PH and Sodium Bicarbonate

[UP ALL NIGHT!!]

I found this when I was researching PH
What do you think?
Common myths about koi keeping "Roark"
Baking Soda Will Drive My pH Up To Over 9.5
Nope. Actually, it will peg it at a rock-solid 8.4. You can completely saturate a water sample with baking soda and never see a pH higher than 8.4. Baking soda is a strong buffer, and very useful as a water additive in carbonate-poor areas. In a properly buffered pond, the dreaded pH "crash" is an impossibility. Maintain your carbonate hardness (KH) in the 100 to 120 ppm range and you can forget about "crashes". Besides being universally available, safe to handle, non-toxic to children, baking soda is harmless to fish at any reasonable level (ie, < 500 ppm).
This interesting artifact is highly useful in testing the performance of your pH test kit. Make yourself a cheap and very reliable pH 8.4 reference solution by dissolving four teaspoons of baking soda in a cup of distilled water. The resulting 8.4 pH solution will show you how much (if any) your test kit has wandered.

I did "test" my PH tests (ECO PH meter and AP drops.)
My meter is off by .4 on the high side? The drops were off by a whole color using the above method it would adjust the measurement by .4 to a PH of 8.2.
My PH has always been high

Any Ideas?
Any Ideas?

[PapaBear]

The Roarkster luvs to play "Mythbuster", and he is right about B.S. and ph. The same is true of any ph buffering agent. The function of a buffer is not to raise or lower ph indiscriminately, but rather to buffer it to a specific level. In the case of baking soda, 8.4 is the target.

[UP ALL NIGHT!!]

Here we go, Does this have something to do with those who regard TA over PH?

I calibrated my new PH probe and it read 8.38 PH In the above solution.

PH is actually 8.6 rather than 9.0? Due to the inaccurate results of my two other tests. This reading is much more comfortable to me. L

[KoiCop]

In point of fact, it's not quite as simple as lots of BS = pH of 8.4

Take for example the pond of our member Steve Joneli (Birdman). His pond swung from over 9 in the AM to over 10 in the PM -- no matter how much muriatic acid and/or BS he added. See his thread (especially post #99):

I Need Help Please

His problems were complicated by a green water (algae) problem.

His solution included not just BS, but also calcium chloride and epsom salts (magnesium chloride) -- as well as knocking down the algae problem with PP and UV.

Seems nothing in this hobby is as simple as we'd like it to be.

[jnorth]

I'm with Don. You can add all the baking soda to my pond you want and never get it down to 8.4.....ever.

[PapaBear]

A pond is not a jug of water, with or without BS...
The buffering solution in the jug still has to deal with whatever is in the pond trying to take things in a completely different direction. BS, or what ever other product anyone may use, still has to deal with the fact that in the pond there is competition for dominance.
Example A, freshly built concrete pond. Not fully acid washed and sealed. Source water ph 7.0, pond water ph 24 hrs after filling 11.5 due to leaching lime from the concrete. A 400 ppm BS solution would drive the ph down toward 8.4, but the lime is still there trying to drive it up again so you never get to 8.4 until the lime is leached out and the concrete is aged. Doing it this way is gonna take a LONG time...
Example B. Green water pond with ph swings from 7.5 at daybreak to 9.5 about 1 hr before sunset. The same 400 ppm BS dosage would probably bring the 2 point swing down to a more tolerable 1 point drift of 8.0 - 9.0, but you still aren't stable at 8.4 or anywhere else.
Bottom line is no silver bullet. BS is a great bandaid in an emergency with predictable results, but if the pond has a problem then the problem still has to be fixed to make things right.

But BS is still a great way to test your ph tester

[rockman]

So speaking of mythbusters, what is the optimal pH reading? I though 7.4 was optimal, but instead should it be 8.4 to 9?

Lately my ph has been creeping up a towards 8, and I was wondering how high would be a concern.

[PapaBear]

I'm not the ultimate water expert, but mid 7's is a very happy place for most Koi. Truth be told they can tolerate water from 6.5-9.0 so long as it is stable and buffered against crashes. Stability is far more important than a specific number to me.
Most of the ph problems faced by ponders revolve around water changes, plants, algae, and kh depletion. Knowing your source water and utilizing appropriate water change schedules is usually sufficient to keep things in order, but every pond has to be managed on its own merits and what you have to work with.
A lot of the work Roark has done playing with water has revolved around his friendship with Roddy Conrad who has many ponds and a TERRIBLE water source. Very expensive water with virtually zero kh value. He has to supplement kh constantly just to keep his filters functioning and reclaim his old water for re-use by nuking the organics with PP in holding tanks. You can count the number of people that approach makes sense for on the fingers of one hand, but it works well for an old chemist who likes to keep Koi and play with water.

[bekko]

The trouble with baking soda is that it reacts too fast. Add baking soda and your pH will change immediately. In my opinion, calcium carbonate from oyster shell or coral rubble is a much better buffer. It reacts more slowly and will stabilize at a lower pH.

Larry is right on about the combined effect of baking soda and other buffers already present in your water. Baking soda will not help if you are trying to lower you pH. All it can do is immediately raise your pH.

For many high-end koi keepers, a KH of 100 to 120 ppm is too high to develop good beni and they shoot at something like 50 ppm. But, at 50 ppm you must monitor the situation most closely because you are operating closer to the edge of alkalinity depletion.

-stevehopkin

[saratogatan]

BS is too expensive too. I use Plaster de Paris, cheap compared to BS. I mix PdP with water the same way construction worker mix them, dry them in to bricks of 2-5 lbs. I will drop one of those into the pond and the usually last 2-3 months. My pond is 6200G, filter 1400G.

stan