Pond Boss Forums GENERAL QUESTIONS Water chemistry Low pH, low Alkalinity in Fresh ponds/Lakes

With the wet spring this year and a few times in the past, We've had a few panicked calls about new ponds with low pH(5.0-5.5) and low Alkalinity(near 0). Its important to let a new pond sit for at least a few weeks after you get torrential downpours to allow your pH and alkalinity to adjust before jumping the gun and calling the lime truck. Rainwater is around 5.3 pH and 0 Alkalinity. I've had up to 30 acre lakes have 5.3 pH a week after filling up to 60-70% full. Then a month or so later its 7.5, 50 alkalinity and had a decent bloom. I would recommend waiting at least a month on a new lake after any big rain before testing the water, it'll help keep your wallet full and your sanity intact.

That is one reason that is good to have the soil tested (in addition to a water test). Water will reflect the soil over time. For example, if the soil test indicated the need to add 2 tons of lime per acre and your water test (after a rain) indicated add 4 tons per acre, then you are safe adding 2 tons as per the soil test.

Holy pH Batman!!

I took a water sample after a 2" gully washer that flowed a bunch of runoff into my very stable pond. It has always been ~ 6.5-6.7pH.



pH was below 5.0. Alkalinity came out as 0 - It was pink before any reactant was applied - aka 0ppm.



Scared the crap outa me as I just stocked 2 days prior. I thought maybe that Crescent Pond seep thru the spoil bank that flowed into this pond really wrecked it. Just about panicked - went and got 500# of aglime (All they on-hand at the time, Thank God) and put in the steam flowing into the pond - called in an order for 2T more...of AgLime and came here to PondBoss saw the post above between the order and delivery - read the above. CNX the order.

Retested a couple weeks later....


Thanks emactxag!!

I have a similar question. I have a 1/3 acre (when full) water table pond here in southern Delaware. The climate here is similar to Maryland or Virginia. The pond was dug this past fall during a drought and has now filled up and is about 4’ deep. With the spring rains, it will likely top out at 5’ deep.

With an aerator on, I tested the water ph and got a reading of 4.5. That pond is murky and muddy looking and has no established plant life yet except the contractor mix that stabilized the banks this fall. The pond is also in the middle of a loblolly pine forest and mainly gets its water from the groundwater table plus a small amount of runoff from the banks. The area around the pond is clear so a ton of pine needles don’t fall into the pond. The surround soil layers are about 6” of topsoil, 4’’ of loamy sand, then grayish blue and white silty clay as you dig further down.

Frogs, turtles, and insect like creatures love the drainage ditch next to my pond. I assume those same creatures will like my pond too.

What about plants? I ordered a wetland Maryland coastal plains seeds mix for the banks. (Lots of fox sedge)

What about fish? Will ph 4.5 be ok for minnow, sunfish, bass, pickerel, yellow perch?

Should we consider adding Ag Liming to the pond and surrounding soil? (I want to have small amount of hybrid striped bass but I assume the ph is way too low.

Should I just let nature do it’s thing and keep watching the ph?

Please direct me to the correct forum if I’m in the wrong place.

Lankyfish, welcome to the forum. You have to watch alkalinity also and not just pH. Being in a pine forest, I'd expect the alkalinity to be low. Get the soil pH tested. Your pond will end up like the soil pH if no ag lime is added. You want the water alkalinity to be at least 40 to give you some wiggle room. Check the pH of the drainage ditch water.

As for plants, you might have some plants show up. Sago Pond weed, Bushy Pondweed etc. might show up by themselves. Do a search around you to see if you can find some place that sells underwater plants. You don't want aquarium plants because many of those will be too fast growing for the pond and just cause problems. American Pondweed, eelgrass, Sago Pond weed, basically any of the potamogeton genus are good for a pond in moderation.

With the pond only being a max of 5' deep, that will cause some issues managing the weeds since sunlight can get to the whole bottom of the pond.

As for fish, what are the fishery goals for the pond?

Essup,

I am considering a few possible fishery routes for the pond.

