Dear Troy,

I try not to mess with the PH levels. I just make sure the water has enough buffering capacity. You can use test strips bought at the pet store to test this which is called the KH level. If your source water is high in calcium carbonate then you can add some tap water (with dechlor) to increase the buffer. If not then people add different things such as plaster of paris or oyster shells, ect.

Regards,
Lisa

Here is a link that might be useful: Thread on Buffers

Although its better to be too high then too low. Add some baking soda. Little at a time. It wil raise the pH and the kH but the pH will not go above 8.4. It will also increase the buffers to stabilze your pH.

Rainstorms typically play havoc with PH, driving it down in a hurry. I have added baking soda to the water in advance of a big storm but I am more comfortable with Plaster of Paris.
The POP is cast into molds and put in the water once it has hardened. As the water becomes more acidic, there is a chemical reaction with the POP that neutralizes the acid. Once the PH is stable at a slightly elevated PH (alkaline) the reaction stops until the water becomes acidic again.
This is a lot easier than trying to guess how much rain is mixing with the pond water, but it is slower than baking soda (BiCarb).
I put in several molded POP figures(bubbles, fish, starfish) to speed up the process. It never seems so fast it bothers the fish.
If you make POP molds, remember to check the label for no additives. DAP from the hardware store has no additives and is inexpensive. Sandy

You want baking soda, sodium bicarbonate, to buffer the water to prevent sudden drops in the pH and you want something with calcium like plaster of paris (or even some limestone) to provide a source of calcium for the plants and fish. The easiest is plaster of paris (POP). Pour into styrofoam cups, add water, stir until evenly mixed, let it harden and peel off the styrofoam. Toss into pond where you can see it. Once it has become fairly small, replace with a new one. The bicarbonate you add periodically. Test kits do not cost much.

Troy,
I once phoned a popular pool product suppliers regarding what's in their chemicals because the base agent is, as you indicated, used by ponders to raise and lower your points. However, when I discussed it with the company's agent they said that they could have other elements, in trace amounts, not listed on the packaging. That's the problem I guess.

Here where I am in middle america we have high pH out of the tap and very low KH. I too have learned not to mess to much with the pH because swinging it around simply can do more harm than good, not to mention become an endless task. When I did want to lower the pH though I found Acid Magic at the hardware store seemed to be a sensitive acid to use. I would handle it carefully.

The maker, Certol, claims it is equal concentration to muriatic acid but unlike ordinary muriatic acid, they claim it won't burn and can be handled without gloves and has 90% less fumes.

Like others have suggested I've used baking soda to raise KH and buffer.

Bicarb is great for an emergency. It disolves really fast. The POP is slower but is steady which is better for the fish and doesn't require a lot of testing.
Speaking of testing, I don't care much for the strips. they are almost always wrong. I have never had an accurate reading and it is just throwing money away, IMO. A decent testing kit is accurate and provides far more tests than the strips. Sandy

I am currently using manufactured buffers for stabilize the Ph in my pond which is proving to be expensive. What is DAP plaster? Is this a brand or a particular make?

A few comments: if you decide to make the plaster-of-paris pills or tablets be sure that you are buying POP that is made with calcium carbonate. Some versions of POP are made from silicates, won't dissolve worth a hoot and will have no impact on your buffering, pH and little on your calcium concentrations. How to know? A. Check the ingredients if listed. B. Use a small vial of vinegar and place a drop or two on a little bit of the POP...if it fizzes then it has carbonates in it. The DAP stands for the company that makes the POP and is not some weird acronym for it's contents. Sodium bicarbonate is used by many to adjust pH and more importantly, alkalinity, commonly referred to as KH. The strips used for testing, as Sandy has mentioned, tend to be inaccurate and have a bigger problem in that their shelf-life is rather limited compared to the liquid test kits. I've benchmarked both against the gold-standard titrimetric method in a lab and found the liquid ones to be more accurate. The primary advantage of sodium bicarbonate is that it is one of those chemicals that relatively benign in terms of potential problems of putting in too much....once your water pH is at 8.3-8.4 whether you dump in a cup or 10 cups will have no further impact on pH although it will increase the alkalinity. This is NOT true for pH PLUS from swimming pool stores. This product is typically sodium carbonate, not sodium bicarbonate. As you add this stuff and happen to over dose you WILL raise your pH. In fact, it is possible to raise the pH as high as 11 by adding just sodium carbonate...you can use it but be careful. Same goes for using muriatic acid...it can be diluted and used as need be but I think you would be far better off leaving the pH at a stable level rather than trying to chase it around. You will probably find that your pH will vary significantly during the day...low in the morning, higher in the afternoon...just due to the influence of algae in your pond. Bring the algae under better control, plus keep your alkalinity levels above 80 mg/L and you'll have less fluctuation in your pH. You'll probably find that many folks...here in this forum or elsewhere...routinely keep their ponds in the pH range of 8.3 - 8.8 with no major effects on fish, plants, tadpoles, birds, etc. Not true if you're trying to grow fish that enjoy a more acid pH (some African types, if I recall correctly) or plants that are very pH sensitive...I believe there are some native orchid species that may fall into this category, for example.
I used to make the POP tabs but kept running into more frequent problems of locating manufacturers whose products which contained carbonate-versions. Now all I do is throw in a handful or two of sodium bicarbonate (baking soda) once in awhile. Specially add it in the late fall headed into cold weather when things begin to freeze ... want everything well buffered at that point.
Hope all this stuff helps.
---David