Pond Boss Forums INTRO Questions & Observations The Big Chill: How hazardous to our fish?

Checked weather forecast for my BOW: 86/70 this Monday, gradually cooling down 23 degrees by next Monday to 63/47.

Question: Supposing this forecast turns out to be right, how much of a turnover/stress threat is this cooldown for my fish? Does it make any difference that it is spread out over a week, as opposed to just a day or two?

I know my TP will survive as water temps won't fall below 55, but they will undoubtedly become sluggish and maybe the LMB will feast. Also on the plus side, I can begin fishing for the HSB without so much fear of killing them.

But how worried should I be about the chill? And for those who live north of me, where the chill will hit even harder, how should they prepare?

A cold snap is much less worrisome if it is spread out over more days compared to "overnight".

We, here in Mo, went through a cool-down a couple weeks ago (20 degree drop over the course of about 5 days then leveled out for many days). My pond (with aeration) only dropped about 15 degrees over the duration of the cold spell, but the climate warmed back up. The pond water temps seemed to lag behind the cold front by a day or so. Meaning that if the air cooled down 5 degrees today and continued to cool down 5 degrees per day, the pond would follow a day behind with water temp drops. This makes sense as it should take the water some additional time to lose it's warmth to the atmosphere. I did switch my air time to days instead of nights to help warm the water during the day and avoid cooling it at night. This cool-down and change in air schedule really messed with the fish's routine, however. They just slowed down rwt feeding and a bite on a lure was next to impossible.

According to the forecast, we can expect a 30 degree drop from today's high to Thursday's. I will leave my aeration on during the daytime to keep the water column temps consistent throughout the column until the air temps become colder than the water temps. Then the aerator will be turned off until spring (unless I need one of the diffusers for ice-off). I think I will quickly phase the aerator out because the air temps may get below the water temps during this cold snap.

I cannot say how much we need to be worrying about it as this is my first fall with a pond full of fish. I will be monitoring the air and water temps to see what happens.