KH, pH, and don't assume everything's ducky

[Telkwa]

Hey, good morning to all!

My wife and I have been dinking with ponds for several years, but always terribly amateurish until a coupla years ago when we started over, with a lot of help from this forum. We're now just partly amateurish.

A couple of our goldfish have a grayish look to them which we assume is a thick slime coat. If that is what we think it is, then that's an indication that's something's not right.

So, we have a basic test kit. It's about a year old so not yet time to pitch it and get another. pH is a bit high this season at about 8. We tested in the morning and in the evening. Very little change. That should be an indication of good KH, from what I've read on the internets. We didn't know because we didn't have a KH kit. Got one this morning. API brand, just KH, supposedly fresh stock. Two drops and it went from blue to yellow. We couldn't believe it. Tried it again. Same results. According to the directions, 0 to 3 drops is

 

[addy1]

Always good to test the pond and the source. Our well is very soft. Our pond has finally gotten a little harder.

 

[sissy]

I have 2 big filters in my basement that filter all the water that comes out of the well .I did not want any nasty stuff in my water that i drink .Every time it rains hard the water test is different .I just added outside hydrants that do not go through my filter system .I figured plants and grass don't care if water is filtered or not .The pond gets filtered water .I even took the old standard filter they put on wells and added it onto the hose and put a charcoal filter in the filter tank .I found the connections my son cut off to get it off the water line are the same size as a hose .So I just unscrewed the old cut off ones and put the hose on the in side and a smaller hose on the out side of the adapters .I now added that new water works hose to it since it is drinking water safe .I bought another one of them also but was wondering how they would hold up against the summer sun hitting them .The best thing is 3 lb weight for each 50 foot hose and so far not one kink and even ran over the hose with my lawn mower for got it was there .I did not have the blade going but had a whole cart load of mulch I was hauling and it did not hurt the hose .I guess if I ruin it it has a warranty and i'm covered so why not put it through a real test .

 

[Telkwa]

addy, what method did you use to harden the pond water?

 

[addy1]

addy, what method did you use to harden the pond water?

I added around 100 lbs of crushed oyster shells, put them in my bog where the water flows over them constantly. This was at the beginning of last year, since then the alkalinity has been in the 100 range. I have not tested the well recently, I just recall it was real low i.e. soft and very acidic

Here are other ways to harden the water:

Raise alkalinity by adding Calcium Carbonate, concrete blocks, oyster shells, limestone, or even egg shells. To raise the alkalinity by 40 ppm, add 1/2 oz of Calcium Carbonate (precipitate powder) per 100 gallons of water. A bag of oyster shells or even a concrete block or two (not cinder block) submerged in the pond or filter area may be all that is needed. Keep a close eye on the pH while adjusting Alkalinity levels.

 

[Telkwa]

Patti found a 2lb. box of baking soda (raises KH, but also pH) in the pantry, and I bought some sodium bicarbonate (lowers pH and total alkalinity) at the one & only pool shop in this area. Not a high percentage of pool owners in rainy Western Washington...

So these two ingredients fight each other to some extent. We did some rough calculations, then added some of both. I think that we probably didn't add nearly enuf of either, but better safe than sorry. Will check again in the morning and go from there. Just for comparison with folks in other parts of the country, our pond temp finally snuck above 50 deg. F today.

 

[Telkwa]

It's important to note that baking soda has a pH of about 8. So, yes, it'll raise pH some, but not right thru the roof. We decided late this afternoon that we hadn't put enough baking soda in to make much difference, so we mixed up almost a pound and slowly poured it into the pond directly over the froth caused by that hyperactive Hakko HK40L air pump. Within a few minutes some of the fish (including the one with the thickest slime coat) were swimming in place just a few feet from the upwash created by the bubbler. I've been reading today about osmo-regulation, and how proper hardness makes for a much healthier environment. Is it possible that the fish could have detected the harder water that quickly and been attracted to what they perceived as the source??

BTW, I thought this post was very helpful. Maybe it's because I'd read enuf about it and some of the terminology was finally starting to click? Anyway, maybe it'll help someone else who's trying to get their arms around this subject.

 

[Waterbug]

Baking soda can raise pH above 9 if GH is low.

Measuring KH is important, more important than pH imo. Adding carbonate (baking soda, oyster shells, etc.) will stabilize pH and that's way better than pH crashes. Without any buffering pH can swing back and forth from 4.5 to 12 depending on conditions.

