Pond Boss Forums GENERAL QUESTIONS Muddy water Lbs of Alum to Dissolve in 200 Gallons?

I have a one acre-foot pond and have determined I need to apply 150 lbs of Alum. I have a 200 gallon tank in which to dissolve the alum and spray it on the pond.

How many lbs of alum should I try to dissolve in the tank before application? Can I go as high as 50 lbs at a time?

Note I am off grid and will be using the pond water to mix with the alum.

You could dump it all in at once, but you would need to keep it agitated while you exchanged water in the tank to spray it out. i.e. 2 gasoline powered pumps.

Watch the pH of the water in the pond. Too much of a pH change could kill the fish.

What is your alkalinity and hardness of the water?

I have very limited resources. 1 pump. 1 tank and a pond. I need to mix it, them pump it to the pond. No other options.
No fish to worry about. It is a pond for swimming, and I will pay attention to ph afterwards.

Then I'd still put the 150 pounds in the tank, pump in the water. Stir, until it becomes a saturated solution and pump off the top, not sucking up any sediment. Keep repeating until the sediment is all dissolved.

Spray the dissolved alum over as much of the pond surface as possible every time you pump out of the tank.

Thanks for the advice!! I will give it a go soon.

Please come back afterwards and let us know how the process went and how many pounds you needed to achieve your goal.

I plan on documenting the process with pictures, and posting them here. It will probably be a week or two before I start. Still waiting on the pond to fill up after draining it to clear dirty water. Here is what it looks like now.

[img]https://drive.google.com/file/d/1th4PIj8qvFCPphnWnYWArGcouuOwJhUe/view?usp=sharing[/img]

So much for the "Insert Image Link" functionality!

The link worked for me. If you want to insert a picture I am pretty sure it has to end with .jpg for it to work correctly.

Alum does not dissolve into water. Liquid Alum is a highly acid liquid....FWIW, 50 pounds of dry alum can be dissolved into 55 gallons of acid that is heated to 200 degrees. Agitation is needed to create a slurry that is then sprayed when using pond water

Rex, It's good to see you here again.

Thanks Al !!

'bout time you showed up again Rex!!!

After Talking to Rex a few times, I started using his advice in treating some local ponds-including my own. One thing I found when using the dirty pond water to mix solution, you can get a funky reaction in the mix tank without some super aggressive constant agitation.
Concentrate 2/3rds of your Alum (80-100lbs) into the deepest 1/3rd of the water, then use the last bag to spray the outer-shallowest water. I still think using hydrated lime is a good idea at half Alum rate because it also aides in the clearing/binding process.
I've had great luck with Alum but I had some great direction from Rex on my applications so if he chimes in, follow his advise.