Ph swings

[gcuss]

Hey Guys,

I'm noticing some wild ph swings in my water throughout a 24 hour period. I haven't had this before, so I want to see if it's normal. It's warmed up around here considerably in the last 4 weeks if that makes any difference. 58 degrees to 70. Anyway...

My ph midday is 9, and then in the morning it's down to 8.

My tap water is 7.6 (just re checked it) and Kh and Gh at 120 and 80. Unfortunately I just used the last of my GH KH test stuff, so I can't get a reading from the pond.

I've been changing 10% per day for the last 3 days, and normally I change 5% daily with about a 20 percent change on the weekend.

Sooooo, should I start firing oyster shells in? Hit the panic button and dump a bucket of baking soda in ?? Or can I relax, enjoy my Corona, as this is somewhat of a normal thing??

Thanks,

Grant

[MikeM]

When you tested the tap water did you test direct from the spigot or let the water set for a while first? If the tap water pH is 7.6 after degassing, there are different issues than otherwise.

[farne230]

As you may have read in other threads of mine, I find a .5 swing from morning (low) to evening (high) normal for my pond. I find temp, bio-growth in pond or filter function may cause PH to swing lower or higher. Also frequent water changes, when municipal plants make substantial changes to chemistry may cause a periodic change.
Bob

[gcuss]

Quote: Originally Posted by MikeM When you tested the tap water did you test direct from the spigot or let the water set for a while first? If the tap water pH is 7.6 after degassing, there are different issues than otherwise.

aahh, you see? I should know better than that. No, I didn't aerate first. Will do that in a moment. couple hours with an airstone should do it?

Quote: As you may have read in other threads of mine, I find a .5 swing from morning (low) to evening (high) normal for my pond. I find temp, bio-growth in pond or filter function may cause PH to swing lower or higher. Also frequent water changes, when municipal plants make substantial changes to chemistry may cause a periodic change. Bob

Thanks Mike and Bob I'll get the correct numbers and post that.


Grant

[saratogatan]

when my water source went from deliverinng water with ph of around 7.2 to 8.5, all my koi with beni pigment were done in less than 1 month, now the matsukawa bekko is the top koi in my pond. So, keep an eye on your kohak etc. If I am in your shoes, I would have dump n-teen boxes of baking soda into the pond before I send out the help signal.

stan

[bekko]

Water coming from the tap probably has some excess carbon dioxide (a weak acid) which is driven off during aeration to increase the pH. Either that or you have uncured concrete or something.

pH increases during the day due to photosynthetic activity. Plants/algae remove carbon dioxide driving the pH upward. Over night carbon dioxide increases through pond respiration and atmospheric diffusion and pH declines again.

Oyster shells will have no impact. Baking soda will increase your dawn pH to about 8.6 and will probably increase your afternoon pH to above 9.

You can reduce the fluctuation by reducing the amount of plant life or algae. This may require more water exchange and/or more waste removal. Reducing the overall pH may require an R.O. unit or water softener (unless the jury is still out on water softeners).

Neither the average pH nor the fluctuation will kill the fish although their quality may deteriorate.

-ste

[gcuss]

Thank you to everyone for their responses. Glad I asked, as I was a bit confused by all of it.

I'll figure out a plan that works for me and see if I can get that down a titch.

Grant

[PapaBear]

Steve just nailed my thoughts, and my first question is "what color is your water?" If you've got a green tinge that could well be the main culprit.