Pond Boss Forums GENERAL QUESTIONS Water chemistry Algae?? And now comes the FISH KILL....

Over the last week or so my pond is starting to develop a heavy algae bloom. But it is something I don't think I have ever seen before.

The first 2 pics were taking yesterday and the last one about an hour ago.

Is this normal?

Holy moly...that is a bloom! Does that plankton in the third pic look blue-ish? I am no algae expert, not even a novice, but surely hope it's not toxic blue-green algae. Need some help from the forum experts.

I'm right there with ya schmidt...my big pond is probably 40% covered, and 90% of the growth has happened in the last week or so. I'm in the middle of devising a scoop to mount on the front of the pontoon boat to see about removing a bunch of it.

It apperas that the thick stuff is wind driven to the downwind side of the pond. Is that correct?

It is a plankton bloom and dense. What is the visibility of the water in the upwind portion of the pond?

In the 3rd pic there are blue chunks floating in the mix of it all. From what I have read blue-green algae will not clump together, but I may be mistaken.

That skoop idea might not be a bad plan...

ewest, you are correct. It is concentrated on the downwind side of the pond. The upwind side had a visibilty of at least a foot or so last night, which is GREAT for my pond.

I would keep an eye on visibility. You can easily break up the thick areas with a little water movement.

Anything I need to worry about? Should I try to get what I can out of the water?

The algae is feeding on the nutrients in the pond. Once it dies and decays, the nutrients are recycled. By raking out the algae and getting it out of the pond basin, you'll be removing the nutrients from the pond, helping to break the cycle of bloom, die, decay. As it decays it uses O2.

IMO it is always a preferred option to manually remove unwanted plants for just the reason esshup mentions. Often it is not practical due to the effort required. It can be next to impossible to remove plankton. Often but not always the plankton you see on top and wind driven like you pictured is soon to be dead. It can't hurt to scoop it out and put it on the bank. I am talking about phyto/zooplankton not thick blue/green algae (cyanobacteria). I would scoop that out if possible without a lot of effort.

Do you think that this is cyanobacteria? Or just plankton? Is there any way to tell without sending off a sample? Thanks!

My guess is you have some of both. Looks like mostly planktonic with some bluegreens (cyano). Bill could give a much better guess.

Bright bluegreen patches are dying bluegreens - a common symptom of some of the decaying Cyanobacteria. My guess is a lot of the other film is also Cyanobacteria.

That's lovely! Is there anything I can do about it? How harmful is this stuff? I know the department of health around here makes it sound like a serious plague. My cats have been drinking out of it during this time and they haven't keeled over yet.

I have about 40-50 fish in traps right now, should I clean them now, wait till the bloom is gone, or just trash them?

Also, what are some ways to prevent it in the future?

Thanks for all the help, not sure what I would be doing without the help of POND BOSS!

How is your visibility now? If it stays the same or gets better (greater than 12 in) I would just keep an eye on things. If you have a boat you could go out with a paddle and break it up (much will disperse and sink). Any type of water movement would help. I don't view what you have as a serious problem as long as the visibility is 12 in or more and getting better (18 to 24 is better).

Do you know your alkalinity?

My visibility is still around the 10" - 12" mark. That is the best it has ever been since I purchased the property back in February. I do have a 3 person pontoon I can get out there with and stir some things up.

I can check the alkalinity tonight after work and get back to you on that.

I would not be overly concerned about any toxic effects from this algae. Even if it is cyanobacteria, only a few specie emit toxins. You would have already noticed any harmful effects i.e. dead fish (or in your case dead cats). Remediate as with any other algae bloom.

Wind picked up today and the bloom is mostly gone. A lot of green flake looking pieces suspended in the water now though. Did a water test and came up with the below:

Total hardness: 100
PH: 8.4
Total alkalinity: 120
Cyanuric acid: 100
Chlorine and bromine all 0's

That water looks good to me. Keep an eye on things an as long as the visibility is increasing you should be ok.

So what if the visibility goes south? Got home today and the wind blown side still has a film and some built up algae on it. Rest of pond surface is clear but visibility is down to about 3" and looks pretty green.

I read back through this thread and could find no mention of possible run-off. What has been the rainfall situation at your location? Is any on the land adjacent to or near the pond used for agriculture or livestock. This could be the source of your evident high nutrient load. In order to find out how high, you will need to test for Nitrate and Phosphorus. How much aquatic vegetative coverage do you have?

This pond is in my back yard. We don't use anything on our lawn and do not have any ag land up to it. I also have no aquatic vegetation in the pond. I am assuming that this is the negative result from using alfalfa bales to clear the water as my neighbors pond has 0 visibility but no algae problems. The two ponds are separated by about 20' or so.

And for the rainfall... What is that like? Predicting worst draught since the dust bowl in 1930 for our area...

Organics decaying add nutrients to the water. Either FA, Phytoplankton or vascular plants will utilize the nutrients. You might want to aerate if you are not doing so now, because if the Phytoplankton has a sudden die off, O2 will crash and fish will die. All that algae will cause O2 levels to get low by first light too....

Lower water levels are concentrating the nutrients into smaller volumes of water too.

Without vegetation to use up the nutrients, you WILL have algae.
I thought that you were in drought conditions, but wanted to be sure. Really a bad situation, 61% of the lower 48 in some level of drought.

I don't have an aeration setup nor know where to even begin with that process. Everything I have read on that sounds pretty expensive to get setup properly.

Will there be any sings leading up to a fish kill or will it happen all at once? For instance, will fish stop coming to feed, start looking unhealthy, etc?

What type of vegatation would help limit algae in the future? This drought is crazy, I thought we were better off than last year but it doesn't sound that way. I think there will be a well project in my future before next spring.

When you notice signs it's probably too late.. Fish will be piping at the surface trying to get air.. You will either notice real little fish around your edges or as in my case all the big fish died first because they need air the most.. No problems since aeration..