Chasing pH - larger CaRx?

[ca1ore]

I think most experienced reefers will generally counsel to not chase pH - often the ‘cure’ is more problematic than the ‘disease’. My system runs low pH. Lower in the summer (down to 7.7 at night) than in the winter, which is curious to me because the house is equally sealed up (anyone have any clever explanation for that). Spring and fall are higher because the windows are open. Although I never add buffers or pH adjusting chemicals, I do and have explored other ways to indirectly raise it. I tried running fresh air to my skimmer. Made no difference. That my well circulated system marinates in a high CO2 environment clearly swamps any benefits the fresh air might provide. Likewise the use of a CO2 scrubber - simply extra cost in media without any commensurate benefit. I do run a blower into my basement fish room that, on temperate days in the summer or winter, helps a bit. I also run a calcium reactor which clearly does not help.

Recently I got this ‘brilliant’ idea that if I built a much larger reactor, with double the media, I’d be able to run it at a higher pH and still get the necessary minerals to the tank. That would, in turn, mean slightly higher pH levels. With my old reactor, using reborn media, I had to run it at an internal pH of about 6.7 to get enough melt. With my now installed bigger unit, I am more like 7.0 to maintain desired numbers (9.3; 450; 1350). It’s only been a few weeks, but I am seeing about a 0.2 improvement in average pH. 7.9 versus 7.7 as a nighttime low; 8.1 versus 7.9 as a daytime high. Haven’t hit 8.1 in years. Maybe it will make no difference, ultimately, to the health of the tank; thus reinforcing the thesis that chasing pH is pointless. Makes me feel better though. Will be interesting to see if what I have observed over these few weeks is sustainable.

To be continued ....

 

[biecacka]

Ever think of using kalk?
I have low ph too and am thinking of using kalk in addition to my CaRx. Not sure though...


Corey

 

[ca1ore]

Ah, yes, forgot to mention that ..... been using kalk in the make up water forever. That might actually explain why my ph is lower in the summer than the winter. Evaporation rates are slower in the summer thus less pH 12 water being added.

 

[biecacka]

Yes. That makes sense. Do you use a reactor or in you ATO


Corey

 

[ca1ore]

I went through a series of DIY reactors, none of which really worked all that well (mostly the circulation pump kept clogging up). Then I tried the two little fishes one, that was a fail too (water ‘wand’ thingee also clogs up). Finally I got the avast one .... success. For kalk, a stir bar is the best and most reliable approach.

 

[biecacka]

Yes. I have looked at that one too.

Corey

 

[Auto-pilot]

Hey your ph problem is probably caused by high carbon dioxide. Carbon dioxide forms carbonic acid in water that brings the ph down. If you have your ph and your alkalinity you can directly calculate your carbon dioxide concentration. Using the same formula of you have the alkalinity and carbon dioxide you can calculate your ph
Do you have plants in your tank, maybe they would raise your ph by absorbing the carbon dioxide

 

[Auto-pilot]

Ok re-reading your post I have a question for you! What is the benefit to having a reactor vs just dousing into the system? Sounds like reactors can create problems where dosing doesn't

 

[Randy Holmes-Farley Verified Community Expert]

I think most experienced reefers will generally counsel to not chase pH -often the ‘cure’ is more problematic than the ‘disease’.

That is only true if you take inappropriate actions. Appropriate actions will never cause harm.

 

[Randy Holmes-Farley Verified Community Expert]

Ok re-reading your post I have a question for you! What is the benefit to having a reactor vs just dousing into the system? Sounds like reactors can create problems where dosing doesn't

All dosing methods have pros and cons. None are perfect in every way, and what is best for a given system may vary depending on many factors, such as the goals of the system, the hobbyists access to money, the indoor air quality, etc.

 

[Randy Holmes-Farley Verified Community Expert]

Recently I got this ‘brilliant’ idea that if I built a much larger reactor, with double the media, I’d be able to run it at a higher pH and still get the necessary minerals to the tank. That would, in turn, mean slightly higher pH levels. With my old reactor, using reborn media, I had to run it at an internal pH of about 6.7 to get enough melt. With my now installed bigger unit, I am more like 7.0 to maintain desired numbers (9.3; 450; 1350). It’s only been a few weeks, but I am seeing about a 0.2 improvement in average pH. 7.9 versus 7.7 as a nighttime low; 8.1 versus 7.9 as a daytime high. Haven’t hit 8.1 in years. Maybe it will make no difference, ultimately, to the health of the tank; thus reinforcing the thesis that chasing pH is pointless. Makes me feel better though. Will be interesting to see if what I have observed over these few weeks is sustainable.
..

It's hard to say that in general a bigger reactor will "always" raise the pH, because in the extreme, I think it will lower it again. There is a likely a happy medium.

The reasoning is this:

You need to add a certain amount of CO2 to the reactor to drive the pH down to the point where ANY CaCO3 begins dissolving. That initial CO2 is "wasted", but still ends up lowering the aquarium pH. Imagine a reactor bigger than the aquarium. You'd need to add a massive amount of CO2 to bring all that water down to the point where the media begins to dissolve. Then all that water, at, say, pH 7.4, enters the aquarium, driving down the pH.

 

[ca1ore]

Hey your ph problem is probably caused by high carbon dioxide.

Not probably ..... definitely. Not a lot to be done about it though, particularly when it’s hot outside and the AC is running. It may well be that a larger CaRx will make no difference in the long run. I’ll know for sure by the end of the Summer.

 

[Wiskey]

I have always had the same problem. I like to run alk around 7-8 and I love CA reactors. Kalk is not easy to manage because it can powder over optical top off sensors, and the residue can jam mechanical top off sensors. Eventually, I bought an Avast Pressure based level sensor which I connected to my Apex and it is immune to Kalk. I also have an optical high-level sensor (if kalk is dosed when the water is that high then I have more serious problems) and I have a mechanical Low-level sensor. The Kalk fowling compounds seem to float, and I've never had a kalk problem with this sensor.

Right now I'm trying something new with the DOS pumps, but I like to use Kalk topoff to keep my PH levels higher and reduce stress on my CA reactor or dosing. I've modified the Avast Kalk mixer to make things fairly hands-off, and with the addition of their level sensor I've been happy with the solution, plus my PH has ranged from 7.9 to 8.2 in the last day even with my low(ish) alk. I also have a high CO2 house, if I were to remove Kalk I'd never hit 8.

Whiskey