[cS]

By "thread algae", I mean these long filamentous green strands seen in this photo. Apologies to IUnknown for the flashback.

At least with this algae, I am fairly confident that NH4 does not play a major role because I have it seen it in perfectly healthy tanks as well as heavily planted new tanks. Instead, I have seen a correlation between over-dosing traces and the occurrence of this algae a few days afterwards. Which trace element? I have no idea. I have Iron Chelate powder that I can use to test if it's excess Fe, but the scientist in me is on vacation. Perhaps someone more daring would partake this endeavor.

My most recent outbreak is in a newly set-up, heavily planted, high light 10G. On day 3 of setup, I dosed 1/32 tsp Plantex CSM+B (0.23 ppm Fe). On day 4, I noticed short hairs on leaves. By day 6, 75% of the tank is covered with these long green threads. :evil:

In my mature high light tank with healthy plant growths, I will also get this progression of short hairs --> long green threads when I dose micronutrients in excess. So now, if I see signs of the short hairs, I cut back on dosing micronutrients.

Coincidence? Paranoia? I would appreciate feedback.

 

[pineapple]

Coincidental timing perhaps. In the last two weeks, I managed to acquire thread algae in a 30 US gallon aquarium which was doing very well otherwise and is heavily planted. CO2 level is consistent and high, plants pearling. Water clear. Tank maintained well. Dosed with KNO3 and PO4 (Fleet solution). The only change I made just prior to the onset of thread algae was the addition of Tropica Master Grow (TMG). Initially, I added 3ml per week and then increased the level to 3ml twice a week. The increase to twice a week dosing coincided with the appearance of thread algae. Under the higher TMG dosage, thread algae was nice and healthy, proliferating. As I decreased the TMG dosing, the thread algae has been looking less well, finer threads and fewer of them. (I am also adding Flourish Excel at the rate of 10ml a day which may also help in the demise of the thread algae). I should add that NYC water is very soft with little or no carbonate hardness.

On one hand, the TMG dosing gave some excellent results with Rotala sp., in terms of leaf quality and colour. On the other hand, thread algae is not something I wish to see in the aquarium. Perhaps I should develop a new aqua-style, akin to Tony Gomez's 'Algaescape' in which he came to appreciate the art of algae.

Andrew Cribb