pH

buzz

buzz

Active Member
I have a fairly new saltwater tank. All levels are now perfect, except pH. It is a bit low. Not much, but not perfect either. I saw on a site that the addition of diluted baking soda will bring the pH to 8.2. I hesitate in adding baking soda to my tank. Is this a good practice? Or is there a better way?
 
nicenakago

nicenakago

Member
Buzz happens to be my friend that I have recently converted to the salt side.... Just wanted to bust his chops (I'm not that big of a jerk to people I don't know) :rolleyes:
 
worm

worm

Member
doesn't using baking soda help bring your pH DOWN? there are many forms of ph buffers on the market, and yes Searchems is a good brand (i use it with no trouble). to be honest tho, i don't add those types of chemicals directly to my reef. i always make sure the new water i am making has the correct pH before doing a water change.
and if your pH is changing between regular water changes, you are doing too much or not enough of something. maybe the sharks or other experiences aquarist can help you better...
IMO
good luck!
 
saltyrich

saltyrich

Active Member
If you're shooting for a reef tank, you definately want the ph a little higher than 7.9. I think that most of us on this board keep it between 8.1 and 8.3 (based on what I've seen posted). It appears as if this is the safe zone for most inverts and corals. Fish are more tolerant of lower ph's.
 
lutefisk

lutefisk

New Member
Your pH will swing with the photosynthesis and other factors in your tank. Your pH will fall when the lights are off and rise when the lights are on. Some people use a refugium that is lit when the main tank is dark and dark when the main tank is lit to minimize this swing.
Ultimately, if you bring your alkalinity up to the 3.5 - 4.0 meq/l and Ca up to 350-450 ppm your pH will fall into an acceptable range. If your alkalinity is too low your pH will drop because of increasing H+ ions.
The alkalinity and Ca levels should be chemically balanced with respect to each other. Here is a nice calculator to make that job easier.
Andy Hopkiss Calcium and Alkalinity Calculator
Baking soda and washing soda are perfectly good additives (just be sure to get the straight stuff - without perfume etc.) Most comercial additive are use them as their main ingredients. Many people mix the baking soda with washing soda in a 6:1 ratio. This "homebrew" is really about as good as the expensive store "bought powders". As with any of these powders be sure to mix them with DI water before slowly adding to your tank. I add my by dripping. Washing soda will cause a higher rise in pH than baking soda.
A key strategy is to shoot for your target alkalinity and Ca levels rather than a target pH. If you get the alk and Ca right the pH will fall into line.
The pH range of 7.7 - 8.4 are considered normal in most reef tanks. People running CO2 reactors will run towards the low and of this range and people dosing kalk will be towards the higher end.
As SaltyRich mentioned, be sure to do this slowly - sometimes over days.
Once you get your alk and Ca levels up I highly recommend using kalkwasser for your evaporation make up. It will add alk and Ca in balanced proportions.
Two part additives are also good - but expensive and like Kent Super Buffer and other additives will eventually result in a proportion of sodium ions far higher than natural saltwater.
Kalkwasser and CO2/Ca reactors do not have this drawback.
Good luck!
Paul
 
olsenjb

olsenjb

Member
Just to answer worm. baking soda is a base...meaning it would push the pH to a higher number. 7 is neutral pH. Anything below 7 is considered acidic...the lower the number to more acidic. Anything above 7 is considered basic...the higher the number to more basic. So, adding a base such as baking soda with raise the pH. Hope this helps. :)
 
lutefisk

lutefisk

New Member
Boy, I sure wish that this BBS allowed the author of a post to edit it. Please excuse the multitude of grammer errors in my previous post. Teach me to type in a hurry :rolleyes:
olsenjb - Yes, vinegar and baking soda foam when they are mixed. But, the pH altering affect of baking soda is actually pretty low when compared to other additives. I understand that it will actually lower the pH (an acidic affect). Washing soda and kalk will definately raise an aquarium's pH.
BTW - another thing to consider is if your water is fully oxygenated. If CO2 levels are too high your pH will be too low. That is why it is so critical to have good water movement at air-water interfaces. Skimmers also help.
Something that blew me away is that some people have raised their tank pH 0.2 by just opening the windows of their houses. What was happening is that in our wonderful, energy efficient, new homes, is that not enough air exchange takes place and the CO2 to O2 levels increase - thus also affecting our reefs.
But, I suspect that Buzz's problem stems from too little alkalinity.
Here is a great article on pH
Additionally, measuring pH with color charts is practically unusable. So is the most expensive pH meter if you don't calibrate it properly.
So - when it comes to pH, if you are on a budget, get some resonable quality Salifert, Hach, or Lamotte Alkalinity and Ca test kits and skip the pH. If you have a few bucks, pick up something like the Pinpoint meter and the one-use sealed packets of calbration fluid.
Paul
 
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