karimwassef
Active member
Also, when you replenish, do you purge the old white mud completely?
Kalkwasser going bad in reactor?
- Thread starter jccaclimber
- Start date
jccaclimber
Member
RO, not DI. This is the first time I've had to replenish and I did clean it out.
jccaclimber
Member
Is there that much CO2 even after a couple weeks of sitting there? My RO goes into large storage containers where it sits. I do not have the RO line plumbed in to ATO. That may still be the cause though as I remember the DI going quickly the time I hooked it up. Is pH out if the RO filter, then again after degassing and acceptable way to estimate dissolved CO2?
If the water is aerated for a few hours, especially outside, it will outgas carbon dioxide if it contains more carbon dioxide than the equilibrium level with the air. The water always will have some carbon dioxide, in your situation.
Measuring the pH of RO water accurately is difficult for reasonable TDS levels. Technically, I don't remember how to do it. If the DI media was being exhausted rapidly, and the TDS out of the RO was reasonably low, the issue might well have been carbon dioxide. I have forgotten how strongly carbon dioxide ionizes in water. Is this well water?
Measuring the pH of RO water accurately is difficult for reasonable TDS levels. Technically, I don't remember how to do it. If the DI media was being exhausted rapidly, and the TDS out of the RO was reasonably low, the issue might well have been carbon dioxide. I have forgotten how strongly carbon dioxide ionizes in water. Is this well water?
jccaclimber
Member
City provided water in Murphy (Dallas), TX. Surface lakes are the local source. It's also worth noting that at the time I was changing 300 gallons of fresh water in another tank every 1-3 weeks, so "quickly" was probably 600-1000 gallons of RO/DI. On the other systems I deal with that would be many months worth, so it may just be a function of throughput. Really I should probably have a DI for the reef and non DI for the planted tank, but that's more containers and a separate discussion.
Is there something about low TDS water that makes pH probes (or less accurately bromothymol blue) inaccurate?
Is there something about low TDS water that makes pH probes (or less accurately bromothymol blue) inaccurate?
I'm not sure how much carbon dioxide would be in your water. You could take a small sample, measure the pH, and then aerate it for a few hours outside. If the pH rises much, then I'd suspect there's a lot of carbon dioxide in the water.
pH meters don't work in RO/DI. Even RO might be suspect. One problem is the lack of buffering, which means that the pH can shift quickly, and possibly even be influenced by the probe itself. That's why the pH test kits are unreliable. I don't know the details. We could look up some reading, if you're interested.
pH meters don't work in RO/DI. Even RO might be suspect. One problem is the lack of buffering, which means that the pH can shift quickly, and possibly even be influenced by the probe itself. That's why the pH test kits are unreliable. I don't know the details. We could look up some reading, if you're interested.
Similar threads