Idea #1 - Not chase the ph with ag lime, and let the pond stay acidic and see if some acid tolerant fish will thrive. So far, I think my bull minnows, fathead minnows, and mosquito fish have been ok. There is a place near me that sells pumpkin seed sunfish specifically for water bodies that have low ph. Then, I’d like to have a small amount of larger predators. I would start with LMB, but if they don’t thrive, I would then try our local chain pickerel. (I wish our northern snakehead were legal because they’d probably thrive).

Idea #2 - Not chase the ph with ag lime, and let the pond be acidic and add some yellow perch as well as my collection of minnows. Our local fish farm breeds yellow perch and our local YP supposedly do well in acidic conditions. I wouldn’t worry about the YP getting stunted as long as they were healthy. They would just replace the usual bluegill.

Idea #3 - Ag lime the pond regularly. If I get a suitable neutral ph, I’d love to have minnow, bluegill, and a small number of hybrid striped bass. If the hybrid striped bass can’t survive the hot summer, then add a few big large mouth bass.

Idea #4 - Minnow and hybrid bluegill for more size. Then add just a few bass incase any wild bluegill sneak in and spawn. Can those hybrid bluegill handle low ph or do they need the ph closer to neutral?

The problem with low pH is that plants and algae can't utilize nutrients in the water. So, the food base will be more limited than if the pH was 40-50+. As to what fish are able to thrive in low pH waters, I honestly don't know. Our alkalinity here is naturally in the 150+ range.

But with Pumpkinseeds, Bluefill or Hybrid Bluegill you will need some sort of fish predator that has the mouth gape to handle fish up to 1 year old. Dr. Dave Willis in the Dakotas found that Smallmouth Bass alone cannot control Pumpkinseed numbers.

Essup, thank you for the info and low PH and nutrient usage by plants. I’ll consider that.

Does anyone have experience with a pine forest pond being left natural, without altering the chemistry?

Here in Delaware, all of our farm ponds (not forest ponds) will thrive naturally without intervention. (Maybe some overgrowth of algae or plants if not managed or aerated).

If I want my dream pond of a few HSB, I’ll have to lime my pond for sure. But it would be cool if Mother Nature was able to regulate the pond just enough to let acidic tolerant fish thrive.

For your current low pH consider starting with YP and JUST one LM bass. Add about 100 YP any size into your 0.3 ac. If you are an angler consider adding just one hybrid striped bass or one SM bass, or just one channel catfish or just one bowfin, or just one snakehead with the one LMbass. Single individuals of two or three different of each predator specie should control the YP numbers. IMO for your situation and your goals you do not want predators reproducing making lots of new predators that overpower the forage fish community Pond Boss had a very good article by Dr. Neal about benefits of snakehead. I will look for the issue that had this article. See post later below.

Bill Cody,

That is an awesome plan! I really like the idea of a mix of just a few predators and a bunch of forage fish.

Do you know if anyone on Pond Boss knows if the YP and just a few predators (or any other acid tolderant fish) will do ok in a pine forest pond PH of 4.5? (there are no pine trees within 50' of the banks) Do I have to Ag Lime the pond no matter what?

Bow Fin would be cool! Didn't think about that.

Perch will tolerate a pH of 4.5. At a pH of 3.5 reproduction is reduced. Acid tolerance was not merely the result of an overall hardiness, but reflects specific adaptation to low pH. Lethal acidity was near pH 3.2. It was reported that both YOY and adults survived longer than 10 d at pH 3.05 in 19 C water.

My 1/3 acre pond is a water table pond. I also need to consider the best way to stabilize the banks when the water level drops in the summer/fall.

With a current ph of 4.5, would it be best to add ag lime or not in terms of possible plant growth along the 8’ shallow shelf?

One helpful option IMO would be contact a couple local concrete contractors to see if they would bring you waste concrete from projects they know about. Contractors are always looking for ways to dispose of waste concrete. Have them dump it in separate piles along your banks. Then when the water is low, arrange the concrete pieces along the shorelines. These will stabilize the shoreline, provide habitat for minnows, invertebrates, crayfish, and probably add some calcium hardness to the water.

