QUOTE(AZ bonsai @ Oct 30 2013, 08:39 AM)
I did jet spray tap water to the trunk, but it started to have algae.
Is there any chemical to remove the algae?
A couple of things to do. You can paint with the following(use art paint brush, not toothbrush):
1) Fungicide mix with water.
2) Clorox (very diluted) mix with water - this one be careful...
Brush, let it dry, then wash off.
Be careful that the chemical do not drip on the soil or else, roots may die. Be careful as well when you wash it off. I usually cover the soil with a layer of plastic bag before I paint or wash.
I find H2O2 quite effective to kill pest but not sure about algae/fungus.
But one thing ya, the algae is there because its wet. So after you clean, if the wetness still persist, it will come back.
cj
This post has been edited by cjloong: Oct 30 2013, 01:23 PM