Pond Boss Forums INTRO Questions & Observations Chocolate to Green

The water in my pond has gone from muddy chocolate to grass green in the last 3 days!!What's happening??? Will this kill my fish??? Is it an aeration problem? I do have a fountain in the pond, and my new aeration system is on it's way.

Congratulations, you have an algal bloom.

That's a good thing, as long as it's not too intense. How thick is it - at what depth does your hand, a white object, or (better yet) a Secchi disk disappear? 12" to 18" is usually considered optimum. Less than 12", we worry about an oxygen crash resulting (when the bloom dies or when cloudy, windless days occur).

For info on measuring clarity with a secchi disk, see here.

That's a relief!! I thought something was going wrong. I don't have a secchi disc, but I will make one today and check the clarity. I am sure I will not be able to see down to 12 inches. I have a submersible pump with a fountain head that I thought was all I needed for aeration, until I started reading this forum. I have ordered an economy air station from Forever Green and it is being shipped today. Hopefully that will take care of any oxygen depletion. Will the pond remain green? I will post again tomorrow and let you know what the secchi disc results are. The days have been very hot here in southeast La. with a fair amount of rain. How long do you think I have to get the aeration system installed before before I face an oxygen crash?

Good news ....bad news. I had a DO crash(bloom died) last summer with a 24/7 bottom aeration system running at the time. Sometimes you just feel real helpless. Good news, I only lost about 20 bass and maybe 30 CNBG. Just 5 of the bass were above 14" so it did some pond management cleansing for me all in all. I have since installed a horizontal aeration system in addition to what I had for emergency backup.

I dropped my homemade Secchi Disc into the pond yesterday and at best I could see it at 8 inches, but that's about all I could see before the water changed color. The water has changed color again. It's kind of an olive green now instead of the grass green it was the day before.

That change reflects the plankton community now having more zooplankton (brown/green) in the mix along with the phytoplankton (green).