pH through the roof!!!

[schenko]

My husband has an outdoor pond (100 gal) that has been established for maybe 2 months. The pH keeps rising to as much as 9.0, but our tap water is 6.0. The pond gets part sun/part shade with a biofilter and a small waterfall.
He has one lilly plant with only 6-7 leaves and 1 shubunkin (6"), 1 red fantail (4"), and 1 little goldfish (maybe 3"). What is he doing wrong??? He did a water change yesterday and brought the pH down, but today it's back up to 8.5. He keeps finding frog eggs in the pond, but he siphons them out as soon as he finds them.
The ammonia, nitrates, and salt levels are fine. CAN ANYONE HELP???? Thanks!

[Kasakato]

The rain? Next time it rains, get a sample and test that.

[Kasakato]

"I've been reading some of your posts & thought maybe you'd have an answer for me.

My problem is kH, pH, and gH. My tap water is 6.0pH, <1kH, <1gH . The fish I picked, thrive in a range of pH 5.5 - 6.8; gH 3-8; kH 4-5. My pH is great from jumpstreet, but the rest is way off.
I added buffer up & tank hard (ingredients list says only calcium & magnesium) & raised my levels to 6kH and 5gH, but it raised my pH to 7.6.

The way I understand it is:
Crushed coral - raises the kH but not the gH? what about pH?
Calcium carbonate - raises both kH & gH with pH??? (where do I buy this?)
baking soda - raises kH & pH but not gH
magnesium - raises gH but not pH?
Epsom salts & calium chloride do what???

With the crushed coral - how does it know when to stop increasing kH? If I increase the kH with crushed coral, how do I raise the gH without raising the pH??? Or do I put the buffer up and Tank hard in the water like I've been doing & do Co2 injections???

If I leave the water alone - the gH & kH will go down to 1. And the pH will drop to 6.5 - which is great. Do I adjust or do I leave it all alone & go with what my tap gives me??? I'm so confused...

Also, everyone says not to have more than 1 or a pair of dwarf gouramis, and no gold algae eater. So I have to change my list - again. So I chose this set up:
4 Apistogramma cichlids
4 Penguin fish
2 German Blue Ram
1 Dwarf Gourami
3 Dwarf Suckermouth catfish
3 Cherry Barbs (starter fish already have)

Do you think this is a good setup for the water I have (or am trying to achieve)? I thank you so much for your help!!! I can't wait to get this thing going!
Thanks again - Schenko!"

This isent my best area so take a look at: http://www.aquariacentral.com/forums/showthread.php?t=53321&highlight=Crushed+coral from post #4 and on

[Watcher74]

Raising the Gh will not affect your Ph. It is calcium and magnesium. And those are needed if you have any plants in the tank/pond. I believe Flourish has a product for adding this to your water.

Kh and Ph are related. Coral does not "know" when to stop raising Ph. But if you do regular partial water changes, it will stabilize out within a few weeks.

Usually the Ph it is a measure of how much carbonates and bicarbonates is in the water. But if you combine those Alkaline elements with Acidic elements(such as driftwood for example), you can lower your Ph without changing the Kh. I mean, the acidity of the driftwood isn't going to remove the carbonates...just counteract their affect on the Ph.

Add Arm&Hammer baking soda for Kh. Get the Flourish stuff for Gh.

And research all the different things that you can use in the tank to counteract the baking soda's affect on the Ph. (driftwood, certain types of substrate, etc.)

Then you just have to "play with it" to get both the Kh and Ph where you want them.

[Watcher74]

Schenko,

You need to find any factor that would cause a rise in Ph. Test the tap water and pond water for Ph AND Kh.

See if the Kh is rising with the Ph. If so Carbonates and Bicarbonates are being introduced in the pond somehow.

Things that would raise the Ph that way would be:

Leaching from the soil that has them, rocks that have them, something being added to the pond water that has a undesired side affect, the food maybe?

Check all that out and get back to us.

[schenko]

Well, I guess it could be the rocks he has in there. He has some river rock and some "slate-like" flat stones set up to be shelving and such in the pond. Not a whole lot of rain here lately - been REAL dry... Probably not a rainwater problem. If I had to guess - the rocks. Thanks for your help! I will tell him & see what we get after we take them out! :)

[Watcher74]

Slate should be ok. The "river rocks", well who knows. What is the foundation of the pond?

Plastic, some type of concrete, dirt, etc?

[RTR]

If you had a lot of submerged plants in the pond, I'd bet on the plants. That can be easily tested by running AM and mid-late afternoon pH tests. High pH during max photosynthesis reflects total stripping of the water of CO2, and if Val is present in quantity, biogenic decalcification on top of that.

If it is stable high pH round the clock, bet on substrate or rocks.

[Watcher74]

originally by RTR
if Val is present in quantity, biogenic decalcification on top of that.

I'm not sure if I understand that one. Do you mean that Vals use up a lot of calcium or something?

[RTR]

Vals are among the plant that can extract carbon from carbonates. When they do this the local pH goes way up. If lots of Val is present, the whole tank pH rises sharply. The reaction produces hydroxide ion (OH-), strongly basic. Calcium precipitates out on the plant's leaves so that they feel like coarse sandpaper.

For more detail, see:

http://stage1.aquatic-gardeners.org/Plants/CO2/decalcification.html

[Kissofthegorami]

In my experience, plants raise PH. But not up to 9.0. Thats high. Goldfish like higher PH and I dnt know if its going to be a problem. Why destroy the frog eggs? Its probbaly illegal to do that anyways. Either keep the tadpoles and raise them in your pond (will eat algae) or put the eggs in a nearby pond/lake.

[TORTUGA]

I have a similar problem. My pH is 9 tested in the morning. The goldfish and most of the plants are doing well. I'm on a well and my water is a 9 also. I'm looking for a natural way to bring it down - if possible. My other question is should I leave it alone since things seem to be going ok.
Thanks!

[RTR]

Kiss...Plants can raise the pH above 9. Just because you have not experienced it does mean it does not occur. Did you do any reading on biogenic decalcification?

Tortuga - what is the KH of your water from the well?

[Kissofthegorami]

Kiss...Plants can raise the pH above 9. Just because you have not experienced it does mean it does not occur. Did you do any reading on biogenic decalcification?

Tortuga - what is the KH of your water from the well?

lol no. Better things to do. I said IN MY EXPERIENCE.

[boroughmal]

Any cement or lime present on the rocks as mortar will also send the p.h,through the roof. It leaches into the water. Only remedy, Remove them.
Lower pond p.h with peat moss in cotton sacks.Naturally.