kind of stupid but I had never used a RO\DI system so the big flow is the filtered water or is the one that is dripping?

Thank you and sorry for the stupid question.

The waste water will be the one that is flowing a lot and the clean filtered water is the one that is dripping.

 

[Bosco83]

If your tap is 35ppm, and you're getting 13ppm out, then it sure sounds like the membrane. Easiest way to check is take a sample after the RO, but before the DI.

The other thing that might be happening is that your DI is completely exhausted and is now leaching stuff back into the pure water, bumping up the TDS.

Either way, taking a TDS reading between the RO and DI stages should clear up what the problem is.[/QUOTE

I will take a reading before the DI and see what it is when I get a little more time.

 

[royalreef]

The waste water will be the one that is flowing a lot and the clean filtered water is the one that is dripping.

but is normal that the water is orange>?

 

[Scooterman]

Ok, the Di is Orange then it is considered Used up, it is normal to get a 98% rejection rate from the RO membrane, you will not get 0. The DI will polish off the rest of measured TDS. So replace that first, If you continue to use up the Di then you may need to go to a second DI. I would check the TDS after the RO, you should get about a 98% rejection.

 

[Bosco83]

Today I checked my tds straight out of my tap water and it is reading 25. I checked it after some di by-pass vavle and it is still reading 25ppm? So I checked it after everything and it says 12ppm. Now it sounds like my membrane might be bad right? or the valve isn't really filtered water at all since it didn't even drop it at 1ppm.

Brian

 

[sandswhitson]

Have you checked the TDS after the RO and before the DI? The DI cartridge could be so fouled that it is releasing stuff back into the water.

 

[Bosco83]

Have you checked the TDS after the RO and before the DI? The DI cartridge could be so fouled that it is releasing stuff back into the water.

That what Is what I was trying to say I have a valve that is supposed to be ro filtered water but before the di filter for drinking water and it was still 25ppm.

 

[sandswhitson]

I would say that if your tap is 25 and your RO is 25 as well then you need a membrane.

 

[burning2nd]

Ok, the Di is Orange then it is considered Used up,

ive talked to the filter guys and a few other manufacters of the Di resin... and it turns out that just cause it turns a different color does not mean that its wasted....

i figured this out after haveing a few brand new Di carts turn brownish with in a few days of installing... thinking something was wrong i changed all the filters and the ro... checked everything and still happened ageain..

turns out that CO2 is what makes the color changeing DI cart's change color
so just cause mine were changeing with in a few days of installation didnt mean they were bad..

you should referd to your duel Tds meter... checking what goes in and what comes out.


altho i was unable to figure out what i was geting a larger then normal amount of co2 thur the water or makeing it past the filters the color didnt effect the overall equipment effectiveness