More Low pH Questions
- Thread starter cameron
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I need to raise pH without raising alk. Most additives (and specifically the ones mentioned in Randy's articles on this subject) raise Alk in combination with pH. I am pretty sure I need to vent CO2 in this case. Kalkwasser can do it, injecting low CO2 air into the water column can help as well but I was hoping for something a little less messy and nasty to deal with. I have a feeling any solution is going to require some messy chemical.
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I know I've seen this a lot with reactors before (at RC threads), and Randy gave them some advice to help. I think it was a combination of dosing part b (alk) along with CO2 adjusting. However, since I only use 2 part, I didn't really pay attention that much. I still say you should ask Randy though. It couldn't hurt.
Yes and no: You are right in that as long as the tubing can handle the flow, the back pressure should be low (though you need to add any "head" pressure, if you pump it very far vertically.. a problem when I was pumping from the basement to my tank). Where you really run into problems is when the tubing gets clogged up. That can happen on Kalk systems, especially where it exits the tubing. I blew the tube out of the end of a dosing pump when it got clogged like this once.
The Maxijet only pumps that much if it is unrestricted. It is not a pressure-type of pump. The less flow it has, the less efficient it will be. Centrifugal pumps depend a lot on velocity.
The 3.2 GPH has whatever your inlet pressure is behind it. In my case, that is 60psi. The RO membrane and flow restrictor in front of it is limiting the flow, but if you plug the output, it will equalize out to that pressure, or close too it (or as much as the membrane can take, since the waste water output line will still be low). That is why the float-valve kits for RO units are designed to cutoff the inlet water flow when the outlet backs up.
Again, the problem mostly only comes up when something restricts the tube on the output. Unfortunately, it only takes once to do some serious damage, depending on what "gives". By using a "pull" system, versus a "push" system, the vacuum can only result in so much of a pressure gradient, and one that pulls things together versus blowing them apart.
By the way, I am speaking from experience here. I won't give the details:unsure:
-Mike
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Cameron,
Are you SURE your tank pH is that low? Have you measure it with another source? I assum you are taking your pH from your ACIII. What brand probe do you have on it? I found that Pinpoint and Neptune brand probes read WAY different pH than Milwaukee probes. I had a chronic low pH situation on my tank the entire time i was using an old (1yr+) probe. I even claibrated it several times. Each time it read pH below 8. I didn't worry about it too much since my tank was doing great. Recently, I replaced the probe with a new Milwaukee probe and the very same tank with a calibrated probe is reading 8.3 pH.
My only advice is that before you start dosing all sorts of things to raise your pH, make DOUBLY sure that your pH is in fact low.
Are you SURE your tank pH is that low? Have you measure it with another source? I assum you are taking your pH from your ACIII. What brand probe do you have on it? I found that Pinpoint and Neptune brand probes read WAY different pH than Milwaukee probes. I had a chronic low pH situation on my tank the entire time i was using an old (1yr+) probe. I even claibrated it several times. Each time it read pH below 8. I didn't worry about it too much since my tank was doing great. Recently, I replaced the probe with a new Milwaukee probe and the very same tank with a calibrated probe is reading 8.3 pH.
My only advice is that before you start dosing all sorts of things to raise your pH, make DOUBLY sure that your pH is in fact low.
You are correct and I posted the scenario just above where the outlet pressure rises quite commonly... namely when the top off is filled up and hits a valve while the RO unit is still on. If the RO out is unrestricted it's pressure is very low, but there is always a possibility of pushing in my case about 35 PSI through.
I was paranoid on this already... for the reasons you mentioned. I am running one neptune in the sump and one backup reef fanatic in the sump as well. After the low readings, I recalibrated both with very similar numbers. I then ran a pH chemical test and got virtually the same reading. I am pretty sure... about as sure as I can be I am low but I agree it was and is the best corse of action to check these things as best as possible.
