TDS

I let my RODI filters go to long last year and it may have contributed to a mass die off of SPS corals. IMO, it is a good idea to do regular maintenance on the pre filters and always have extra sediment and carbon filters on hand.

Are the sediment filters clearly dirty? If you wait to long to replace them your pressure to the membrane will drop and cause a reduction in performance.

How about the carbon filters? If not changed on a regular basis they will be rendered as in effective at removing chlorine which in turn will ruin your RO membrane.

I would start with the sediment and carbon filters, if that doesn't help replace your membrane.


Be sure to order extra filters for your first stage as they will always need to be changed out more frequently than the others

HTH

 

The DI resin wears out first. My TDS for my BRS 4 stage unit was 0 for a lot of water, but not a long time. Our water in Marion is showing 380-450 TDS incoming on any given day and that is after my water softener. Coming out was 0 like I mentioned, but as the Di resin starts wearing out, that has crept up to a TDS of 2 coming out. I have a FOWLR tank, so I am technically OK, but I am going to change my resin this weekend. I've heard other FOWLR people go as much as about 4-5 TDS. For reef, you want 0. Resin should run about $10 or so for a refill amount. Don't worry about the color changing stuff. I had that, and it went from blue to brown LONG before my TDS ever started to go up.

If there is clearly visible sediment like Waverz mentioned, then those filters should be replaced. BRS has a full kit that does everything but the membrane for a pretty good price. Then you know where you sit, and can change out carbon about every other resin refill, and then do the sediment one as you see the build-up.

Don't forget to flush the membrane. If you don't have a flush kit, order one form BRS when you get the resin. It take 1 minute to add it and it will help clean your membrane.

 

I never understood why on a duel TDS meter u measure the TDS of incoming water?
we all know it's high right.
So I actually put the incoming probe after my RO membrane this way I know if my membrane is going
bad. usually reads about 10ppm after membrane and 0ppm after my DI.
and +1 to what wavers said.

 

Correct. The first probe should go before your resin (after the membrane) and the second should go after the resin. I bought my RO/DI unit used from another GIRS member, and the first TDS meter probe was measuring the water before any filtration, thus the reason I know where my house's water it. I have sense moved it to a location that makes sense.

As for reading 10 ppm after the membrane, that doesn't seem all that bad to me. The resin should be, and is cleaning the rest.

 

Measuring the incoming water before the sediment and carbon filter can be used to see how those are functioning and what the TDS is before the membrane. I use 2 dual meters ...H20 coming in, after the prefilters/before the membrane...after membrane/before DI resin...output /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif I don't have to guess when the prefilters are getting dirty /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif

 

Sponge: Nice!

Looks like about $30 to add another 2 probes. Hmmmm....

 

That is a great idea Sponge. I will have to piggy back on that idea. Truly will take the guess work out.

 

This is a good idea. My unit has a pressure gauge before the membrane. When is see that level drop I knoe its time to change pre filters.
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