Is it most beneficial to aerate in the hours just before sunrise for a system which does NOT have sufficient power to run all of the time?
For discussion, consider a solar system that can run 4 hours a day during peak sunlight in the early afternoon versus a system that includes batteries and a timer than can run 3.5 hours (due to system losses) in the period just before sunrise.
(The secondary question would then be: Do the experts think the additional expense of a battery bank is well worth the benefits to the pond?)
I think DO is lowest just after dawn. As the light increases, eventually photosynthesis outpaces respiration and DO rises. It is a common practice in commercial aquaculture to begin aeration well after sunset when DO levels reach the minimum desired and stopping aeration some time after sunrise when the production of DO by photosynthesis warrants shutting it down. In commercial aquaculture there is incentive to reduce energy costs associated with the crop and this results in the best bang for the buck.
It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers
Depends on what the situation is and why you want aeration. I see several results from aeration-depending on the type- several things can occur. You can raise the water temp, you can lower the temp, you can add some O2 and you can limit anoxic water from forming. Your highest BOD will likely be in late summer-early fall with plants starting to decompose, wild planktonic swings, high fish biomass and somewhat warm temps yet. Choosing 3-5-4hrs of run time will be determined by the amount of what you have that you are trying to affect the most with aeration. Most times of the year you can do more damage by running too long of time period, but as I said, it depends why you need it. YP vs LMB or BG. YP handle pretty low DO but suffer greatly in higher temps-what would be comfortable for sunfish. Having a shallow hypolimnion can benefit species like WAE, YP, etc. so with that said, if I had to choose 3.5hr to run it would be the 3.5hrs prior to sunrise. There are some benefits to running mid-day at certain times but it's short. I think the best bang for the buck, buy batteries.
This may or may not be on topic for this thread but what are these little bubbles on the surface of my pond? They seem to appear early early morning and are gone by 10:00am (once the sun hits them for a few minutes) Noticed them Friday and Saturday morning but not this morning No aerator or fish currently in the pond
I believe that to be a gas off of decomposing material at night. I think heat and time of year have something to do with it and I can't say that it's abnormal. It seems to be present in areas that are extremely calm or down far enough the breeze does not move it as it does in other ponds.
Depends on what the situation is and why you want aeration. I see several results from aeration-depending on the type- several things can occur. You can raise the water temp, you can lower the temp, you can add some O2 and you can limit anoxic water from forming. Your highest BOD will likely be in late summer-early fall with plants starting to decompose, wild planktonic swings, high fish biomass and somewhat warm temps yet. Choosing 3-5-4hrs of run time will be determined by the amount of what you have that you are trying to affect the most with aeration. Most times of the year you can do more damage by running too long of time period, but as I said, it depends why you need it. YP vs LMB or BG. YP handle pretty low DO but suffer greatly in higher temps-what would be comfortable for sunfish. Having a shallow hypolimnion can benefit species like WAE, YP, etc. so with that said, if I had to choose 3.5hr to run it would be the 3.5hrs prior to sunrise. There are some benefits to running mid-day at certain times but it's short. I think the best bang for the buck, buy batteries.
Thanks Snipe, lots of good stuff to chew on in that reply!
Not sure of the fish population for the potential new pond yet, because I will have to see what the clay distribution at the location allows me to make in terms of pond characterisitics.
Let's assume a conventional LMB/BG pond for the sake of discussion. You definitely know the Kansas weather swings that my pond would be subjected to. I think I am most worried about a low DO fish kill occurring after we get a little cool weather in August (to start some decomposition in the pond) and then get a high pressure dome for 4-5 days with temperatures of 105 degrees and very light winds.
If you (or others) come back to this thread, is that my most likely scenario of a fish kill that could be avoided/mitigated with some aeration AND running my diffusers a little off the bottom in the 3.5 hours before sunrise would be the best solution to that problem?
Any additional comments about OTHER scenarios would also be appreciated.
Here's where the batteries shine.. If a system such as you describe, shows it's face, if you are already running 4 hrs in the am, with proper storage you can run all night during these events, keeping any anoxic layer from forming in the first place, so there's no shock to the system, or at least minimize the impact if a roll does happen
