Pond Boss Forums AERATION Should I aerate? When to stop aerating

I want to keep running my aerator for as long as possible. At what temperature should the water be when I turn it off for the season? I'm in Michigan and the pond will get a thick layer of ice, it's 1/4 S.A. and full pool is 13' deep. I have a ton of minnows (BNM, SFS) and will be stocking some YP, RES and WE in about a week.

At 11' - 13' deep does the water temperature at the bottom of the pond drop significantly in the winter? For example, if the deep water is around 50 degrees when I shut the aerator off will the deep water stay warmer through out the winter without aeration?

I run the aerator all winter long, switching from the deep diffuser to a shallow diffuser that is set about 1/4 of the total pond depth, and close enough to shore that the ice is gone all the way to shore.

You'll probably see bottom temps between 41�F to 37�F.

Thanks for the guesstimate! So to a degree if I stop aerating while the water temperature is relatively warm this will result in a little warmer pond in the deeper areas over winter?

I won't be moving my diffuser.

Not really. Water is densest at 39�F., so when the surface water reaches that temp, it sinks to the bottom aeration or no aeration.

Ok.

Well my water is green, it has been that way all summer. I'm assuming the algae in there will die with the cold temperatures making the water clearer(assuming my water clarity problem is due to algae), is this true? Is there a chance the algae won't die? I imagine the bacteria I put in there will die but I've seen there are some strains that can live in colder conditions, unfortunately I don't know what strains I have. I'm trying to decide when to pull the plug on my aerator.

What's the coldest temperature I could hold out to?

Yeah, most of the phytoplankton that is alive in the warmer water will die, but enough will be alive to repopulate the pond next year.

As for temp, how thick is your winter coat, and do you have good boots and gloves? Water temps in the 40's-50's would be fine, although I think running it in the winter is even more important than the summer up here where we can get heavy snow cover on the pond.

Abundant and common species in the warm water could likely develop reduced densities. But if nutrients are present, then species adapted to cold water could easily increase in number to keep phytoplankton common or even abundant. I have seen blooms in winter's cold water and even under the ice. Light intensity and nutrients determine algae density no matter what the water temperature is. This assumes adequate alkalinity.

A common time to stop aeration is when the water gets 50F or high 40's or near these temps. Then the pond usually fully circulates especially if it receives some wind action. Fall circulation stops when ice cover forms and water is typically 39F from about 14"-20" to the bottom.

Thank you so much. I'm learning a lot here.

In reading thru this topic, I just tested the water temp. at 4' depth in my 3/4 a. pond, it was 40 degrees. Under these circumstances it sounds to me like I should turn off the aerator and restart it at a later date to maintain whatever warm waters for as long as possible?
When do I restart it? We have black crappie, bg, and a few lmb. I don't intend to move the aerator that is currently at 12'. But if necessary I would, to prevent a winter kill. We of course, get lots of ice in the winter and in the past have been able to keep a 6' hole open thru the -20 and -30 temps.

Up nort dere, I'd move the diffuser to shallower water - 4' depth to preserve the warm 39�F water when the pond is iced over and you're running the diffuser to keep the water open.

If you have a float and a rope marking the diffuser, it should be an easy propositon to drag the diffuser to shallower water.

Will attempt this hopefully everything holds together, the 4-diffuser is weighted w/gravel and we do have a rope and float attached.

I don't think moving a diffuser is so easy, at least for me. I have a similar situtation, 12' deep, 4 head diffuser weighted with gravel and weighted line. I also have to use a boat and paddle to accomplish this and this time of year is generally very windy.

My previous pond was just as deep and I didn't aerate it at all, I had my first fish kill at the 20 year mark after a winter. I think the amount of muck buildup makes a difference, if you have 2' of muck after many years then you have less depth and water in the pond.

I'm not running my aerator this winter.

If you don't run the aerator then how and when do u restart it next year? The gases and low do will be a problem for the fish on startup.

A little at a time. Increasing the run time every day for several weeks. Several threads here on the subject.

Nils, I start up my aerator a little at a time in the spring like ewest said. The first day I run it for 15 minutes, 30 minutes the second day, 60 minutes the third day, 2 hrs the next (doubling the time each day) etc. The whole process takes about a week.

If your pond is older with a lot of muck you should pay attention to how it smells while the aerator is running at startup. If you still notice a strong odor when pumping on the third day, I wouldn't double the running time until things improve. If you notice the odor is gone then you can continue on doubling the time.

If you run your aerator 24/7 during the spring/summer/fall season you should get less muck buildup reducing chances of a winter kill and an easy spring startup. I really didn't notice any odor when starting up my diffuser after last winter but my pond was re-dug 2 years ago and is still pretty new. I also add beneficial bacteria during the season and I haven't noticed any muck build up yet.

I didn't relize any smell either. My pond was 30 yrs old and I could smell funk when I walked in the shallows.. I'm amazed at how much leaf muck has dissapeared in a couple years of running. I actually have solid clay spots showing in some shallows which were covered in black decaying leaf muck.. I think next year I'm gonna figure away to stir up my really built up nasty muck areas to speed decomposition and decay maybe one cove a month..

I am with you essup, I took my tractor and dug a nice hole right at the water line now, (pond is down about 4') so if we get rain the aerator is by the shore. I have a lab with the brains of an ant. LOL I hope if she goes through the ice it will be by the shore.

I moved mine closer to shore so there is open water to shore. I almost lost 2 of my Springer Spaniels when they went swimming in January in the open water after the geese that were on the pond. I had to really scramble to break the ice so they could swim close enough to shore so I could grab them and get them out of the water. They were too cold and tired to climb up on the ice by themselves. Temp was near 0�F with wind chills in the -20�F range. Took 20 minutes in the shower under hot water before they stopped shivering.