R/O holding tank

[brianbell1]

Hello, I need a littl e advice if anyone can help. I currently have a whole house RO unit with only a 3 gallon holding tank. I was looking to add more holding capacity by adding a larger tanks to the system. The tanks are designed with a rubber bladder to pressurize them and I found the R/O dealers charge a fortune for a decent sized holdiing tank. My goal is to have 10 to 15 gallon made at a time so when I do a water change it will be ready to pump right through the DI filter and into my mixing container. I noticed the expansion tank on hot water heaters works witht the same principles and are much cheaper. I purchased two 5 gallon tanks from the local plumbing store for $25 each.
I read on an R/O dealers site that expansion tanks cannot be used. I am waiting to hook them up until I am possitive I cannot use them
If anyone knows if this is correct and why they cannot be used I would appreciate the info.
Thanks in advance for the help.

 

[stanlalee]

I cant help you but I know what you mean. I have a Hydrotech unit that was already installed with sink faucet before I bought my home. I start filling 5 gallon buckets with RO water a week before I do my water change. I can only get about 2.5 gallons before I have to wait seems like half a day before there is significant reserve to start filling again. Good thing I only have a 30 gallon tank.

 

[birdy]

Well I am not sure how it would work if you use the RO for your drinking water, but for my RO/DI units for my fishtanks I have a food grade 55 gallon drum that I use, I just hooked up a float valve to the bucket and there is a shut off valve for the RO unit.

 

[scsinet]

I use a Rubbermaid "BRUTE" 33 gallon plastic garbage barrel. It's dirt cheap and available anywhere. I built it on a 2x4 stand and installed a PVC bulkhead and ball valve at the bottom so I can set a 5gallon bucket underneath and fill it to mix seawater. The whole thing sits in a corner of my garage.
With that much size, you can manually control the RODI unit, as long as you don't forget and leave it running overnight........
That's what I do, but I want to go to the float valve when I'm not too lazy to install it.
Be sure to drop a small powerhead into the storage container and keep it running so the water doesn't get stagnant. If it's in the garage, it probably won't freeze unless you live in Alaska, but you'll want a submersible heater around for when you do changes to heat the water up.
...oh yeah, and to use your RODI unit for both, you can get a little 1/4" compression "T" fitting. Just install it somewhere's after your RO unit but before the storage tank. You can also get a little inline 1/4" compression ball valve (PVC, not copper obviously) to control your storage tank level.