Quick PH Question

platytetrafan said:
LOL ok I remember this from chemistry. I am an RN I did test the water but only had API test strips in the house and not sure if it is reliable or not but the KH result was 60 which the bottle says is fine and the GH result was 0 so in plain english what does this mean now since the fish are fine LOL ;).
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Your test strips are not accurate. If you have a KH of 60 (ppm I'm assuming), you have to have some GH. KH is a measure of buffering capacity, the higher it is, the more resistant the water is to changes in pH. GH stands for general hardness and is a measure of certain dissolved ions in the water, mostly calcium and magnesium. A GH of 0 means your water is extremely soft because it has no measurable calcium of magnesium, it would essentially be deionized water which would definitely not have a KH of 60 ppm.
 
12 Volt Man said:
a pH change from 7.0 to 6.0 represents a 10 times decrease in hydronium ion concentration.

a change from 6.0 to 5.9 is a change of:

10^-6.0 - 10^-5.9 = 0.74..times decrease, which is a lot less.

(since H+ concentration is the antilog of the (-pH) = 10^-pH.

I wish I could show exponents on here! :)

remember:

pH is the negative logarithm of the hydronium(H3O+) ion concentration. chemists often shorten this notation to simply H+.

there is also a pOH as well, which is the opposite of the pH scale..

pH chemistry can be quite complex...and it brings back evil memories of my school days..:mad2:
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You're still missing the point. First of all, a pH change from 7.0 to 6.0 represents a 10 fold INCREASE in the hydronium ion concentration, but I think you just made a typo and understand this so we'll move on.
I was cutting some corners in my earlier post for simplicity's sake and do understand what a hydronium ion is, but I still prefer to type H+ (probably because I am a scientist and work with chemicals and pH on a daily basis). But back to my main point, and that is based on the fact that the pH scale is logrithmic. While you are correct that every point represents a ten-fold increase, you are failing to recognize that this also means that these increases build upon each other the further you get from a pH of 7.0. You are trying to equate changes that are truly 1 order of magnitude apart. Look at the actual changes in ion number and you will see that the change from pH 7.0 to 6.0 is far smaller than the change from 6.0 to 5.0. Here is the actual change in number of ions in 1 Liter of water after converting from moles to actual number of ions:
pH 7.0 to pH 6.0 = an increase in H+ ions of 5.418 X 10^17
pH 6.0 to pH 5.0 = an increase in H+ ions of 5.418 X 10^18
pH 7.0 to pH 5.0 = an increase in H+ ions of 5.9598 X 10^18
Obviously, the greatest increase occurs with a change from pH 7.0 to 5.0, but it is only slightly greater than the increase that occurs between pH 6.0 and 5.0. More importantly, notice that the increase in number of ions occurring between pH 6.0 and 5.0 is MUCH greater than the increase that occurs between pH 7.0 and 6.0. When you look at the actual number of ions it becomes clear that a point on the pH scale represents an ever greater change in ion number the further you get from 7.0. Go ahead, do the math yourself!
 
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LOL ok...so I tested the water again and it is registering 6.0 on the nose is weird though the water from the tap tested around 7.6 today most of the time it is 7.0. My other tanks are registering with a ph of 7.0 just my 36g is registering 6.0. The fish are totally fine should I use the ph up to increase the ph? I am not sure what to do. I don't have the liquid drops for gh and kh just the strips.
 
IMHO, a change in pH is never is important as the reason the pH has changed. Two major reasons for a decrease in pH is the kH or other water "ingredients" of the source water changing or the kH being chewed up by biological activities. Compare the kH of your tap water and tank water. If your tank water is lower, then the likely source of your decrease in pH is water changes that are inadequate to replenish the carbonate hardness that is being eaten up (source of base) or conversely, increases in the amount of acids in your tank. I never consider pH a factor but a product of water parameters. If your water has adequate buffering capacity, which at 60 ppm seems reasonable, try larger water changes to alleviate this. Vacuum well to remove sources of decaying material which produce acids.

Water with kH and no gH is possible, usually found when water is treated in some way to remove hardness. Though thats not to say the test strips are accurate either. Most fish appreciate some calcium and magnesium the factors that produce gH.

Hope this helps
 
I am wondering Lfs manager told me to use a coral skeleton when I first got the tank set up to help keep the ph stable do you have to change it every once in a while does it ever lose its effectiveness?
 
Don't use any of that pH up or down. The fish don't really care whether the pH is at 7.0 or 6.0, the difference is not very noticeable to them. Besides, usually after adding that stuff, the tank will just re-establish a pH close to the original one within a day, so all that you accomplish is adding more acid or base to your water you don't really need, throwing away your money, and causing pH fluctuations (which is most likely more stressful to the fish than the pH of the tank to begin with). Besides, if you make a mistake, you can really do some damage. Canuck is right, pH itself is almost never the problem, but often a side effect of some other problem. How often are you doing water changes and what percentage are you doing? Do you have any live plants in the tank? Do you have any driftwood in the tank? Do you test for ammonia and nitrites? What do those tests read? Not that test strips are very reliable, but if they show detectable ammonia or nitrites, that's something to worry about.
 
All parameters are fine nitrite 0 nitrate 40 ammonia 0 ph 6.0 sometimes 6.4. I do water changes about 30% once month tank is a 36g. I have a white coral skeleton in the tank for almost a year now. All the fish seem fine I have platies and rainbows that I was told like a higher ph but I also have tetras too that like the water more acidic see my sig so you see my dilemma. I am inclined to do nothing since the fish are fine very happy swimming eating like hogs. No driftwood no live plants all artificial.
 
36g corner cycled: 4 rainbowfish,4 white clouds,1 danio,4 peppered cories,3platies,4neons,2 algae eaters, 4 serpaes,4 bleeding heart tetras,4painted tetras?

Is this the tank in question? If so you might be overpopulated? 34 Fish in a 36 Gallon?

I have "soft" water in my home and I use Baking Soda to help buffer...
 
So, even if you have the biological filter to process all the fish waste, the end result is that fish metabolism will cause a decrease in pH over time. It appears that you have very soft water, not a ton of buffering capacity, a lot of fish, and you are going quite a while between water changes, so I think that over time, your pH is dropping. If you do more frequent water changes, I think that you'll find that your pH will not change so much. I prefer to do weekly 50% changes in my community tank, but sometimes I get lazy and skip a week. It's probably not necessary to do 50%, but the rainbows especially seem to appreciate the frequent, large changes, and I always see lots of sparring and mating behavior the day after a w/c, so it's worth it to me. In any case, don't try to raise the pH just for the rainbows, they'll do fine at a pH of 6.0, however, IME, changing the water more often will make them happier and keep them healthier. BTW, what kind of rainbows? If they're bosemanis, turquoise, or red (irian) rainbows, they're probably feeling cramped in that small a tank with so many other fish.
 
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