First, the answer to your question. Almost any acid will work. Some are more potent than others, so there are some risks to using the more potent ones, but from your pond's perspective it doesn't matter much. Hydrochloric acid from the hardware store is the cheapest, but it is potent and needs to be handled carefully.

Now the answer to the question you didn't ask. Should you mess with the pH? In my opinion you are probably just as well off to leave it alone, even if it is high. You should check the buffering, AKA alkalinity, or sometimes called kh. It is probably high, but you should check it. If your buffering is between 100 and 400 you should not try to mess with the pH. If it is higher you could think about adding some acid, but watch the buffering closely, and don't pay too much attention to the pH. Usually people get into trouble by only watching the pH. It won't change much as you add acid, then all of a sudden after you have broken the buffer, the pH will crash and kill your fish. Pay attention to the kh!!!

Your best course of action is to leave your ph alone.
Many of us live with off the chart ph with no problems.
Trust me, if you try to bring it down it won't stay down and wide ph swings will do more harm to fish than if you just leave it alone.

I havent messed with it at all. Just getting to the end of getting everything setup. Wanted to check the ph and it was off the charts. Just old habit from my aquarium days and city water.

our water is so hard I have to soak the fuacets in CLR every 3 months. After filling the pond for the first time After about a day you could see the calcium settling to the bottom and covering the liner in a whitish powdery film. Im glad our drinking water goes through the softener.

You can add baking soda. The pH will drop and stabilize at 8.4. Adding citric acid is a very temporary solution. Baking soda should be added slowly over the course of several days, not all at once. It will increase kH. What is your kH?

Baking soda is really the only product that should ever be used to drop the pH slowly and stabilize it. But like others have said, it is usually safer to just leave it alone, if it is stable. What is the pH and kH readings you are getting when you test? Please do NOT add acid....a rapid drop in pH (even a rapid drop with in the safe range) can kill fish.

Bill, you said after a day you checked it, right?

Try this first, wait a few more days, or setup a bucket and aerate it for a day or two.
Then test again.

A lot of times you'll get a high pH right out of the faucet from lack of CO2. Aerating it will drive more CO2 into the water, bringing the pH down.

Our water is like that. It comes out at about 9.4-6 pH. After I aerate it for a couple of days, it's 8.2-3 pH.

I have stock tanks to aerate the water before I use it for water changes. Be glad if it's the same for you, it's buffered pretty good.

I have never heard of using baking soda to bring pH down. I do know it will bring pH up to 8.4 and then stabilize it at that point, but to bring it down is a new one. Can either hoovb or ccoombs1 explain how this works? Usually a buffer reacts with either the H+ or the OH- to prevent pH changes, and I know how the sodium bicarbonate reacts with H+ to make H2O, CO2, and NaCl, but I'm not clear how it would react with OH- to bring pH down.

larryl,

I don't understand it completly myself, but it's some sort of chemical reaction. I know it works because a couple of my friends do this to buffer their pH at a lower point. Here's an explaination I found:

"But how can the bicarbonate act as a buffer to go the other way, lowering the pH if it is too high? In that case the bicarbonate ion would give up its hydrogen as an ion, thus adding acid, lowering pH, and becoming a carbonate
ion (C03). HCO3 = C03 + H bicarbonate carbonate + H acid.

Because of its chemical makeup, Baking Soda has unique capabilities as a Ph balancer or buffer. Buffering is the maintenance of a stable pH balance, or acid-alkali balance. As a buffer, Baking Soda tends to cause acid solutions to become more alkali and to cause alkali solutions to become more acid, bringing both solutions to a stable pH around 8.1 (slightly basic) on the pH scale. A buffer also resists pH change in a solution, in this case maintaining a pH of 8.1." The nature of baking soda is that it will give up H+ ions making more acids,
but only if the pH is above the buffer point. When it does this, it leaves behind carbonate ions, which could precipitate as calcium carbonate, (limestone), of calcium magnesium carbonate, (dolomite), if there is enough
carbonate and it is not being pushed back to bicarbonate. "

Im still waiting on my new wide range test kit to come in. The complexities of water confuse me. I have not tested kH yet. (waiting to test kit) Im glad your guys are here :) I know back from the aquarium days to slowly change pH. Wide change of .2 of more could be deadly to fish.

