Floating Algae

[toups]

Very similiar to this older thread:
https://www.gardenpondforum.com/threads/floating-scum-all-summer.20296/
I'm having a lot of floating algae.

My pond is about 8'x12' and ~3 deep on average so somewhere in the land of 2000 gallons. I didn't have this issue in past years.. but my pond is pretty much in full sunlight which I know contributes a lot to algae growth.

I have a basic floating skimmer that I use for catching any leaves, I can empty it and clean it twice and day and still not keep up with the algae.

Same pump/filter as before - pumps rated for 4000 gallons so it should be enough water flow.. filter has 22W (I believe) UV in it.

I'm wondering if it's because my plants are just beginning to grow vs previous years. It was in the 40s up until a couple weeks ago and now it's 95 today! My plants are well behind but the algae just isn't stopped. General plants I have growing are: Lilly pads, water hyacinth (floating), a couple submerged plants like hornwort, and some grasses along the side,

Only other change from previous years would be the fish - I had only 3 Ogon previous years (around 1.5ft length each) but they spawned about 30 extra going into last fall. Those are all around 2-3 inches now.


Going to go do some water tests right now and will post the results as well.

 

[sissy]

ow old is the uv bulb and how fast is the water flowing through it and is the glass around the uv bulb clean and how often do you feed you fish and how many and do you test the water and temps of the water .

 

[Faebinder]

You got way too many fish if those 3 spawned. 2000 gallons should hold like 8 koi.

 

[toups]

ow old is the uv bulb and how fast is the water flowing through it and is the glass around the uv bulb clean and how often do you feed you fish and how many and do you test the water and temps of the water .

Brand new bulb - came with maintenance kit for the filter - just cleaned the entire thing out 2 weeks ago.
Feed them just once a day.
I tested before I did the filter cleaning, everything was in the "normal" range - doing another test now.

You got way too many fish if those 3 spawned. 2000 gallons should hold like 8 koi.

I'm planning to reduce the number, was waiting for warmer weather to sell them off or find new homes for them.

 

[sissy]

8 small koi but not larger fish .

 

[toups]

Here's the current test results:
Water temp - 78 F
Phosphate - 0.50 ppm
Nitrite - 0.25 ppm
Ammonia - 0.0 ppm
pH - 6.0

 

[Meyer Jordan]

Phosphate is entirely too high. This reading should be no larger than 0.05. Likely a result of feeding too many fish. Algae issues will continue until this Phosphorus level can be substantially reduced. Renewed plant growth may help but it may not be enough.
You do not indicate the Nitrate level.....the other prime nutrient.

 

[toups]

Phosphate is entirely too high. This reading should be no larger than 0.05. Likely a result of feeding too many fish. Algae issues will continue until this Phosphorus level can be substantially reduced. Renewed plant growth may help but it may not be enough.
You do not indicate the Nitrate level.....the other prime nutrient.

0.05? The test I have goes on a scale of 0, 0.25, 0.5, 1.0, 2.0, 5.0, 10.0 for phosphate.

I did just switch my food a few days ago so that could have attributed it to it if you think it's food - I was using floating food and it was getting caught in some areas out of the reach of the fish. New sinking food is eaten up right away.

Don't have a nitrate test at the moment, I'll get one and report back.

Thanks

 

[Meyer Jordan]

 

[CometKeith]

I have seen algae come and go this year. I think the cold weather has made it hard for the beneficial bacteria to remain stable. To me algae is not a really bad thing because it is helping control the bad stuff in the pond. It's the 'sympton" not the "cause" of the problems.

 

[Lisak1]

It's the 'sympton" not the "cause" of the problems.

Exactly! So many people who want to "treat" the algae without asking themselves why it's there. It's like people who want to treat a simple fever - which is your body's way of dealing with the issue without any intervention from you at all! It's the symptom... not the problem.

 

[toups]

I have seen algae come and go this year. I think the cold weather has made it hard for the beneficial bacteria to remain stable. To me algae is not a really bad thing because it is helping control the bad stuff in the pond. It's the 'sympton" not the "cause" of the problems.

Understood!

So here's the things I'm doing, thanks for the feedback everyone:

• Should be getting Nitrate test in today or tomorrow to check that out
• Reduce my number of fish (I really only wanted my 3 main Ogon + maybe 1-2 more total so I'm planning to get rid of all of the new spawns - there any fish birth control? haha)
• I'm thinking of creating a bog filter, made a thread with my idea there: https://www.gardenpondforum.com/threads/bog-tips.21347/
• Will monitor the algae, have been netting the algae on top as people said and I removed the foam filter from the small floating skimmer I have, it's pushing out a lot of aeration bubbles and agitating the surface more... as well as collecting a lot more of the algae since the filter isn't getting clogged with it

 

[CometKeith]

Hmmm... My strategy is to never net the algae because it's important for it to consume ammonia etc that would otherwise be harmful to your fish. Once beneficial bacteria (bb) is present in your biofilter in sufficient quantities then the algae will dissapear on it's own. If your filter can't provide enough bb to do this then you need a larger filter or need to reduce the bio-load in your pond. See below a link to Blue Ridge Farms who are respected breeders of Koi and goldfish in Florida to see typical breeding ponds used in the industry. Notice in the pictures most of their ponds are deep green from algae. Even though it is not attractive, algae in your pond does not hurt anything and conversely it is good for your fish. It consumes waste product from your fish, provdes a rich food for the fish to eat, and provides camoufloge which reduces stress in your fish.
https://blueridgekoi.com/our-company/our-farms/