The truth about algea and windows

The myth is that sunlight alone will cause an algae bloom in an aquarium. The truth is that an excess of sunlight, nutrients and CO2 will cause an algae bloom in any tank. Control these factors, and you won't have problems. Easiest way I've found is to plant the tank--then the plants soak up both the sunlight and extra nutrients, and CO2 becomes the limiting factor.

alga

hi,
there are some fish that will eat a lot of algae.
Basic plant biology can give an understanding of algal growth.
H2O + CO2 (-->photosythesis-->) = CH2O.
By controlling these paremeters you can master the algae.
but if the tank is by a window and you have long sunny days, you can expect a battle with the algae.
A suggestion is to stock the tank with a colony of algal grazing cichlids.

Which way does the window face?

Do your blinds permit direct sunlight into the room in summer? Doesn't that fade the chintz?

I don't understand this problem with sunlight! Do people let direct sun in, but just pump the old airconditioner to make up for it? Doesn't everyone control sunlight indoors?

I found last summer that some direct sunlight on a planted tank resulted in good plant growth, crystal clear water, and a little extra green on the glass.

A couple of hours of morning sun will make your tetras spawn...

My planted 40 gets 2-3 hours of sunlight each morning, more in the summer. I've never even worried about it. The only noticable result is that a the plants on one end of the tank face east a bit.

The famous/infamous Diana Waldstad uses nothing but natural light for her tanks.

Natural light can certainly be used, but it is not as easy as timed, controlled, uniform day-to-day artificial light. Stability counts - in water parameters and in lighting. That is hard with natural light.