Black tar on UG/HC Cuba, is it red algae? ID please.

[Flyinghellfish]

Greetings fellas,

I have this weird black tar on my HC Cuba and UG, it kind of resembles a black smug on the plants.

Stats:
6 gallon
EI dose [NPK dry dose] + Flourish + Flourish Iron
25% twice weekly water changes
42 LEDs 7000k (This is not very bright, don't be fool by the 42)
CFL 6500k Desktop Lamp

Photo Period: 10 hours
Co2 pressured : 1 bps

[Flyinghellfish]

bump, anyone?

[Biollante]

Hi,

Almost certainly, red alga, Rhodophyta, probably genus Audouinella, really doesn’t tell you anything useful, par for the course with my answers.

As you are probably already realizing the “black tar” is a particularly nasty member of a very nasty family. Perhaps the worst feature being it does very well in water we consider good quality with good circulation.

I should wait for Tom Barr, but I may as well say it, CO₂. Work on raising the amount and stability of CO₂ in solution. The “bubbles-per-second” measurement is almost meaningless.

Whether this is a “black tar” variety as you might find in swimming pools or a developmental stage of a more common Black Brush (or Beard) algae, it is doubtful you can remove the algae from any infected plants.

Even the algae on the rocks are difficult to remove as the algae form protective layers so that even bleach is not particularly effective.

Biollante

[Flyinghellfish]

Hahahah at your title, she already thinks I have a obsession with my new hobby. What doesn't help is the various things I brought home - Syringe for spot treatment, Dry white powder I brought from a hydroponic store, digital scale, and a new set of measuring spoons.

No one seems to have experience with this type of algae and yes, I already up my Co2. It's a 6 gallon tank with a glass top (Fluval Edge) and my 4dhk solution is yellow-greenish, far from low levels of Co2. I also have the Aquaclear 20 HOB on full blast, the amount of water it turns over is massive for a 6 gallon. There is very little Co2 out gassing as I full the tank water up.