I may have found the culprit to my hair algae.

[z28pwr]

This morning I was wondering why my RO was taking so long to make water and I took a look at the DI membrane and it was redish and very ugly looking therefore I wiped the dust off the TDS meter and measured a whopping 22 TDS out of the RO/DI unit :shock: . I guess these things need to be changed out sooner then after 600 - 800 gallons of production water.

I called AQRS and they suggested increasing my RO/DI from a 4 stage to a 5 stage so that I can swap DI cartridges since my incoming water is 325 TDS and I also ordered another Carbon, Sediment and DI cartridge.

I hope this was the culprit although I feel dumb since Ken had already told me to check my RO unit :roll: .

Looks like I'll have to change my DI cartridge soon after I fill up my 375 since they recommend swapping them out every 400-500 gallons. I'll just have to check and see.

[z28pwr]

Check your RO (before DI) water to make sure your membrane doesn't need a swapping. If your membrane is putting out high TDS it'll waste your DI in no time flat. I had calcium deposits that killed my RO membrane and in turn killed the DI so had to replace them both.

Not what I wanted to hear. I had to replace the water heater cores due to calcium deposits and the house isn't even 2 years old. Man I regret not getting a water softner. It would pay itself in just a few years.

I'll check out the membrane.

I tested the water directly out of the RO/DI, not mixed with the old RO/DI water and it was 22 TDS stil not good at all. I'll check what it is after the RO membrane before the DI cartridge.

[Instar]

What are you guys doing and how are you making it? You should be making DI first, then running through the R/O membrane. Di water is from a resin based filter that is after your 1 micron sediment filter and before your R/O membrane.
Di water is a little better than what you get with a good softwater system. The R/O membrane is the one that will burn on you if you don't clean up the water first with all those other towers. (BTW, this is part of what I do for a living). You should get a long time out of an R/O membrane - as in years, not gallons, even with the high TDS of the aquifer water. You may need to add a reverse flush kit to your system to keep it clean, if you don't already use one.

[z28pwr]

Larry as Josh said if you put a DI before an RO your DI won't even last 10 gallons. Just because it's on top doesn't mean it's the last step.


Checkout the schematic for a 4 stage RO/DI unit.

http://www.aquaticreefsystems.com/images/StandardOceanusdiagram.gif

You will notice that the first stage is Sediment, Then Carbon, Then it goes into the RO membrane and finally to the DI.

[z28pwr]

This is how it will look with the additional DI cartridge.

http://www.z28pwr.com/images/newrodi.jpg

[Instar]

Very interesting. I guess I'm used to commercial sized stuff. My lil R/O is about the same, except I don't DI mine at all. I have no appreciable hair algae. My aquifer is a little different thought too. I'm connected to the upper Carrizo-Wilcox and have a TDS of 500 incoming when it doesn't rain a lot. The only thing I really want out of the water is the copper, lead and chlorodibromomethane (and possibly odd unknown stuff). In large systems, its the softeners and other filters/resins, then DI resin towers, then the R/O is last for a 99.9% pure reagent grade (ACS Standards) water. With that diagram your statement to check the water between the R/O and Di makes total sense. Thanks.

[Instar]

35 beats the living tar out of my start at 500. I should test it to see what the 35 or whatever mine is, has in it.