But if you want to take one more step...
Just adding carbonate can cause pH to climb above 9, which isn't the end of the world as long as you keep 0 ammonia and continue to keep KH up. But a more optimal pH would be lower and that can be done with GH, measures magnesium and calcium. At good GH levels, like 150-250 ppm, the excess carbonate ions will precipitate out of the water and keep pH at 8.3. As pH drops below 8.3 the precipitated carbonate ions will dissolve back into the water and raise pH right back to 8.3.

GH can be raised by adding a pound of calcium chloride flake (from hardware store for deicing, 77% calcium chloride, or swimming pool supply) per 1000 gals. And a pound of Epsom salt per 1000 gals to add magnesium.

Carbonate sources...
It's true that oyster shells, egg shells, human bones, etc, can all add carbonate. Lots of people like these things (except human bone) rather than baking soda. I guess they sound more natural. There is a downside that should be considered. None of those "natural" materials provide carbonate very quickly. You could you still have low KH, and/or a heavy rain could use up all available KH quickly and crash pH. The "natural" materials will eventually bring KH back, but you'd still be looking at pH swings.

Concrete is a really poor carbonate source as pH has to be very low to get any carbonate. This is why concrete lasts for decades and decades in water without dissolving.

 

[Telkwa]

Waterbug, thanks for the input. This never ends, does it? Now I gotta go buy a GH kit, too?

Just took samples a few minutes ago. 5 drops of KH reagent to get to yellow, so after letting everything circulate overnite we're almost back to the miserable '3 drops to yellow' result when we first tested a day earlier. 6 drops should be right around 100 mg/L, as you know, and the test kit sez 11 drops would be in the 200 mg/L range, so we've got a ways to go. Although I want to fix this right now we don't want to stress the fish.

What would you suggest? Would you continue with baking soda until KH was better, then start GH testing? Or would you be addressing GH at the same time? Does calcium chloride or Epsom salts fight with the baking soda (KH)? Or do they both push the pond in the right direction if you're low on both KH & GH?

I don't know if I sound like a nut, but this morning some of the fish are continuing to swim in the outwash from the bubbler, like salmon headed upstream. They've been lollygagging aimlessly all spring. To think that they detected the harder water from the baking soda mix I poured into the bubbler froth yesterday seems like quite a leap, but they are acting differently today...

We get roughly 47" of rain in Western Washington. I feel like an idiot for never addressing what that can do to a 3' deep pond. Next winter we'll be testing regularly.

 

[Telkwa]

Hmm, wouldn't let me edit...
Went back into town, picked up a GH kit, green by the 3rd drop. That's roughly 54 ppm. Looks like I've got more work to do...

When I was picking up the test kit, I chatted with their pond guy. One thing led to another, and he asked me if any of our fish had cloudy eyes. Well, yeah, at least one but I thought it was 'cause he was old. The pond guy thinks I should salt the pond, something we've never done. Can anyone give me some generic directions? I know I've gotta re-measure the pond dimensions to make sure of volume, then I'm under the impression that water softener rock salt is a good alternative to those small/expensive containers of "pond salt".

 

[Waterbug]

Patti found a 2lb. box of baking soda (raises KH, but also pH) in the pantry, and I bought some sodium bicarbonate (lowers pH and total alkalinity) at the one & only pool shop in this area. Not a high percentage of pool owners in rainy Western Washington...

So these two ingredients fight each other to some extent. We did some rough calculations, then added some of both.

I'm a bit confused...baking soda is sodium bicarbonate.

What would you suggest? Would you continue with baking soda until KH was better, then start GH testing? Or would you be addressing GH at the same time? Does calcium chloride or Epsom salts fight with the baking soda (KH)? Or do they both push the pond in the right direction if you're low on both KH & GH?

I don't like to suggest a course of action...I know nothing about your pond and can't unless I'm on site doing the tests myself. I can answer questions as best I can which you can research on your own to make up your own mind.

47" of rain which for western Washington is about 4.5 pH (can be as low as 3.6 pH) would use up a lot of KH. So I think it's good you're looking into how this all works.

I do think if a person was going to test and adjust GH that sooner would be better than later. I assume you already know the danger of raising pH if there is ammonia present...but then your water temp is pretty low and that makes ammonia less toxic.

