This Red/Brown Stuff Keeps Coming Back....

[Dutchman0222]

We continue to have issues with this reddish brown algae? on the waterfall rocks and slowly around the liner.
We had some high nitrite levels and did two 50% water changes last week three days apart.

Not sure what is causing it.

 

[Mmathis]

How old is your pond? Do you have fish or plants?

 

[Dutchman0222]

Pond is roughly 5 weeks old. Yes to plants and fish.

 

[AlyssaFish]

Brown algae is a type of cyanobacteria and is not actually algae at all. It tends to out-compete green (actual) algae in environments that have less direct sunlight. It feeds off nitrates and phosphates just like green algae.

Best way to get rid of it is to finish cycling your new pond and add more plants.

 

[Dutchman0222]

We do have some plants already

 

[AlyssaFish]

I know, I read that. But more is always recommended with an algae/cyanobacteria problem--or reducing the bioload (removing fish).

 

[Dutchman0222]

Fair enough, we will see about getting some more.
You are correct about it not getting direct sunlight, gets about 2-3 hours in the morning and then shade from there on in.

 

[Mmathis]

@Dutchman0222 As I was Googling this, I ran across this thread from GPF (it’s us: Garden Pond Forum!) from about 8 years ago. It’s an oldie but a goodie!

Brown Slimy Algae?

Hello, Ive noticed a brown algae in my pond. it started about two months ago with loads of tiny bubbles appearing all over my rocks and pond wall, the bubbles then changed into lots of bigger bubbles that covers all the rocks, over the exposed areas and the pond walls and now i still have the...

www.gardenpondforum.com

 

[IPA]

First, if you had high nitrites than your pond is not completed the cycle. What you are seeing is just all part of the process and it will take a good long time before you can consider your pond established. Once the cycle completes and the nitrifying bacteria start producing nitrate you’ll notice more green algae and you’ll probably get string algae. Plants plants and plants and a lot of patience.

 

[Lisak1]

I'd recommend you stop with the water changes - you're setting your pond back to "start" every time you do that, especially at 50%. Let your pond mature and see where it takes you. Most pond "problems" aren't really problems at all quite honestly, especially when they involve algae.

I think that looks like pretty normal algae starting on your rocks by the way - maybe a bit slimy? You'll find as your pond matures, the algae will change over time. And you should expect and welcome algae growth - all healthy ponds have algae.