For now the few feeder comets are doing fine.

Messing with ph up and down is worse for fish and plants than a stable ph no matter how high.

Believe me, even if you try the baking soda to bring the ph down, it won't stay down.It might stabilize for a short period of time but as you add water, etc. the ph will go right back up. I have really hard water too and I've been through this from when I first started ponding and water gardening. Unless you really have the time to stay on top of it, I would just leave it alone.:)

Well, I know you have already gotten a lot of "leave it alone" messages but here is another one. Our water comes out of the tap with Ph off the charts high, low total hardness but a high KH. I tried ONCE to get the water down - even slowly over 5 days - and lost a favorite fishie. I have two three year old koi and 5 goldfish of various sizes and they are just fine in their 8.6 water :)

Stable is key and as hot as it has been down here in southern Louisiana this summer with little rain, I have had to add a lot of water. It is a lot safer (most important) and easier and cheaper (convenient but not necessarily my prime concern) to just treat for chlorine and not have to fiddle with pH at every water addition.

Oh, and I am not saying it is best for you but check how your local water treatment facility chlorinates your water. If it is with chlorine gas, spraying smaller additions of water into a pond (10% of total volume or less) can outgas most of the remaining chlorine and enable you to not have to figure out a way to treat for chlorine at each addition.

How does baking soda work to buffer both up and down? Here is a great link that describes the importance of bicarbonates.

http://www.akca.org/library/empty.htm

Im on a well. Chlorine is not a concern. 8^)

I havent messed with it and all seems well.

Im more ticked that the water has so much disolved lime stone and calcium that every time I get evaporation it leaves a god aweful white ring on everything. Looks terrible until I top it off again. Then it just gets worse when the water level drops again.

wow, great stuff ive been driving myself crazy for 3 days trying to get below 8 and now i see all this, im going home tonite and drinking my pond water instead of a glass of wine or a beer, because ive been so nuts over the ph that i feel like im creating a microbrew! Ill have to get a kh tester and leave it at that. the fish have been in for about 6 days now(3gf) and they seem to be fine but one died the first nite in the water and the petco guy said i should lower the ph before he replaced the fish. God am i stupid, he just wanted me to buy something else before he gave me a freebie. Thanks to all of you people for your insights , i hope i can oneday not only enjoy my pond be be proud o my new knowledge!

I wanted to bring this back.

I have accepted the high pH as it is the way it is and have left it alone.

But now after several weeks in the pond all my plants look aweful. Even after dosing them week after week in MG. I have aaded fertilome liguid iron both by foliar spray and by dosing the water.

I have fert all the potted plants twice.

The lilies have sprouted lot of pads but are only the size of an apple. Several pads have died off.

The pickerel is sending up new shoots but is quickly getting yellow veins.

The water lettuce and hyacith is just about dead.

Primerose creeper which exploded out the gate is starting to die back and turn red.

The only thing doing well is some duckweed.

Pretty classic choloris.

These where all shipped to me 2 months ago maybe its normal but they look terrible. Whats the point of a water garden where your plants are turning to crap..

pH is holding at or above 9.0 test kit doesnt go any highier then 9.0

nitrate and amm or all well below dangerous levels.

I dont get it.

I need to order a iron test kit.

OK, back to basics. What is your kh?

Your ph likely isn't the problem with your plants.

kH is off the chart on my tesk kit. I dont remember how high it goes.

ph is causing clorosis im pretty sure. Its classic signs.
I just ned a solution to fix the nutrient deffciency? without overloading on iron.

Buyorsell great reply can to add some help insight???? what is then if its not the off the charts ph?

Normally, I would agree that messing with pH is not warranted, but if your kh is as high as you say it is, I think I would experiment with a little hydrochloric acid. I would CHECK THE KH EVERY DAY and add some diluted hydrochloric acid daily until the kh got below 350. I wouldn't even bother checking the pH until the kh got down to 350. If your kh is as high as you say, this process could take many days. You don't want to go overboard and add too much acid, just sneak up on it. Again, CHECK THE KH EVERY DAY. You don't want to break the buffer, you just want to bring it down to a reasonable level.

By leaving some buffering you will still have a pH over eight, but hopefully you won't have calcium carbonate constantly precipitating out. I'm not sure this is really the root of your plant problems, but as long as you check the kh every day, I'm sure this won't hurt anything.

