String Algae on Plants - harmful to them?

[Mmathis]

When your submerged plants are covered with string algae, is it harmful to the plants?

I constantly pull the submerged plants out and pull the stringy stuff off [and some are really almost smothered by it]. Also, what about the stems & roots of the floaters like Parrots Feather?

But was wondering if the plants would be OK if I did nothing.

 

[crsublette]

If the density of the algae on the plant's leaves is too great, then the algae will be an obstruction to the plant's survival.

Now, if the algae is on the plant's roots and stems, then it could be having a symbiotic relationship with the plant. However, in the context of particular species of string algae, then these species are self sustaining and are just on the plant as a parasite to serve the alga's own requirements of survival.


Parrot Feather and fully submerged aquatic plants was a pain for me to keep since string algae would sink the plant and the algae growing on the plant's leaves. It was constant maintenance.

For the brown dust algae on the leaves, I just gentled ruffled the plant leaves underwater to know off the algae, but this only worked for particular types of algae. For other types of algae, I tried using a pond vac and essentially sucked up the plant's stems carefully so they would not detach from the plant. This took much of the algae, but it would also take some of the leaves. The plant did not grow new leaves fast enough so I had to give up on this idea.

Eventually, I did a hydrogen peroxide dip in a 5 gallon bucket. I put 1 ounce of the basic 3% food grade hydrogen peroxide from the grocery store in a bucket filled around 3/4 way up. I anchored the plant so to be fully submerged for about 12 hours or once the algae easily disconnects from the plant or starts floating in the water. Depending on the volume of algae on the plant, I would have to increase the hydrogen peroxide dosage. Quickly rinse the plant with some pond water in another bucket. This is all I did. Eventually, it became too much maintenance for me to do since I had alot of plants to do, but it worked.

I have had alot of Parrot Feather smother and die on me. I eventually had to put it will above the water line, in a styrofoam types of plant floater, but I didn't like how it looked.

You might could try a floating plant ring, that is quite shallow so to prevent the entire plant from being submerged.

 

[Mmathis]

Wow, Charles! This is just that old stringy stuff. So basically, I should keep pulling the stuff off when I find it. Sometimes I find there's just a little bit, but sometimes the plant (submerged kind) will literally be encased in it.

 

[crsublette]

Yeah, that is what was on mine. Also, I have had the basic string algae variety choke the plant as well.

I also had stuff that looks like dead algae, but I think it is actually a growing algae, that is some type of brown string algae and falls apart like dust kind of and very easy to pull of.

 

[crsublette]

There are many different types of string algae and all of them are not the commonly invasive, troublesome, cyanobacteria variety.

Look into the possibly buying the book, even though it is quite technical, which there is an e-book version of it, called Ecology of the Plant Aquarium. Although many plants in the book will apply to an aquarium context, there are also references to many plants that apply to our pond context. It talks about how to use plants and which plants to use to emit toxins and consume nutrients to help control your algae issue, which it seems to work quite well for callingcolleen1. All plants have self defense toxins, commonly referred to as allelopathic chemicals, and these toxins are emitted into the pond water so to change the environment and make the environment less conducive for other plants to thrive. All plants emit different types of toxins that impact different types of other plants. The toxins are quite selective as to what they target.

I believe this is exactly why callingcolleen highly recommends sedges, rush, and sweet flag, which these are from the acorus gramineus family. This plant family and also the Pistia Striotest family (i.e., water lettuce) is are known to excrete a chemical called, Asarone, from the plants roots acting as a selective microbicide, that is it only kills bacteria types of plant bacteria such as the bacteria that helps to create particular types of string algae.

Water changes impacts the effectiveness of this type of approach to try to reduce the algae.

Just something to think about.