Algae on floating plants

[jflng]

For the past couple months I have been dealing with an algae buildup on my Salvinia. It's brown, somewhat stringy, and soft. I'm pretty sure it's a type of Diatom. I can include pics later if necessary.

It only seems to be affecting the root system of the Salvina. I haven't noticed it anywhere else in the tank. My parameters are fine. CO2 is pumping the same as always. Dosing is the same. Flow is good...

Any ideas?

[jflng]

I just cleaned out the tank completely. It's spotless and all the plants look great, but I still have this crap growing on the Salvinia. any ideas?

[jflng]

Anybody?

[jaidexl]

Sounds odd, never seen it. Is there flow across the surface? That may be slowly killing the salvinia and making way for this junk. Perhaps it's just a buildup of protein scum caught in the roots. Tom Barr might be familiar with it. It's not uncommon to have some type of thread algae growing in thick floaters but I've never seen brown or soft (unless it's dying, I suppose).

Sorry for not being much help, just trying to get you some attention.

[jflng]

Any advice or bumps help. Thanks jaidexl.

There is a slight surface flow. The Salvinia reproduces like nothing else. I toss out handfulls almost weekly. The funk doesn't seem to bother the plant at all, but it sure bothers my eyes.

A protein buildup could be at least part of the problem I guess. This stuff is threadlike though. It's similar to a hair algae, but all brown like diatoms. I don't think I was correct labeling it diatoms. I really have no clue what it is.

Does Tom respond to the batlight? Can somebody shine that for me please?

I removed most of it last week. It's coming back in force as suspected. I will see if I can post a picture when I get off work tonight.

[jaidexl]

You might get his attention over at barrreport.com, but he's pretty good to respond here as well. He knows a lot of strange algae but I've never heard of this one mentioned. I hope it's nothing like the "grey snot" that's been discussed. Perhaps just some unhealthy thread algae of some sort, maybe collecting scum with the help of the Salvinia roots. I've never really been able to eradicate thread in floaters unless the light is drastically reduced, I usually just remove as much as possible once it builds a good mass, but mine is always like spirogyra, fairly strong and healthy, easy to remove.

Do you dose Excel? Maybe shut off the filters and sprinkle 10mL or so across the surface, not sure how the Salvinia will react.

[jflng]

I can't think of anything that has changed in this tank. The light is the same as it has been for a long time.

I really wanted to avoid using excel because of some of the sensitive plants in the tank. I don't know how the Salvinia would react either. It might work, but I'd rather find a cause so I can get rid of it completely.

Here are some pictures. They might look a little strange because I oversharpened them. They didn't look that great to begin with and I wanted the threads to be visible.

[jaidexl]

Well, I don't know how easy it would be to positively identify without sending it to someone, some type of thread algae for sure, one of the many, maybe Rhizoclonium. I'm almost certain though that it is competing for the nutrients that the roots of the Salvinia are pulling in and possibly leaching. How to get rid of it, I wouldn't know. Rhizo in a general tank setting is usually a sign of imbalance, but since this stuff seems to be acting like a parasite to the Salvinia, your tank specs may all be in order and it may still thrive, unless you find a way to kill it off chemically or by increasing CO2, or simply removing the Salvinia.

If it's a real bother, you have your ferts and CO2 in check, and you want to keep the Salvina, this might work... Grow some Salvinia in another tank or bucket and see if this junk chooses not to grow there. Leave all Salvinia out of this main tank for a while so there is nothing at the surface for this algae to thrive on, then reintroduce the clean Salvinia and hope the algae doesn't reappear. This is what I've done with moss, basically growing it in quarantine until I'm sure there is no sign of algae or other pesky hitchhikers, because trying to battle certain things in the tank where an issue originates is often a losing battle unless you drastically change a driving factor like light.

Another possibility, maybe add some giant duckweed (Spirodela polyrrhza) or Azolla, in theory it might help outcompete the algae for the nutrients present in the root system. Or for no other reason than the fact that I think Azolla, duckweed and/or Salvinia look great growing amongst each other.

[jflng]

Salvinia leaching nutrients eh? I never thought of that possibility.

I would try your advice and relocate the Salvinia, but I don't really have anywhere else for it.

I can maybe cut back the photoperiod, but I can't limit the wattage with my fixture.

I can increase CO2 levels some, and add more floating plants. I'll do this and see what happens.

Thanks for the assistance, and thanks especially for giving me an excuse to squeeze more plants in this tank.

[jaidexl]

Any time you see brown algae growing on the "water roots" of a stem plant, or see staghorn growing from a hole in a leaf, this is what's happening. The algae is stealing nutrients from the plant. If the plant is damaged, then it is leaching, but in the case of algae on roots, I'm sure there is some relationship going on there where the algae is taking a free ride, so to speak, the roots are full of nutrients as they work throughout the day and the algae steals it somehow.

[jflng]

Interesting, I never really thought about it working that way. It makes sense though, since algae seems be more prevalent in certain areas in otherwise healthy tanks.

I upped the CO2 just a little bit today. I'm keeping my eye out for some good deals on nice floating plants. I'll add those as soon as I find them.