Remember hydrochloric acid is very potent, so handle it very carefully. Start slowly, and, seriously, check your kh every day.

As an extra precaution I would double check my kh test kit before I started. Dilute one part of your pond water with ten parts of bottled spring water, or distilled water. Check this with your kh test. This should give you a reading that is about one-tenth of your pond kh. Hopefully it will be in the lower middle of your kh test kit's range. If this is not the case, you should question the reliability of your test kit. You might also want to test your spring water straight. It should be near zero.

I get chlorosis on my water hyacinths and pickeral and our water here is very soft and acidic. No mineral deposits ever on the plumbing or anything else.

Many ponders grow beautiful plants in areas with high ph/alkalinity.

Is your pond in full sun?

What did you pot the plants in? soil? gravel?

How much Miracle Gro did you dose them with and which formula?

Does your pond have algae?

During the months of July- through late August, my plants look bad because of the hot direct sun- high air temps and high water temps. As the air and water temps cool in early fall, my plants have a last spurt of looking good and blooming until our first freeze.

I used to think something in my water was causing it but have noticed the same pattern for 3 years now.

I always find discussions of alkalinity and pH interesting. Larryl is on target about the comments regarding adjusting pH. I was somewhat surprised that the solution that Billinpa had picked up for adjusting the pH down was mostly citric acid. Citric acid, and also vinegar (acetic acid), are weak acids (meaning they dont release the hydrogen ion too easily) but more importantly they are organic acids which will probably be broken down in your pond quite rapidly. I would expect to have them essentially gone within a few hours to a day or two at the most....which would put you just about back at square one. Inorganic acids such as hydrochloric or even sulfuric will not be broken down by the bacteria in you pond and as such are better choice IF you decide you ABSOLUTELY MUST lower your pH. Comments that they will kill your fish are partially true...if you dump a bunch in and are not careful to sufficiently dilute it and mix it in the pond. Hydrochloric acid, as discussed by Larryl would be my choice IF you really need an acid; it goes under the name of "muriatic acid" in your local hardware store. However, as stated by Larryl and others, I suspect you may not really need to adjust your pH. IÂve seen ponds having a pH as high as 9.0-9.3 with no apparent ill effects on their plants or fish, although there clearly are some varieties which will not do well at those levels.

The concept of adding sodium bicarbonate to drop the pH is an interesting one. Theoretically the bicarbonate ion, HCO3-, can release a hydrogen ion to be converted to the carbonate ion as stated above. However, this reaction is part of the carbonic acid weak acid system and does not happen very effectively unless the pH is higher than about 9.5 or so. At a pH of 10.3 your alkalinity will be half bicarbonate and half carbonate ions with a small amount of it (approximately 10 mg/L) in the form of hydroxide ion. But at a pH of 9.5 only about 15-16% of your alkalinity is in the carbonate form plus thereÂs very little OH- around at that point to help "force" the hydrogen ion off the bicarbonate ion to have it act as an acid. The advantage of adding baking soda is that you wonÂt have to worry about adding too much since the pH will not be driven below 8.3-8.4. But the amount of baking soda you would have to add may contribute to other problems namely the overall salinity - sort of the sum of all the cations and anions in the water - which can be detrimental to some plants if too high. Billinpa, you indicated that your water is extremely hard... I suspect that your salinity level may also be quite high which might have been a significant factor on the water plants you added to your pond. You can also help your plants by adding a small amount of chelated iron (approx ½ tablespoon per 1000 gallons) as well as potassium nitrate (about the same dosage). This will supply the iron in a form the plants can use as well as nitrates and potash at levels not harmful to fish but which would help green up your plants.

If anyone is interested I would be happy to go through the equations and calculations regarding the relationships for alkalinity and pH and discuss it in much more depth or I can provide you with a list of some excellent reference texts on aquatic chemistry if you prefer. Please feel free to drop me an e-mail if youÂd rather  any way I can be of any help.
ÂDavid

Ok I goofed ont he kH

kH is 100 ppm.
Hardness is off the chart.
nitrate 0
nitrite 0
ammo 0
pH at or above 9.0

Water temp is holding right at 80.

