Pond Boss Forums GENERAL QUESTIONS Muddy water How to apply hydrated lime after alum

I did an alum treatment on my 1/4 acre pond a few weeks ago and it made a huge difference in water clarity. I used a 330 gallon IBC tote to mix the alum with pond water and then a 2" trash pump to dissolve and apply the alum.

After the alum I went to dissolve the hydrated lime in the tank and had alot of trouble. It seemed to fall to the bottom of the tank and not mix with the water even after having the trash pump recirculating back into the tank.

Anyone have any tips or tricks to get the lime to mix with the water?

I am asking because I plan on applying alum to my 1.25 acre pond this weekend.

I'm not sure what would work unless you could keep it agitated or have water stirring it up on the bottom. Lime is a rock, and it inherently sinks. When I spread it, the bottom of the pond is solid white after it falls through the water column.

Hydrated lime is only moderately soluble in water.

You may have to get a concrete mixing tub (cheap at big box hardware store) and physically agitate the material with a paint mixer attachment on your heaviest drill. Then suck it into your tote with your 2" pump.

For a bigger job, a better option might be to rent a concrete tub mixer and use that. I can rent those pretty cheaply, and they sure are handy for concrete work. (I don't know how well it would mix your lime, but most have some blades in the tub, so it should provide good mechanical agitation of a heavy material.)

Another thing that might help is to use the hottest water you can access. The solubility of your lime is about 4x higher in boiling water compared to room temperature water. Maybe crank your water heater to the highest setting and use that? That might be worth the effort.

Finally, how finely ground is your hydrated lime? Grinding it considerably finer will greatly increase the surface area and substantially increase the solubility. If you are going to have to do it every year, then it might be worth the investment in some grinding equipment?

Good luck on your pond treatment.

Make sure it's type S true hydrated lime. I rinse water tank out good after Alum treatment but I treat 1/2 pond with Alum, then treat that part with hydrated lime, just pour the powder out the side of the boat. You can mix it pretty well in water if it's the right type of lime in powder form, I've not been exposed to any other courser type, never had an issue with agitation or keeping it suspended in a tank.. agitate and shoot, agitate and shoot.