UV sterilization of RODI water

[jokerman826]

Recently I have been noticing on my local reefing FB page people complaining about bacterial slime in their RO containers. I have the same issue.

I was thinking about UV sterilization. Would recirculating RO water through a UV sterilize help prevent the bacteral slime growth? I am thinking it would since UV sterilizers can be used to kill parasites and algae in a tank.

What do the experts have to say about it?

 

[Stevenlburton]

Following

 

[coral49]

sorry can't help, but cleaning my RO brute can this week I've had my 1st experience with the clear slime in RO. I am eager to hear solutions and is it a problem that can impact the tank. Looking to learn more on the whole issue

 

[sbash]

I'm no UV expert, but I did install a UV system on my house a couple years back. Basically, yes, a UV system will destroy the dna of the life going through it. You would also want a real UV system, not just those filter/pumps with a UV light in it (they might help, but probably not as well as you want). The lamp should be enclosed and you would have to pump water through it.

However, a much cheaper way to go would be to not contaminate your reservoir. Now, that might be easier said than done, as the reservoir does need to have an air hole to allow the water to flow properly. I have been using the same reservoir (just a clear plastic bin with a lid) for 3 year and it does not have any sort of build up.

To help address the problem, have you checked the TDS coming out of your RO system?

How many stages in your RO system? (e.g. particle and charcoal before the membrane and DI after)

 

[jokerman826]

I'm no UV expert, but I did install a UV system on my house a couple years back. Basically, yes, a UV system will destroy the dna of the life going through it. You would also want a real UV system, not just those filter/pumps with a UV light in it (they might help, but probably not as well as you want). The lamp should be enclosed and you would have to pump water through it.

However, a much cheaper way to go would be to not contaminate your reservoir. Now, that might be easier said than done, as the reservoir does need to have an air hole to allow the water to flow properly. I have been using the same reservoir (just a clear plastic bin with a lid) for 3 year and it does not have any sort of build up.

To help address the problem, have you checked the TDS coming out of your RO system?

How many stages in your RO system? (e.g. particle and charcoal before the membrane and DI after)

I have 0 TDS coming out of my RODI. 7 stage RODI (Sediment, 2 charcoal, dual membrane, two DI). My idea was to use something like the turbo twist at a very low flow rate (not more than 30GPH). I have had one on my reef for years and never had an issue with it or my tank.

I have a 60 gallon water storage container which is elevated in my garage. It has a small air hole that is sealed by a spring loaded ball. I recently cleaned it and the RO system out and it had a small amount of slime in it. My top-off containers are more open due to hoses and plugs and they have a lot more slime.

From what I understand though, the RODI does not get rid of/kill bacteria (I may be wrong), so there could still be stuff in the water.

 

[Mark Gray]

I have my 100 gallon revivor sealed it has a vent in the lid but so far knock on wood have never had a problem with slime in it

 

[Retro Reefer]

Periodically disinfecting the containers with a bleach/water mixture would probably be more effective than running UV as that’s not going to do anything to the slime bacteria that’s coating containers only free floating bacteria would be affected.. we had this issue with misting nozzles at a company I used to work for. That clear slime can potentially be some nasty stuff and even though the water feed to them was ultra purified through multiple stage carbon blocks, RO/DI and UV we still had the clear slime growth.. a periodic cleaning with bleach solution cleared the problem and slowed down recurrence

 

[Reeferdood]

There is no real evidence that the slime is unhealthy from what I have ever read. My storage containers are slimy and I have never seen adverse effects from it.
The Filter Guys have said in the past that it is normal to have slime in storage containers, so I haven't thought about it since.

 

[Retro Reefer]

There is no real evidence that the slime is unhealthy from what I have ever read. My storage containers are slimy and I have never seen adverse effects from it.
The Filter Guys have said in the past that it is normal to have slime in storage containers, so I haven't thought about it since.

I know less than zero about clear slim bacteria but I do know we where threatened to be shut down by environmental safety inspectors if we didn’t resolve the issue with our misters so I’m assuming it can be potentially be dangerous to humans anyway

 

[Reeferdood]

I know less than zero about clear slim bacteria but I do know we where threatened to be shut down by environmental safety inspectors if we didn’t resolve the issue with our misters so I’m assuming it can be potentially be dangerous to humans anyway

Interesting, I wonder what it is and why it would be bad for misters? Someone out there must know something but this has never been answered on the forums.

 

[jokerman826]

Periodically disinfecting the containers with a bleach/water mixture would probably be more effective than running UV as that’s not going to do anything to the slime bacteria that’s coating containers only free floating bacteria would be affected.. we had this issue with misting nozzles at a company I used to work for. That clear slime can potentially be some nasty stuff and even though the water feed to them was ultra purified through multiple stage carbon blocks, RO/DI and UV we still had the clear slime growth.. a periodic cleaning with bleach solution cleared the problem and slowed down recurrence

In order to get the slime, you will need something free floating. So in theory, if you continuously have the water get hit with UV, you should get rid of any bacteria that would cause the slime. I just did a complete RO system and top off clean out with bleach. We will see how long it lasts.

 

[jokerman826]

There is no real evidence that the slime is unhealthy from what I have ever read. My storage containers are slimy and I have never seen adverse effects from it.
The Filter Guys have said in the past that it is normal to have slime in storage containers, so I haven't thought about it since.

I agree with you, I have not had any adverse reactions.

 

[sbash]

From what I understand though, the RODI does not get rid of/kill bacteria (I may be wrong), so there could still be stuff in the water.

A quality RO membrane should remove the bacteria. RO works by squeezing water through the membrane, thus now allowing particles larger than the pore in the member through. This is why there is so much more waste water than 'clean' water. I'm not really a qualified water system engineer to make this statement, but, unless you have some seriously tiny bacteria in your water system, the bacteria is not likely coming from your source...

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