Had some tenth acre hatchery ponds dug in May this year. Want to top them off with water from a established pond. The established One acre pond is 15 ft deep at deepest, no airiation, surface temp 87deg visibility 24 inches.
Will it be helpful or harmful to the established 1 acre pond if i pump water from 9 ft below surface?

Do you already have organisms in the hatchery ponds?

If not, then I would wait a little longer and top them off in the fall.

What is the total volume of water you will be drawing from the 1-acre pond?

Drawing some cooler water from the 9' level will allow your 1-acre pond to heat up a little more if you get another bad heat wave. The warmer water holds less dissolved oxygen. I would hate to heat your pond during the hottest time of the year without aeration.

Does your 1-acre pond have a good water source? (Will the water you remove probably be replaced soon?)

Those are the safe questions/answers above. In reality, it will probably make very little difference to your main pond. OTOH, why take a small but significant risk for not much gain if you could do it more safely later?

Thank you for answering.
the ponds I'm adding to dont have life in them yet.
Total draw from the one acre pond is around 150000 gal
I purposely dammed up the spillway on the one acre pond added 18 inches to the depth.
My idea was to use the extra water to fill up the new dug ponds as we got heavy rains.
Had no idea the rains wouldn't come till August.
I will only be drawing the pond down to its normal level.
Do I need to take the water from deeper in order to remove the deadly non oxygenated water.
I was hoping this might remove some of the stratified water.

I think I misunderstood your question a little. Thanks for the additional info.

If your 1-acre pond had an average depth of 8 feet, then your water volume is 2.6 million gallons. Pumping out 150,000 gallons is about 5.8%. Not a trivial amount, but not huge either.

At this time of year AND without aeration, your pond should be stratified. The bottom water you take will have very low oxygen levels. It should also have more nutrients than the warmer surface water. You probably want the nutrient-rich water in your hatchery ponds!

Therefore, if your question was mostly "what depth should I pump water from?", then I agree that 1-2' off bottom in one of your deep holes is a good source.

I suspect you will be fine pumping the water as you planned. However, if you wanted to be extra safe, you might pump it when you see a rain in the forecast.

How are you going to aerate the water in your hatchery ponds? There are some threads on Pond Boss about aerating during the pumping process. I don't know if that will be sufficient for the requirements of your hatchery projects.

Good luck on your big upcoming projects!

If you've had no new inflow, It's hot and you have no aeration in pond you want to pump from-from 9-10' deep-you may be pumping toxic water. If you are using it to fill dry ponds with no existing life, that may then be Ok..

Make sure you have a very good small micron filter on the intake side or you might be bringing unwanted critters to the hatchery pond from the main pond. Yes, small fish and organisms can survive going through a pump.......