Raising Ph without raising alk?

[Celkat]

Hi all- any suggestions? My calc and magnesium are perfect and my alk is on the high end of the acceptable range so I don't want to raise it. Ph is at 8.0 so want to push that up a bit. Any thoughts?

 

[Dowtish]

Adding more O2 to the room might bump it up. Opening a window for instance, but that is not something you can do at all the time. 8.0 ph is fine btw, why are you wanting to raise it? sometimes chasing a number when all your other parameters are stable is kind of pointless and in some cases do more harm than good.

 

[Murfman]

Adding Co2 will actually drop the pH. Increase the surface agitation on the top of your tank to pull in more O2.

pH Simply Explained
pH (power of Hydrogen) is simply a measurement of the acidity or alkalinity of a solution. A pH of 7 is considered to be "neutral", neither acid or alkaline, while pH above 7 is alkaline or "base", and below 7 is acidic.
The normal trend for pH in a saltwater system is downward, or more acidic, which stems from the addition of acids into the aquarium. These acids come from several sources, the primary ones being: (1) excess carbon dioxide (CO2) from respiration caused by lack of sufficient gas exchange, (2) nitric acid from biological filtration (nitrification), and (3) organic acids from metabolic wastes.
Of course respiration and metabolic wastes are a natural part of the ocean, but the reason that sea water pH does not change is that the water contains a number of chemicals, such as bicarbonate, calcium, carbonate, borate and hydroxide, all of which act as natural "buffers" that reta rd the drop in pH.
So where does alkalinity come into all of this? The degree to which a solution maintains its pH when acid is added is termed the "alkalinity" of the solution. Related terms used in reference to aquariums are carbonate or calcium hardness, and its German equivalent, KH or dKH. The amount of "buffers" in sea water determines the alkalinity.
When the pH in a saltwater system starts to drop, it is an indication that the buffers are getting worn out, and the increase in acidity needs to be corrected. (1)

(1)Aquarium pH Control For Dummies - Saltwater Aquarium pH and Alkalinity Simplified

 

[mojo]

very nice Murfman. Great info .

 

[Dowtish]

Co2 was a typo, meant adding 02

 

[Aquaph8]

Co2 was a typo, meant adding 02

Fixed it.

 

[orthokardia]

+1 on great explanation. I have had great luck using kalk to boast Ph. It does add alk also, but over time a high Ph seems to settle the Alk to the proper balance. As always dose with care, test often, and get smart b4 u start.

-bart

 

[Murfman]

Since my tank sits in the basement and Co2 is heavier than air, I added long intake hoses to my skimmer pumps and put them outside the window to pull in fresh air. Right now my tank sits at 7.8 in the AM and goes up to 8.0/8.1 during the day. I know when it is time to add Kalk to the reactor, based on my tank pH.

 

[beaslbob]

Simple: consume the co2 with macro and other algaes.

 

[LegoZ81]

Simple: consume the co2 with macro and other algaes.

you can help reduce swing by running the light on the macro section opposite to the the tank lighting also.

 

[Celkat]

Thanks so much all for your advice. Great posts and great forums here. Hope everyone had a safe and healthy new year.

 

[CJO]

Co2 was a typo, meant adding 02

Still won't work

Adding oxygen won't raise the pH, but taking out CO2 will. Another option, besides adding macro algae, is to use a CO2 scrubber. Macro algae is an excellent first choice.

CJ