I'm just completing a 3 1/2 acre pond about 15' feet deep at dam and averaging 5 to 6' of depth from mid to upper end. I had a soil test done and it reported 2 tons lime per acre. My question is do I lime the pond bottom at the same rate? Should I spread it evenly and disc it in as I plan to do on the ground surrounding the pond or do I just add it to the pond using the bucket of the tractor and let the water as it fills disperse the lime?

Congrats on the new pond!

I am not an expert on the lime requirements for ponds. However, the purposes of adding lime to agricultural ground versus adding it to ponds are different.

We have several experts on the forum for your topic. Hopefully they will comment on your thread.

P.S. Have you read any of the good threads about adding structure to your pond? It is much easier to emplace BEFORE your pond fills.

Good luck on your pond project. 3.5 acres and 15' deep sounds like a beaut!

Arkie, I initially went with two tons per acre per expert advice. This seemed low, so later I added another two tons per acre. At the time I intended to disc it in, but my pond builder told me that wouldn't be necessary. Wish I had insisted!

Even a total of four tons per acre turned out to be insufficient, especially as it was just placed on the future pond bottom without disking. Very low alkalinity & pH forced me to lime within 15 months of filling. Now I do it every other year.

You just about can't lime & disc too much, especially when first starting. Much cheaper & more effective to do it before your pond fills!

Adding lime in an area of acidic dirt (watershed) is not a one-time event. I have never had anyone suggest discing it in. Using ag lime spread it as best you can over the pond bottom (perfect is not required). Once treated the lime will have a curve of effectiveness - it will take time several mths to get the water alkalinity up and will then stay that way for a while then start declining. Depending on location the application can last from 1 yr to 4 yrs. You are treating the water not the dirt. Lots of good threads on this. If this is a new pond /dry ground, then put twice as much as suggested. You will be saving some work by doing that.

Thanks for the answers. I'm having 25 tons of Ag lime delivered, not that I need it all right now but lots cheaper by the truck load.

I have a similar question. Does it make any sense to lime the pond if the water is constantly being replenished thru a pipe inlet and another pipe outlet? It seems like the limed water would just flow out as unlimed water is flowing in. The test results of my water source around 5.4 pH. My pond is 1/8th acre.

kevin, the answer would depend on how fast water flows in and out. Faster would deplete lime faster. You might be in situation where feeding would be better than liming. Check alkalinity, as it is more important than pH.

Flushing is a problem with ponds like yours and adding lime. My 2 cents - with a 5.4pH I would add a bunch of lime when flushing is at its smallest if I could afford too. That pH is hard on fish and water quality - see chart 2 noting wide swings in pH cause stress on fish.