I know trout generally do not survive the summer in southern ponds, however I'm wondering if I might be able to get some to survive in my little pond if the water temps stay cool enough. My pond is 1/8 acre with a max depth of 8.5 ft and is spring fed although the spring all but dries up in the heat of summer. I also run aeration in it and use dark pond dye. I took the temperature of the pond in the middle of th afternoon today when the air temperature was 98 , surface temps were 85 and the temp at the bottom of the deepest part was 70.7. Would rainbows or browns be likely to survive if the temperature in the deep end stays in the 70-72 range in the heat of summer?
Dissolved oxygen is more important that water temp. Yes, the cooler the water the more D.O. is possible but in most cases it seems 60 degrees is about max for comfort in the right situation for that 60 deg water to hold the DO required.
My guess would be no. My pond is deeper, with cooler water (below 65) but the DO is too low even with aeration but I'm not rolling all of the deeper water to the surface so I'm not mixing the upper layers to warm up the entire depth-on purpose.
If rolling the entire pond, the temp will be very similar top to bottom so the lower layers will be the same as the upper-maybe not 85 as the surface is, but likely not but a few degrees less.
Snipe, although this is off topic from the original post, I'd like a quick run down of how you aerate your pond. I've been working on horizontal aeration with circulators in an attempt to keep deeper water cool. Was wondering if there was any info we could learn from your situation.
Im looking to add a 10,000 gph pump for a waterfall in addition to the aeration, do you think this would increase the oxygen level significantly?
Freg, I think that will still affect mixing of high surface temp water, as-in the waterfall supply still has to be pumped from somewhere and put back somewhere-if that makes sense..
If you pull from the bottom it will mix, if you pull from mid depth I think you'll still have an oxygen poor lower level of cool water. I can't prove that but it is my opinion.
I circulate bottom water through a pump and a venturi after the pump sucking air into the stream of water and it's discharge is about 1' off of bottom but pointed slightly upward. As for what the DO level is I can only assure it's not dead water but I don't know that it's enough to support trout..my guess is no. I have no way to get a sample at the bottom to test. I can only test at arms length deep. The problem with this is when the water flows out at bottom the air is still released bringing some flow with it but it seems to be minimal. My top to bottom temps are about a 25-28 deg spread.
This is the sort of situation where nanobubbles might help, as they stay in the coolest water. Worth looking at recent articles in PB magazine on the subject. Personally, I'd love to be able to keep rainbows and tiger musky if the tech & budget make it doable.
Snipe, interesting on the venturi system. I may need to pick your brain on that at some point. Currently I've added one Kasco de-icer/circulator and I am in the process of mounting another. I'm creating a 'lazy river' effect all the way around my 2/3 acre pond, or what I hope is a horizontal aeration system. Amazing how much water gets moving when it is pointed parallel to the shoreline. I need to get DO and temp readings throughout the depths of my pond to see what type of impact it is having there. So far I've noticed 3 positives 1) less stagnant water/fewer mosquitos 2) major plankton bloom and 3) the filamentous algae has been mobilized and seems to be decreasing in mass. Also, I like that I can push the FA off of my beach/swimming area. Edit: 4) I also like that it seems to mobilize detritus in the shallow outer portion of my pond that the traditional vertical aeration system doesn't move. I'm hoping this system is beneficial for species that tend to thrive in streams... Smallmouth, spots, etc.
Anthropic, what type of temps do you have in your pond? I'm testing out some tiger muskie up here to see how they respond to my water. One of the reasons to go to a horizontal aeration was in hopes of preserving my thermocline. I need some data, but so far I believe my TM are thriving. Or at least they did well through last summer.
How far away from your circulator can you still see water moving? My plan for my pump is to actually split the water flow with some of it going to a water fall and some going into my spring to create hopefully some of the benefits you have mentioned.
With my 1hp Kasco I can see water moving throughout my entire 2/3 acre pond. And I can see little swirls, or a vortex of water over 100 ft away. I will start a post regarding this when I get everything set up. Snipe's venturi set up has me doing some research on systems I may be able to incorporate also. In particular this set up......
https://www.youtube.com/watch?v=IZyrL5Ojqpo
NEDOC, you should have a good chance of keeping TM alive in Nebraska. They flourished in a private lake I used to fish in central Ohio. Hybrid vigor, more heat tolerant than either pike or muskie.