RODI issues

[jeremy165]

Hi everyone,

I have a saltwater reef aquarium running for the past 7 years. I'll admit for the last year or so my maintenance and upkeep has been lacking. I just started my own construction company = excuses, excuses...

My kent marine 3-stage RODI unit has suddenly stopped working. Every couple weeks when I need more fresh water, I turn on the water supply, let it run for half the day and my garbage can of fresh water is full. I can then mix to salt or use for topoff.

Recently the unit has slowed down to a dribble. I'm pretty sure its a 60 gallon a day unit but I let it run overnight and I maybe have 8 oz of water if I'm lucky.

I have done nothing to change the RODI setup in months but noticed a week or two ago that the third cartridge had no water in it and was full of air. I let the unit run overnight and this problem somehow disappeared but I still have the problem of no filtered water coming out.

I know that sediment builds up and I may have to change one of the cartridges. What I'm really looking for is to have someone come over to my place in Greenlake/Seattle and walk me through the upkeep of my RODI filtering system, how often to change cartridges, what is currently wrong, and help me make the dang thing work...

For your time and effort I'll let you pick through the approx 40# of liverock I pulled from my tank after aquascaping last night, and you can take one piece. Or let me buy you lunch for your time... Also, I guess I do have some LR for sale at negotiable prices.

But my #1 is getting that RODI unit working again. Please help me, you'll be rewarded!!

Thanks
Jeremy

 

[Scooterman]

You may need to change the Carbon Block cartridge, that is usually the one that stops up fast after the sediment filter.

 

[jeremy165]

Thanks for the help. I assume by the sediment filter you mean the first canister.

I was selling some live rock on craigslist and KC who uses this forum gave me an idea. He said individually, test each canister to see which one is slowing the water flow. So individually, I connected each canister to the supply line, turned on the sink and watched to see water arcing majestically all over my floor until I rushed to turn it back off.

I did this for the prefilter, for the 2nd canister which he referred to as the heavy metals remover, through the membrane, as well as through the final canister containing carbon. Each of these when connected directly to the water supply let loose with a nice stream several feet away from the rodi unit. I was a little excited thinking that maybe when I reconnect the whole unit that there would be a startling change. There wasn't. My maxxima 60 gpd unit which used to overflow my garbage can if I wasn't paying attention now serves up a drip maybe every 30 seconds.

Any ideas? Where do you think my problem is...? I appreciate the help.

j

 

[loohunter]

i would replace all the filters, at least you would know they were all new at the begining of 2009 and replace them every new years. buy them online it shouldn't be to much

 

[Scooterman]

How old is your Membrane? Do you ever back flush it?
The first canister should be your floss filter which would remove the heavy particulates, second carbon, then it should go to the RO membrane & final the DI canister.
What is your water pressure going in to the unit? Sounds like you don't have enough water pressure or maybe also really Cold water will slow down the RO process drastically.

 

[jeremy165]

Things I'm thinking:

I think that my second and third canisters need to be reversed because I currently have an opaque filter in the second canister which I'm thinking is the di resin and I have a carbon in the third canister which I'm now figuring out with everyone's help should be in the second canister.

I don't think I know what backflushing the membrane is. Swap my connections temporarily so the supply is on the normal output of the membrane maybe pushing any caughtup particles off of the normal in side of the membrane?

Water pressure coming into the unit as read by the digital readout is 27 in and 0 out. I know this is low but it has said numbers like these as long as I've had it and only recently have I been having the problem with no water output.

It is wintertime currently (duh) and colder than the summertime (duh^2). Do you get noticably less output during the winter than the summer just because of the lower temperature of water coming in off the main? Since I am using a sink adapter should I turn the hot water on just a little while turning the cold water handle on full just to raise the temp a little and make the unit more efficient?

Thanks for the help everyone.

jeremy

 

[Scooterman]

Here is more information, yes your Di should be last as I mentioned & yes colder water will reduce output.

Filmtec RO membranes are precision fabricated and thoroughly tested to ensure that they provide predictable, trouble-free operation and consistent high performance. They are made to produce the stated GPD at optimum conditions, a water temp of 77 degrees and minimum PSI of 50 pounds pressure. The colder the tap water the lower the water production you can expect. The 75 GPD membrane is a High Rejection (98%) membrane that is standard in all of our systems and produces the highest purity water. Matrikx filters provide you with a standard micron rating and total gallons of chlorine water filtering to take the guess work out of filter changes. We also us premium nuclear grade mixed bed color changing DI resin that changes color as it exhausts. The total package provides you with the assurance of high quality water to enhance your saltwater experience.

Read up all the information you need is here!
That is very low pressure, probably as the membrane gets older & sitting up, it probably is not enough pressure to make it work anymore also colder water. You need more pressure for sure & most probably a replacement RO. I'd call the guys at this web site & talk to them directly, they have great service!

http://www.thefilterguys.biz/