Pond Boss Forums GENERAL QUESTIONS Water chemistry high ph green algae

hello. new to this deal. have a three year old pond about 4million gallons, lined, crazy...good bass and bluegill stock...been treating with natural bacteria since day one. had rough hot summer with heavy pea green and some string in last month or so....worst is ph high at 9.5 or so....am working on fish friendly solution to lower ph??? thanks much

Welcome, amerpond!

Do you know why your pH is so high? Do you use well water to fill the pond? Is there something in the soils that gives other ponds in your area a high pH?

Fascinating, because I have the same situation. For me it comes from high pH well water interacting with a huge photosynthesizing plant community. My pH can go up over 10. Alum helps. Do you have any experience with alum?

I can't figure out any external source for high ph...no experience with aluminum...looking for what's most fish friendly...someone told me a long slow treatment of muriatic acid can work but I'm waiting for further information...thanks

Alum, or aluminum sulfate will clarify many ponds, and acidify all ponds. You can lower the pH as much as you wish, fairly economically, with no detrimental effect on your fish. Here's a link to a previous thread.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Main=5386&Number=49373#Post49373

thanks again...i'm working with bacteria from strata international and will forward to them for their thoughts as well.

This is a very good SRAC article on turbidity control. Note the quoted part.

http://srac.tamu.edu/tmppdfs/144249-460f...bee5c7864263371

Although not nearly as effective

as alum, gypsum also can be used

to control turbidity but without

the loss of alkalinity. Gypsum

must be added to achieve a concentration

of 100 to 300 mg/L for

effective turbidity control. For

most ponds, gypsum application

rates will range from about 1,000

to 2,000 pounds per acre (Fig. 4).

In hard-water ponds (calcium

hardness greater than 50 mg/L),

the water is nearly saturated with

calcium and gypsum may be ineffective.

In that situation, alum will

be the only effective coagulant.

All the coagulants mentioned can

remove phosphorus from water.

As phosphorus is an essential

plant nutrient, it may be necessary

to fertilize the pond after treating

On occasion, phytoplankton

and clay can mutually

coagulate, so fertilizing to start a

phytoplankton bloom may also

clear water of suspended clay particles.

Organic matter such as chopped

hay or cottonseed meal can reduce

clay turbidity in farm ponds.

However, large amounts of material

must be added to the pond,

which may deplete the dissolved

oxygen as the organic matter

decomposes. It may also be difficult

and costly to transport and

uniformly distribute large

amounts of organic matter.

Almost any acid will work. Most acids occur naturally and are fish friendly if diluted. Muriatic is an old name for hydrochloric, and will work. Acetic and sulphuric will work. Alum is a good source of suphuric, and works great. Dilution is the key.

Hay is also a good source of acetic, lactic, and tannic acids, but can cause a drop in dissolved oxygen. If you already have a big plankton bloom, I wouldn't go that route.

This may help explain the chemical relationships.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Main=9475&Number=99999#Post99999



M Spinhirne
Lunker


Registered: February 16, 2006
Posts: 107
Loc: Montgomery, Texas
(209.173.79.95) Something doesn't sound right. At a pH of 10, hardness solubility should not be 100 ppm as CaCO3; certainly not as ion. Alkalinity could be this low, but would likely be higher unless you are pulling from a lime deposit sand. Hardness at twice the alkalinity indicates calcium chloride or sulfate, or magnesium salts of the same. High levels of non-carbonate hardness would typically be the case at pH ranges nearing neutral, not above 9.0.

The pH at this level is detrimental to fish growth and health. Natural waters do not stay at this level unless they receive additions of lime, caustic soda, or soda ash. Lime and soda ash are naturally found soil deposits in some areas. I have not heard of that being the case around your area of Texas. The only area in Texas I am familiar with that has wel water that high in is water is near College Station, where well water runs 9.5 pH, but low hardness from the natural soda deposits. This water is extremely soft (low in hardness)from the high pH and high sodium content (solubility of hardness salts at 10 pH and ambient conditions is less than 60 ppm due to retrograde solubility).
I would check the pH out of the well. If it is this high, you will need to add sulfur salts such as ferric sulfate to lower pH with out lowering alkalinity. Once the pH is lowered, CO2 solubility will increase, and alkalinity and hardness levels will stabilize. _________________________
Mike

thanks for the info. I did test the well and it was great at 7.6 so not the culprit...I'm now looking at some lawn treatments that are pretty far away from pond edge and the pond is lined so it remains a mystery...I think we will be starting a slow muriatic acid treatment...and then reintroduce the bacteria I've been using..stay tuned...