Baking soda can push pH above 9. GH stops it from going above 8.3. Most ponds have good GH just from their source water, so adding baking soda doesn't raise pH above 8.3. Also, in most water gardens can handle a pH of 10 and even above. Depends on the fish load and size of fish. As chemistry moves away from optimal it's the bigger fish that generally have the biggest problems because of their larger metabolism. I ran ponds at 10 pH for years with no problems, but I had a light fish load.

So GH buffers the water from going above 8.3 and KH buffers it from going below 8.3. Without the GH pH can jump around above 8.3, but that's not as bad by a long shot as low KH and pH jumping around between 4 and 12.

I don't know if I sound like a nut, but this morning some of the fish are continuing to swim in the outwash from the bubbler, like salmon headed upstream. They've been lollygagging aimlessly all spring. To think that they detected the harder water from the baking soda mix I poured into the bubbler froth yesterday seems like quite a leap, but they are acting differently today...

Impossible to tell. The baking soda is releasing CO2 into the water as it is reacting with acid. Once KH stays stable the high CO2 will level off. So it's possible the fish are after more O2. Most of the time they can handle this, but if you're concerned you can increase water movement which dumps the CO2 faster.

 

[Waterbug]

When I was picking up the test kit, I chatted with their pond guy. One thing led to another, and he asked me if any of our fish had cloudy eyes. Well, yeah, at least one but I thought it was 'cause he was old. The pond guy thinks I should salt the pond, something we've never done. Can anyone give me some generic directions? I know I've gotta re-measure the pond dimensions to make sure of volume, then I'm under the impression that water softener rock salt is a good alternative to those small/expensive containers of "pond salt".

I have a low opinion of "pond guys". I also have a low opinion of people who hear some random symptom and say "add salt". Cloudy eyes? Add salt. Lethargic? Add salt. Too active? Add salt.

I will say adding salt, if done at correct doses, isn't a big danger. But it does cause the fish to produce slime. That energy could be used to fight other, maybe real dangers. I don't add stuff unless I'm pretty darn sure I know what I'm curing.

And there are some medicines that can't be used with high salt levels. So if next week the fish have other symptoms and maybe those meds are needed you're kind of screwed.

If you really want to treat with salt I think it should be done in a small tank where you have some control. Oh no, my math was off and I added too much salt! No problem in a tank...big problem in a pond.

 

[Telkwa]

waterbug, I appreciate your input. Let me go back thru the last couple of posts.

Isn't baking soda a common treatment for low KH? I thought I understood something out of the last coupla days' research. We apparently have low KH, which I thought could be countered with plain old Arm & Hammer baking soda.

And now it looks like low GH, too. I just got back from town again. Mixed some Epsom salt in a bucket and poured that in. Couldn't find any calcium chloride at Home Depot. They've put all their winter stuff away.

They did have solar salt. I've only added a little. Considering you're not a big fan of salting, perhaps I shouldn't ask this, but how do you get coarse solar salt to dissolve? I went at it with a drill motor and a paint mixer for a few minutes but the salt crystals won. If I can find a way to dissolve it, I'm thinkin' about purchasing a pen-style salinity meter and shooting for a relatively low concentration of salt. Then again, after reading your last post, maybe it'd be better to isolate the fish with the cloudy eyes and treat it in a small tank...

We tested for ammonia yesterday. Zero.

 

[Waterbug]

Isn't baking soda a common treatment for low KH? I thought I understood something out of the last coupla days' research. We apparently have low KH, which I thought could be countered with plain old Arm & Hammer baking soda.

Yes

And now it looks like low GH, too. I just got back from town again. Mixed some Epsom salt in a bucket and poured that in. Couldn't find any calcium chloride at Home Depot. They've put all their winter stuff away.

Pool supply stores have calcium chloride.

They did have solar salt. I've only added a little.

Adding a little...thinking it would help a little? Not really the way salt works.

Considering you're not a big fan of salting...

I'm a big fan of salt...when needed, and properly dosed. I'm not a fan of adding stuff just for the heck of it.

...how do you get coarse solar salt to dissolve?

I put it into panty hose and set it in stream or falls. Few hours to a day to dissolve.

better to isolate the fish with the cloudy eyes and treat it in a small tank...

Please at least keep in mind that because of your water temps your fish immune systems are just starting up, the fish may recover on it's own. I've read many threads like this over the years and many don't end pretty. I was happy to add my 2 cents on KH, GH but I'd rather not read any further. Sorry.

 

[Telkwa]

OK, Waterbug, thanks for the help. I'm not seriously considering isolating any of the fish and playing doctor. Just thinking out loud.