Yes pond is in full sun. But the area where the water lettuce is, is shaded by surrounding plants.

All plants are planted in a mix of pea gravel and larger (3/4 inch) river rock.

Algae wasnt an issue until about 2-3 weeks ago. Since, I have had a major algae bloom. Im pretty sure I over fertilized in an effort to help the plants.

Miracle grow was used at 1 Tbs per gallon of pond water. 4 Gallon in a large tub. That has been the only thing that has ssemed to help. I have to do it every week to keep the plants green. Oly use Mg on the floaters. The lilies and pickeral are OK but not good. The lilies have shot about 6-8 pads each. (not expecting a bloom, planted lat, early July) But they are small and dont last long. They come up reddish, turn green for about a week and then start to turn yellow and dry up. Pickeral is doing the best but is still quite yellow, although it is beginning to bloom.

I have added iron little at a time over the past week and half. Im waiting on my iron test kit to be shippied. I dont want to OD.

Possible potassium deff???

Im at a loss.

Thanks Prof, I figured that this subject was right up your alley.
It was time to get you out of retirement [from the forum] and have you post one of your long winded,but really, really interesting posts. LOL
Take care old bean,
"Horton"

I dont have to worry about salt. I dont add any.

Salinity isn't about adding salt although adding salt (or sodium bicarbonate for that matter) will increase the salinity. It is just a general measure of all the ions in the water, not just salt. You can add calcium sulfate or magnesium chloride or potassium chloride...all will result in an increase in salinity.

As a follow-up to adding Miracle Grow - I dont use it in the pond since it also adds a fair amount of phosphorous. By adding potassium nitrate (aka, Stump Remover in many farm and gardening stores) you add potash and nitrogen without adding the phosphorous and therefore (hopefully!) encouraging your vascular plants to out-compete the algae for the phosphorous.

Hope this helps.
David

Thats good to know about salinity.

Ok but here poses a question. Water hardness is the amount of calcium and magnesium in the water. How do you decrease these? you brought up in an earlier post about adding baking soda might cause to much salinity. And the end result being bad fot the fish and plants. Im assuming this could be the issue I am having since my hardness reads off the charts.

I didnt add miracle grow to the pond I used it as a bath in a tub to soak the plants in for a few days. It very much greened them up and prompted lots of new growth.

Im wishing for city water now. I didnt have any of these issues before.

Im going to stop on the way home and look at the bottles of stump remover.

Maybe add a few teaspoons and see how they respond in a few days. Im have givin up on the beautiful pond full of plants until next year but I hope to get this figured out before winter. I can atleast be ready for next spring.

Thanks David and all the others for the help.

I would repot the waterlilies into dirt, clay garden dirt. They don't do well in gravel/rocks unless the pond is well established and has loads of nutrients for them to use. Even so, they always do better in dirt than rocks. Cheap plastic oil pans make great pots for waterlilies.

I have also found pickeral to be the same way. I grow a lot of plants in mesh pots in gravel but it doesn't thrive like many others.

Billinpa, there are several ways to reduce the hardness but frankly I wouldn't worry about it. As to reducing the overall salinity? About the only way to do that is to collect rainwater in a barrel and add it to the pond. However, I'm not terribly happy about doing that for several reasons: a.) the rain water has essentially no alkalinity and usually has a pH of around 5.5 or so (it can be more acid than that or even somewhat higher pH). So adding it to your pond you've got to watch your alkalinity closely. b.) rain water running off your roof (or where ever you collect it from) will usually carry a lot of "junk" with it...bird poop for example. This can add a great deal of decaying organic material, microbes and phosphates to your pond that you don't need in there. Adding the occasional cup or two of baking soda isn't going to change things drastically on the salinity front... you'd have to be at very high levels. What does your health department report on your water (assuming that's who runs the analyses for home wells in your area) say regarding total dissolved solids (TDS)? If it's much over 1000-5000 mg/L you might have to be a bit careful.

