Water Quality

[AnthonyRibis]

I recently purchased a KH and GH because I remember someone telling me to get one and it didn't come with my Master test kit. Can someone tell me what range my KH should be at? Should I test for GH?

We have had a lot of rain lately, my pond plants are still dormant except for some plant I grabbed while at the stream fly fishing (They are greening up and have grown). String algae is going strong...

My Readings are as follows, let me know if something is out of wack...
pH - 9
KH - 393.8 PPM
Ammonia - 0
Phospate - 0
Nittie - 0

I know my pH is high and I am not sure if the heavy rain lately has caused this. I did a water change a few weeks ago because it was high and it knocked it down to like 6

My pond is around 9x9x3 deep and I only have 4 small koi.

 

[Waterbug]

Those numbers are fine imo. I assume Nittie is Nitrite.

Rain in your area is normally about 4.5 pH and can be much lower for thunderstorms, like 2.5. So rain could cause pH to drop in some ponds but not yours because you have a high (but fine) KH number. Acid reacts with KH so your pond pH would stay about the same but KH would fall some. When KH gets low then rain can change pH.

Knocking your pH down from 9 to 6 is a good way to kill fish. Especially in the spring because they're already stressed. However I would wonder about the tests. I don't know how big a water change you did, or what your source water is but something isn't adding up. Your pond has high (but fine) KH and I have to assume you didn't add something to raise KH so that means your source water has high KH. Well 6 pH and high KH just don't jive. Makes me think some test result is messed up. But just for kicks say you did a water change that had 0 KH and a ton of CO2 so the pH was really low. For a 9 pH pond with 400 ppm KH how low a pH would the source water have to be to knock down it down to 6? Really low, 2? Way under 6 that's for sure. That doesn't seem possible.

There are ways to reduce pH in a controlled way and keep it down. For example GH can cause the pH to go to 8.4 pH and be very stable. That's about the only use I know of for testing GH. The question is why do you want pH to be lower than 9? Because someone told you or you read it some place? Yet this info source didn't tell you how that is fish safe?

There's 2 ways to keep a pond. Do a few things and then learn why the fish are belly up. Or the reverse order.

What I mean is before you start trying to change pH you should consider learning the basics of pH.

- Stable pH is good. pH swings are bad.

- High KH (above say 200 ppm) keeps pH stable. If you test KH and keep it up you never really have to test pH.

- There is optimal and there is what everyone has. Fish can certainly live in 9 pH water. Tons of ponds are in that area. Yes, it isn't optimal. Are you raising Koi for shows? Even in that world there is great debate on what level of pH, KH and everything else is "optimal".

- If your source water is high KH you'd have a tough row to hoe to get a pond at 7.5 pH. Doing it with acid isn't really a very good idea. Most people use a reverse osmosis system. Expensive. And the results are debatable imo.

It can really be that simple. If your source water is high KH and you have a normal Water Garden fish load you probably never even have to measure KH. Couple of times a year if you like just to make sure. Accept the 9 pH like most people do and you're good to go.

Ammonia is good to test imo, at least until you get used to how your pond works. But for a normal type Water Garden fish load ammonia is never an issue. If you do read some ammonia don't start fixing stuff. Learn first.

 

[AnthonyRibis]

Waterbug, Yes Nittie was Nitrite, typo. Thanks for the great information. I read on a website I believe that a good target pH was 7, that's why I made the water change because I though 9 was too high...

So what would be my target for KH?

Yes I am still learning...

 

[Waterbug]

Places selling products to adjust pH say 7.5 is optimal. People who raise Koi say 7 to 9 is optimal. But lots of ponds are about 9 although test kits start to get flaky out there. Lot's of people I consider good Koi keepers stay in the 8.5 range. In 20+ years of reading pond forums I can't remember anyone ever having pH so high fish died outright. Maybe it stresses them, but it doesn't seem to be a problem.

There used to be a lot, and I mean a lot, of people saying concrete/cement raised pH to 14 and would kill fish but these people knew nothing about everything. Lucky we don't have to deal with that myth too much these days, just a bunch of other ones.

Stable pH is way more important imo and I think it's safe to say that is a very common belief.

Target KH...that can be very simple or very complex. There are people who say high KH does negatively affects the quality of the white on Koi, or maybe it's the red, or both. I assume you're not worried about such things but you may run into those discussions in your research. So lets take that off the table.

The other thing about KH is it can be lowered to keep pH in a more optimal range. That's a little tricky because there's more than just KH to consider when doing this type of thing. But those people are keeping KH down in the say 40-70 ppm range. They have to stay on top of the testing and adjusting to keep pH stable.

Then there's everyone else. We don't like to test water a lot, we don't like to have to adjust stuff a lot and we're not taking our fish to Koi shows. For us KH can't really be too high. A good number in this camp is like 200 ppm. What this means though is there's not a lot of reason to raise the KH above 200 ppm. So like someone with source water that's say 50 ppm they have to add something to get KH higher and they just stop at something like 200 ppm or whatever they like. But if you have source water that's say 400 ppm that's OK too, no reason to fight it down to 200 ppm.

The last issue probably also doesn't apply to you but some people with high fish loads (lots of big fish in a small pond) have to run serious bio filters to convert ammonia. These bacteria also consume O2 and KH. The amount can be surprisingly. Some some of these people keep KH around 500 ppm.

I once read an article about how they thought (in theory) 10,000 ppm was about the max fish could handle but even that was because of the salt level, not exactly the KH being a problem.

So to me there is no realistic too high a KH.

The issue is when you get down in the say 50 ppm range you really have very little buffering and pH can crash.

Based on your KH numbers it sounds like you'd never have a KH issue.