DI replacement questions

[mkengr45]

is this
http://www.purelyh2o.com/cart.php?target=product&product_id=79&category_id= 24

and this
http://www.purelyh2o.com/cart.php?target=category&category_id=25

an alternative for this

http://www.purelyh2o.com/cart.php?target=product&product_id=25&category_id= 14

also I am using a Coralife version of this
http://www.purelyh2o.com/cart.php?target=product&product_id=17&category_id= 13

and am unsure which of these things is bad. My TDS is about 25 and I am thinking it is the little blue cylinder thing, but am wondering if that blue thing is dead if my mixed bed thing is also dead. I hhave only put about 100 gallons through this thing since it was new, but I didnt do any flushing and am wondering if that is why my TDS sucks. let me know folks....

Randy

[mkengr45]

I looks much cheaper for me to get the refillable cartridge and a bag of the resin instead of getting the blue tube thing, assuming they are doing the same thing. My mixed bed cartridge has orange/brown sand-looking stuff in it, what are your thoughts on this thing being bad. Is it most likely the blue tube thing or the mixed bed thing

[matt]

The blue tube thing is your R.O. membrane, which is different than the D.I. cartridge. The R.O. membrane on your filter should be horizontal, sitting above the 2 vertical canisters which should hold a prefilter and a carbon block. The flow from your faucet should go into the prefilter, then into the carbon, then the R.O. membrane. Coming out of the R.O. membrane is a waste hose and an output hose. The output hose should have 10% or less of the TDS that your source water has; 25ppm TDS is about right for tap water in San Antonio.

Then to get to zero TDS, you go from the output of your R.O. membrane into the D.I. cartridge. The 1st 2 products you listed are the best way to refill your D.I. cartridge.

Expect to get a couple hundred gallons from a D.I. cartridge; any more and it will be exhausted. If your R.O. was not functioning, meaning if you were sending 200 ppm TDS to the D.I., it would still get the water close to zero but would get used up MUCH faster. The other thing to watch out for is make sure that your carbon block is in good shape, as it removes chlorine which will damage the R.O. membrane.

You might give Bryan at purelyh20 a call. He's very knowledgable and helpful on the phone. It would not be a bad idea to just get all new filters from him; 1 micron prefilter ($5 I think) a new carbon block (not much) and the D.I. stuff. Probably your R.O. membrane is okay, but what you should do is disconnect the line from your R.O. output to the input of the D.I. and test it there. Make sure it's 25 or so at that point. If it's much higher, get a new R.O. membrane too. It's worth testing because that's the expensive one.

[chrismikea]

i would have to tell you to ask seamonkey, he seems to know alot about this stuff

[captexas]

Their are different types of DI resin along with different grades. There is color changing resin which changes color as it is spent to show that it is depleted and needs replacement. Regular/non-color changing resin stays the same color and you need a TDS meter to measure it's output and decide when it's time to replace the resin/cartridge. This is why some peoples resin is different in color than others. Even with the color changing resin I would still recommend using a TDS meter.

[Bill S]

In discussing this with Coralife, they do NOT use the right resin to get you to 0 TDS - that's why their cartridges are so cheap. So, I bought a refillable cartridge for my second RO/DI unit, and put the correct resin in it. I buy mine online from Canada - aquasafe - who made my first unit.

[BuckeyeHydro]

Don't forget: http://www.buckeyefieldsupply.com/showproducts.asp?Category=40&Sub=127