Sorry I misunderstood about the Miracle Grow. The dose you indicated (1 tablespoon per gallon) is rather high for a soaking your plants. If I recall correctly that's the dose that MG recommends for sprinkling around on the plants and surrounding soil in a garden about once every 2-3 weeks but not for plants in a pot or a soak. You'll find that the Stump Remover is a white powder, usually in a plastic bottle. Use it sparingly as I mentioned above and try to avoid breathing the dust. I find one bottle will last 1-2 years. As mentioned above...I've also tried growing my water lilies in artificial media but they didn't do nearly as well as having them in soil in a pot. I use a sandy loam with very little organic matter in it and add 5-7 lily fertilizer tabs to each pot. You may wonder about the phosphorous added this way...the pot is plastic, no holes in them with the fertilizer tabs at the very bottom. That way any nutrients diffusing up through the soil must pass by the root zone and don't make it into the water.

Whatever you do, relax, enjoy your pond and have fun learning all the information!
---David
P.S. Horton? Me? Long winded? Ha! Just my old age and senility or is that salinity?

I'm a big fan of adding nitrates, but in your case I don't think the plant problem are caused by a lack of nitrates. Nitrates are normally produced at a constant rate by your fish, so the floating plants are never really without nitrates. The addition of nitrates is helpful to stimulate the consumption of phosphates by increasing the growth of plants, but plants in a pond will usually not show any signs of distress just because there isn't an abundant supply of nitrates. I don't think it will hurt to add nitrates since you have tested a zero nitrate level, but I doubt it will help with the plant problems you describe.

I just went back and reread your descriptions of the condition of your plants. I get that they are not doing well and the hyacinths are nearly dead and that you think it sounds like classic chlorosis. And you are wondering if it is a potash deficiency. I think you might have posted more detail on another thread but I'm too lazy to go looking for it, so some more detailed description of the water hyacinths would be helpful. Color? Growth, if any? Roots? Veining on the leaves?

If adding iron didn't help I think you can forget about an iron deficiency. Iron deficient hyacinths usually turn around in a couple of days when you give them iron.

Potash deficiency? Hyacinths don't die of a potash deficiency. They turn a funny sort of olive drab color, stop growing above the water level, and develop huge root systems, but they don't die. It won't hurt to add potash, but if the above description doesn't sound like your plants, don't expect a miracle.

If your kh is 100, you definitely do not want to add acid. Adding baking soda seems like a good idea since the kh is a little on the low side of a comfortable margin of error. It's not a crisis, but I like to see it higher than that. With the moderate kh and high hardness you might have just the right setup to try adding baking soda to reduce the pH , as others have suggested.

I wouldn't be concerned about putting in too much iron. You have to have a long term level of over 5 PPM to risk damage to your fish. Do the math and shoot for 1 PPM, which should give you a pretty large safety margin. One PPM is quite sufficient to provide all the iron your plants need for a couple of weeks anyway.

If you are concerned about the sodium level being too high, you should test it and see.

If you want good help you have to give good data. This thread got way off track on your previous assurance that the kh was off the chart, when it was really 100. I'm not saying this to chide you, but that sent this thread into a lot of territory that wasn't really helpful to you.

You are corect larryl. Its my bad memory to blame. The kH was alittle on the moderate to low side but the gH hardness was off my test chart.

I finally found an iron test kit at a local aquarium store. Tested the water. Zip, zero, zilch. None. I added an over priced aquarium chelated iron product. ( I have to find fertilome and have some shipped) At $12 per 16.5 oz was a little over priced. Added tested added tested. Got the level to check this .1mg/l Every bit of literature I have seen graduates at ppm except the test kit I have. great. Well I read the manual with the kit and it recommended from .1 to .25. I figured it recommended for aquariums so I went to the low side. Ill give them a few days and see whats happens.

Water hyacinths:

They looked great when I rcvd them. Put them in the skippy and shaded for the first few days. Started to yellow between the veins. The end of the leaves and bulbs then turned brown and started to rot. They did send out a few daughter plants but not many. Never really grew any at all from the original size. The roots where tanish about 3-4 inches long and feathery. They turned black and became very soft. After the first MG bath the remaining leaves turned back to green, sprouted lots of new growth, and new roots appeared. The roots are now white and about 3-4 inches long. I would not consider them overly long for the plant size at all.

Pickerel: Each plant has sent up 4-5 new leaves. All of which are much smaller then others I have seen. Maybe only 3-4 inches top to bottom. They emerge green but quickly show yellowing between the veins. 1 plant has bloomed but only a blossom the size on a dime. Very tiny. I did pull one of these out of the pond for a look. The roots have outgrow the pot already and trail about a foot out of the bottom hole in the pot.

