DI filter replacement so soon?

[cmgarcia]

Jim, I just started using my unit a few weeks ago. I've made maybe 100 gallons of water and the DI cartridge has turned light brown over half the length of the cartridge. I assume this means its half way spent. Should I change the cartridge when its all brown or wait until I start getting non-zero tds reading. I have an Ocean Reef +1.

Thanks,

Carlos

[AZDesertRat]

Color is a quick guide only and not a reliable indicator, go with TDS readings.

[Thefilterguys]

Carlos do you have your TDS meter hooked up to your DI in and out lines? What kind of a reading are you getting? Are you on the city municipal water system? It is possible you are having a CO2 issue any idea what the pH of your water is?

Jim

[cmgarcia]

Jim, yes I do have the TDS meter hooked up. It has read between 5 to 10 pre-DI and 0 ppm post-DI. Yes I am on city water. My test kit is on order so it will be a few days before I can report PH.

Is it possible that I will need to be changing DI filters so soon?

Carlos

[Thefilterguys]

I looked at your municipal water report again and calculated your CO2 levels and they come out high plus your water is very hard.

Jim

[cmgarcia]

....thats disappointing. I wish I would have known that before the purchase.

What is the replacement cartridge to buy for the Ocean Reef +1? Also, would you consider the output of the RO reef quality without the additional DI stage?

Carlos

[Thefilterguys]

We are usually more focused on disinfectant and most water reports don't list details to calculate CO2. I spent an hour on the phone to come up with the details and calculations to figure your CO2 levels.

The refills for the DI are $12 or four @$42 high CO2 is an issue alot of people deal with. See how much water you get before you start getting a reading from your production water at which time you want to change resin. Even if you only use RO water in the end it will be much better then tap water. In most cases all you get from your LFS is RO water.

Jim

[cmgarcia]

Thanks Jim. I appreciate the work you did to figure out the CO2 level in my water. I'll monitor the output TDS and stretch the filter life as long as possible.


Carlos

[Thefilterguys]

Most water reports do not give the information to figure CO2 levels but your does so it was a good exercise in testing the CO2 calcaulator. I had Boomer from the water chemestry forum help me.

One thing you could do is add a second DI housing to max your resin use but wait to see how long it takes before exhaustion with one housing. Water chemestry is always the unknown factor in RO/DI.

Jim

[cmgarcia]

Thanks Jim. I'll be ordering some refills soon.

Will the elevated CO2 levels reduce the life of the other filters on the Ocean Reef +1 or can I still expect normal life from these?

Carlos

[Thefilterguys]

Carlos the CO2 will only be an issue for the DI resin.

Jim

[cmgarcia]

Jim, as a follow-up to one of your previous questions, the PH of the my DI water is 7.5.

[Thefilterguys]

I don't remember who wrote this but it is a good explanation of why you can't get a good reading of RO-DI water.

RO-DI pH READING

The pH of highly purified water is not accurately measured by test kits, or by pH meters. There are several different reasons for this, including the fact that highly purified water has very little buffering capacity, so its pH is easily changed. Even the acidity or basicity of a pH test kit’s indicator dye is enough to alter pure water’s measured pH. As for pH meters, the probes themselves do not function well in the very low ionic strength of pure freshwater, and trace impurities on them can swing the pH around quite a bit.