RODI with High Rust Content Water

[AZDesertRat]

Adding additional filters has its drawbacks, mainly its that each filter or component in front of the membrane has an associated pressure or head loss so reduces the pressure available to the membrane which reduces its efficiency. The more pressure you can supply the membrane the higher its rejection rate or removal efficiency will be. The more efficient the membrane is the longer the DI will last, etc. Its all about cost of operation and ownership.

 

[cdness]

Ah ha! Sell it is then

I'll need to figure out which sediment filter and dual carbon blocks to fill my canisters then. Any recommendation on the carbon blocks? My current one is a 1 micron and a .6 micron I believe. For sediment I'll go with the good pleated one.

 

[AZDesertRat]

Keep the 0.6 micron carbons and sell the others. A 1 micron is good for 12,000 total gallons of water, a 0.6 or 0.5 are good for 20,000 gallons of water and protect the membrane from particulates and colloidal materials that much better.

 

[cdness]

So I'll be looking at the following config (in the order of water flow):

.5 or .2 micron Sediment filter
.6 Carbon block
.6 Carbon block
Dow Filmtec 98% rejection membrane
MaxCap DI
SilicaBusterDI

After this change I am out of filters anyway. All I had left are sediments as I ordered a TON because of my water. Is there a specific carbon block you'd recommend?

Also do you think I should use the back-flushable sediment filter as well or just leave it out? I don't really want to wreck the more expensive sediment filters just a quickly as my cheap ones if I am getting a smaller micron and no softener in the plans again...

 

[AZDesertRat]

If you have the backflushable prefilter use it. It waill as you say extend the life of your sediment filter. I would not use two carbons though as this is old old technology going back when carbon was not what it is today. many ebay vendors still use two to make up for low end, low capacity or coarse carbon. Notice companies like Spectrapure, Buckeye and PurelyH2o only use a single high quality carbon. Its all you need.
You could easily convert the extra empty housing to a vertical refillable DI then you would only need to add one additional canister to get your Dual DI. That or just remove it from the array and have a spare canister.

 

[cdness]

So you're saying do it this way:

Backflushable Sediment
.5 or .2 micron Sediment filter
.6 Carbon block
Dow Filmtec 98% rejection membrane
MaxCap DI
SilicaBusterDI

I don't have the back flushable sediment filter yet. I figured it may be a worthy investment, but maybe not. Opinions?

Maybe I can just get a larger metal bracket and rebuild it all to be on a single bracket... Either that or just remove the second carbon block and have a spare housing. I know it is all hard plumbed so I'll need to do some modification, but that's never been an issue for me

Do carbon blocks or sediment filters have a shelf life? Probably a dumb question but I figured I'd ask anyway.

Thanks for all the help with this. I really appreciate it.

 

[AZDesertRat]

Yep, thats the order I would run them in. The backflushable filter wil probably need a bracket of its own as it has some extra plumbing but you could get a 4 place bracket for the sediment, carbon, membrane on top, DI, DI arrangement so it looks clean. As far as plumbing most vendors use nylon or plastic nipples or John Guest speed fittings either straight or 90 degree between the lids so its easy to reconfigure things.

 

[cdness]

My BRS unit is hard plumbed to each canister with threaded pipe. I'll need to get some more of the nipples and just reconfigure it on my own. No biggie as Lowes has the John Guest fittings.