It would be helpful to do a soil test of the sediment shoreline. This would give some insight to what native plants would grow along the shoreline to form stability. Examining / identifying the native marginal plants along local water bodies would give you an idea what plants that are likely to grow in your pond's soil conditions. I am not familiar what marginal plants prefer lower pH conditions. Collect some of those plants and transplant them on your shorelines. Be a water gardener.

I agree with Bill. Get the soil tested for pH. I would run two tests. Test the soil in the pond basin, and test the soil about 30 feet away from the pond. You might have low pH there too, and raising that soil pH will allow plants to grow faster, and those plants will also help stabilize the banks. I get soil tested at the local farm fertilizer supplier (NOT a "Tractor Supply" type of place). Once the soil test is back, they can tell me how many tons/acre of lime to use. They also have a spreader cart that can handle either 5 tons for the small one or I think 10 tons for the large cart. It runs off a PTO on the rear of the tractor and the wheels on it pull a chain type belt that dumps the lime onto the whirlybird spreaders. There is a gate at the back that you open a certain amount to apply a certain tonnage per acre.

Article - Jul-Aug 2024 pg 22-24. Snakeheads: Are they Monster Fish? by Dr. Wes Neal MS State Extension Fisheries Specialist. Explains the pros and cons of these invader Snakehead fish specie along the eastern seaboard.

Esshup and Billy Cody,

I decided to try ag lime and see what effect it has on the low ph of 4.5. I spread one ton between the banks and in the water. I’ll check the ph over the next couple days and see what happens.

Snakehead are amazing! We use heavy striped bass fishing gear for them around here. Most fish are around 28” and they strike in only inches of water. They fight similar to a striped bass too, will nearly pull you out of a kayak.

They would be a really neat fish to keep and observe, they have some many unique characteristics. Two of my favorite characteristics are that they will take gulps of air from the surface, and they look like dragons when they dive through the surface of the water like a dolphin would.

Two main problems with the snakehead though as a game fish, their teeth are serious just like a pickerel/pike/Muskie. The other problem is that it is illegal to transport them alive. It’s been an ongoing debate to whether they have negatively effected the other fisheries. We have definitely seen a decrease a frogs in fresher water, but I personally haven’t seen any change in brackish waters.

Just the "illegal" part would deep me from stocking them, no matter how well I liked them. FWIW, if the violation is considered to be a violation of the Lacy Act, you might want to look at this:

Key points about Lacey Act fines:

Civil penalties:
Can range from $250 for minor violations to $10,000 for more significant breaches.

Criminal penalties:
For serious violations, individuals can face fines exceeding $100,000 and potential imprisonment.
Corporate penalties:
Corporations can face fines up to $500,000 for Lacey Act violations.
Factors affecting fine amount:
The market value of the protected species involved, the intent of the violator, and the severity of the violation.

As for the lime, I don't know how fast it will show up in the pond water. I know in soil, the farmers apply it about 5-6 months before they will be planting to allow it time to work on the soil pH..

Yeah, there is no way I'm transporting live snakehead. Plus, they are too good eating to not cook up. Within a few more years I'm sure they will have naturally spread from the Chesapeak to the Atlantic anway. Snakehead are pretty unstoppable and nearly ALL of our waterways in DelMarVA are connected by ditches.

Well, now its a waiting game on the ph. Since yesterday, the PH went from 4.5 to 4.75.

Back to the topic of fish for this thread;

An additional idea.
Another single predator fish, in addition to or in place of those mentioned above, that you could add to the population of reproducing yellow perch(YP) would be ONE chain pickerel - native to the east coastal area. . Doesn't get overly large and thus would consume lots of smaller YP each year. The number of predators that the pond would need to keep the YP from overpopulating will depend on how well the YP reproduce (recruit young ones) to add new YP per year and how many YP of any size that you harvest each year. Your fishery may only need two of the aforementioned predators. If small YP appear to be too numerous then each year add an additional single specie predator. Your management goal will be to monitor each year the relative numbers and sizes of YP in the pond to insure the YP are growing well with all sizes present and having some large adults shown by the sampling techniques: angling, seining , trapping. Together all five of the single specie predators would be capable of eating 1500 - 2000 small YP per year that is probably too many small YP losses for your small 1/3 ac pond.

