>> 4 40w tubes (2 Aquasun, 2 gro-lux bulbs, 3 weeks old)
-bulbs are on for 10 hours a day DIY wet dry #2 substrate with potting soil
My water is hard and has a high pH. I am also adding a CO2 system next week.
Will this help? <<
The basic problem is that your tank is out of balance. With the amount of
light you have, your plants need a fair amount of CO2. With a high pH and
hard water, (probably high KH as well) you have very little CO2 available in
your tank. Your plants do not benefit in an increase in one area if their
other needs are not met at the same time. The thing in shortest supply
becomes the limiting factor.
Any time there is an imbalance in a tank, algae can take over. The algae may
or may not have been introduced from an outside source. In my experience, if
you introduce algae to a tank where conditions are not suitable to its growth,
it dies off. Conversely, since there are algae spores in tap water and even
in the air, given conditions to its liking, algae can appear "out of no
CO2 can certainly help to balance the lighting you are using, but you will
probably also need to supplement trace elements.
I and many other people have found that soil or peat enriched substrates
don't always work well in a high light tank. These substances release organic
material into the water that can encourage algae growth. My personal
preference for a substrate additive is laterite.
Finally, you might want to check your phosphate and nitrate levels both in
the tank and in your tap water, since an elevated amount of either
macro-nutrient can lead to algae problems.
E-mail from: Karen Randall, 12-Apr-1995