RO water and slimey bloom

[buildinboats]

I'm having a problem with a clear slime that is clogging up the bottom sponge filter of the post RO deionization cartridge. I have well water and run the RO effluent into a 10 gal hopper with lid that gets aerated vigourously to drive off CO2 before going through the DI filters. At first I used a wooden airstone in the hopper but after a few months it would get a thick covering of the clear slime. I got rid of the airstone, cleaned out the hopper and just have a plastic tube in it's place. I have since found out that the foam filters on the bottoms of the DI cartridges are getting clogged and in the worst case the resin itself is clogging up. Any idea what the slime is and how to eliminate it?

[zigzag1]

My bet is a bacterial growth. Have you ever disinfected your RO unit? You may need to disinfect your CO2 blow-off system too, and continue to do so on a regular basis. A little bleach can go a long way..

http://www.reefcentral.com/forums/showthread.php?t=2023466&highlight=disinfecting+ro

GL!

[disc1]

+1 it's bacterial. And it's probably taking your water the wrong direction before DI. Probably going to need to keep on top of keeping that thing sterilized.

[buildinboats]

I guess I'll need to break down the whole system and sterilize it. Unfortunately this sounds like it will be another ongoing maintenance chore-:sad2:

[buildinboats]

So I got a couple of months out of disinfecting all of the RO/DI components. It's back to where I started, there's a coat of slime on everything and the foam filter built in to the DI cartridge is completely clogged. I'm wondering if installing a UV unit to circulate the RO water in the holding container would kill off the bacteria. It seems overly complicated but it's too much work to be sanitizing everything every other month.

[bertoni]

The RO unit might help, at least for a while. If the bacteria is growing on surfaces, though, the UV won't effect it once it attaches.

You could consider trying a bit of bleach or a bit of salt in the water. They will consume some of the DI, though, and I'd consider adding a dechlorinator to the DI water if I used bleach.

[buildinboats]

How about using the UV sterilizer in line just upstream from the DI. Certainly the flow rate is slow enough. However, the "dead" bacteria would still clog up the foam filter on the bottom of the DI cartridge. I would need to have a particulate filter after the UV sterilizer. I wonder where the bacteria is coming from in the first place, it's either coming form the well water and getting past the RO membrane which seems unlikely or it is airborne, either from the airline I have bubbling in the reservoir or just from contact with the surrounding air.

[disc1]

Check out this link.

http://www.liquicel.com/uploads/documents/Membrane%20Contactors%20-%20An%20Introduction%20To%20The%20Technology.pdf

I know a company called Liqui-Cel makes them. It allows you to use vacuum against a continuous flow of water to degas it. The membrane is hydrophobic and water can't cross, but CO2 can and the vacuum drives it and carries it away.

It might not be too expensive to try.

[buildinboats]

Interesting technology. I could replace the air pump with a vacuum pump plus the contactor and eliminate a possible source of contamination.