The pickerel and lilies are getting a 2 tabs every 3-4 weeks of 12-18-8 plant tabs(that maynot be exact but close)

I wish I could just sit back on enjoy the pond, but eveytime I sit pond side I wonder "whats going on here". Lack of vigerous growth. fish seem happy and content. Growing readily and love to eat. They are just goldies until I get everything settled. I only feed them once every 2-3 days but they look fat and happy eating the insects and algae.

Thanks again guys for all your help I really do thank you.

It sure sounds like chlorosis to me. Keep testing the iron. Any amount of iron that the test kit can detect is enough to keep the plants healthy. The chelation sometimes makes the test a little slow to measure the iron, so give it a little extra time before you read the result.

the test kit I have test for both free iron (bad) and chelated iron (good). The test for chelated takes 30 min to register.

I have been adding handfulls of ironite to the water in the falls over the past week. My first iron test still showed zero on both tests.

Maybe David can answer this but is there a direct connection between iron levels and hardness and/or salinity (meaning above post about calcium and magnesium)? Just some FYI. Im curious if/how hard water depletes dissolved iron in some form of chemical reaction.
Or am I just terribly unlucky and have zero iron in my well water.

Im not sure about the TDS in the well. the test was performed before we moved in and I never got the result other then the builder had to install a UV light before we could get an occupancy permit. I guess for extra precaution he dumped several gallon of bleach down the well too (rolling my eyes). It smelled like pool water for about 2 weeks. I finally opened all the faucets and let them run for several hours to flush it all out.

Hardness is defined as all divalent and trivalent cations. Usually calcium and magnesium account for 99+% of your total hardness. Since iron can exist in either the divalent or trivalent state it contributes to hardness but nothing of any significance - you can't detect the change with the typical hardness kit. Calcium/magnesium levels in your water won't impact the iron solubility to any great extent. Iron is effectively insoluble for pH's between 4.5 and around 9ish which is why you want to use the chelated form to help your plants. This is also the reason that if you add a non-chelated form of iron you will see a bit of your alkalinity drop since it reacts with the alkalinity through a series of reactions to form iron hydroxide which is essentially insoluble in the pH ranges I've indicated. Iron or any added cation or anion will increase salinity but given that the concentrations are usually very low compared to other ions it is not significant. Not sure why you're having trouble getting liquid iron (chelated form) ...just about any hardware or gardening center carries it around here. Sometimes - depending on whose product you get - there may be a bit of copper in it but usually this is of no consequence at the normal iron doses you should be adding. I've put a link to a "quickie" Excel spreadsheet for calculating doses for adding iron below if it's of any help or interest. By the way, be very, very glad you don't have any iron in your well water!! If you had it you wouldn't believe the taste and other problems.

It is very common upon completion of drilling a well for the driller to dump 2-5 gallons down the well to sanitize it. The fact that you now have a UV light system suggests that you may still have something going on. Hopefully he got the liner grouted in place nice and tight.
---David

David you are my hero...... J/K

great spread sheet.

Just wanted to report my iron is holding at .25 mg/l ??? I dont know why my test uses this scale.

My plants greened up over night. And both my pickerel have bloomed over night. Lilies have turn back to green, water lettuce and hyacinth have turned back to green. All without their weekly bath in MG. Its almost magical what a little iron can do. Although I had to use 16.5 oz of 1.0% solution to register on my test kit.

Ah, the beauty of the metric system. As it turns out.25mg/l just happens to be .25PPM. We avoirdupois folks have to use PPM because ounces per gallon is just too ridiculous. Here is a tip for you when calculating anything that has to do with ratios of stuff to add to the pond. It is way easier to convert to metric for the calculation and then convert back when you are done, than it is to try to do the calculations in avoirdupois. Turn your quarts into liters and the calculation is far easier. One quart equals one liter---close enough for pond calculations. When you are done 26 grams is one ounce, but if you use 25, you can do these in your head.

So my iron level is a little high. I should have used half the bottle. LOL

From everything I have read that level shouldnt cause any harm to the fish. The test kit and iron product both said it was safe up to 1 mg/l or 10ppm. Ideal level of .25 to .50 The plants should use it up over time.