Bill Cody,

I'm pretty sure YP and Pickerel is where I am headed. So far my ph, it has rose from 4.5 to maybe 4.75 after one ton of lime. Many people around here hate pickerel, by I think they are so neat, like baby muskellunge.

I've been making a plan to catch/gather some local YP or buy a batch from the local hatchery. (White perch are plentiful around here too and acid tolerant. But they aren't as pretty as YP.)

I think the goal is to raise one big predator of a few different species. Pretty much raising pet predator fishes, but I wont be hand feeding the pickerel!

I'll likely start with the one pickerel, then work towards more ph neautrel fish like a bass. I read that rock bass can handle the acid too.

I'm dreaming that after my vegetation fills in, that maybe the ph will be less radical and I can have a pet hybrid striped bass!

IMO - leave out all white bass and rock bass. Those questionable species, if needed or desired, can be added later when the fishery is mature, reproducing, and established. IMO whenever you later add a new species remove some (2-4) of the existing similar sized residents for each new specie added. This is to reduce competition so the new specie has a chance to survive and thrive.
Remember initially add one of each different predator in this small pond. Monitor the forage and panfish species for several years then make the changes as needed in your 1/3 acre.
We are here to help with good experienced advice to help improve the fishery balance when you want or need some pond mgmt and fishery opinions. Non-reproducing Hyb striped bass are very good at controlling YP. Need more predation add a few more HSB; too much predation, with too few YP, remove some HSB. You control the predatory pressure on the small panfish.

Regarding the lime. The more surface area of the lime that comes in contact with the water, the better. Powdered ag lime blown across the surface works faster than dumping it in one or two spots.

Bill Cody and Esshup,

I’ve applied a one ton of lime across the surface of the pond and its banks, and the ph didn't budge. Given the acidic nature of the pond, I’ve decided to focus on acid-tolerant species rather than trying to adjust the pH.

Over the past few days, I’ve been collecting true acid-tolerant species that thrive in a pH of 4.5. So far, I’ve caught Eastern Mudminnows and Pirate Perch in a nearby swamp. I also found some snails and crayfish that seem to be doing well in the 4.5 pH. According to reports, the same swamp waters also hold redfin pickerel, which are a bit rmore rare than our usual chain pickerel.

I'm curious to how the Eastern Mudminnows and Pirate Perch will comptete with my Bull Minnows (brackish), Fathhead Minnows, and Easter Mosquitofish. Spawning should slowly start this week with the temperature near 70 each day. Once again, a waiting game.

I'm going to hold off on the YP and any predators until I see schools of baitfish. Fingers crossed because it seems that the swamp type minnows reproduce more slowly.

With the pH you are seeing, the food chain will be severely limited due to the low level of phytoplankton that will grow in that pH water.

Limited nutrients in the pond can on one hand be a good thing. Utilizing species adapted to living in low pH is a very wise decision.

Routine liming not only increases the food chain it also increases the amount of plant growth that can sometimes be unwanted. Nutrients feed the ENTIRE pond system. Generally - The more nutrients present the more production produced from plankton to predators as this assumes adequate alkalinity with somewhat higher pH.
When having low pH (alkalinity) this just means one cannot produce as many fish pounds per acre. Usually low pH waters are clearer compared to water with higher pH. However with low pH the pond can still produce big fish just not very many of them; maybe only 1 to a few per acre depending on fertility of the system. To work around low pond pH and fish productivity one can feed the fish a good quality food and this increases the fish poundage per acre in low pH water providing the species are adapted to living at low pH.

Hoping your pond does well and please return here for some periodic updates about your pond's status. Thanks for posting.