Pond Boss Forums AERATION Should I aerate? Summer fish kill

I have a 4-5 yr old pond...stocked with Bgill'bass,catfish...... Fish have always been sassy heathy... Doing well.....36 hrs ago everything seemed fine. Yesterday we started seeing dead fish all 3 species. Pond about 2 acres. One very shallow end. Fighting algae used biologically on it about 8 days ago..... Borrowed an aerator from neighbor trying add oxygen.... Can't get any conservation help until Monday thanks for any help

I'm sorry this is happening. Did you treat the entire pond at once? If you did, this may have been your mistake. What did you treat it with?

I think your doing all you can do right now if your aerating efficiently. What is your aerator set up like? A rubber membrane diffuser works the best. I'm not an expert here and others might be more helpful.

Hello, sorry to hear about your trouble, and welcome to Pond Boss.

Can you give a bit more information? Specifically, what exactly do you mean by "fighting algae used biologically"? Recent weather conditions, especially anything that might interfere with 02 production by plants, such as clouds, increase in murkiness of water due to runoff, etc would also be useful.

This time of year, many ponds are getting really warm, which reduces the amount of dissolved oxygen the water can hold, and consumption is high as there's a lot of biomass present....there's also a lot of oxygen production from plants and algae, but sometimes not a lot of margin between the two, so if something pushes just a little to far in either direction, that is increasing consumption [for example from decaying plants] or reducing production [interfering with photosynthesis], the pond can go off the rails in a hurry.

The vast majority of fish kills are caused by 02 crashes, so look in that direction first. There are occasional kills caused by blooms of algae that are toxic to fish....what "biological" was used?

More dying fish.....what it looks like to me is I am killing so much algae that we have changed the water from nice green to brown..... Any ideas on how too reverse? Running a pump fountain off of a generator..... Thanks for any help

I used LSC and 900 for biological muck reduction....9 days ago. Been very chilly here last couple of days. 50 at night.... Now warming back up. Most noticible to me is change in water color.... Now brown... Not green

Not familiar with either one...what's the active ingrediant or biological?

Sure sounds like a DO crash, brought on by reduced 02 production from loss of photosynthetic organisms and increased 02 demands by breakdown of dead algae.

I don't know of a way to reverse this. Only thing you can do at this point is add oxygen as best you can, fountain will help a little, aerator will help some, but best is aggressive surface aeration.

Good luck.

Evem better than the fountain is a surface agitator for rapidly putting O2 into the water. Aqua-Master, Otterbine, Kasco, etc make them.


If you can take something, anything that splashes the water (the more violently the better) that will help. An outboard or trolling motor with the prop high enough so it sucks air and agitates the water, a brushog barely in the water, etc, all will help. Just pay close attention to the machine so you don't overheat it.

How big is the pond (surface size and maximum depth), and how much did you add?