Not a single stream of bubbles appearing for my ferns! Added iron

fertilizers, CO2 and a 7000K light but still no bubbles! WHY?

How much lighting over how many gallons and what kind of plants?

Just because you don't see any bubbles doesn't mean they aren't photosynthesising. It generally takes a lot of light (3+ wpg), CO2 and the right kind of plants to actually see "pearling" which is bubbles forming on the leaves because they are producing so much oxygen. Its a very good thing, but not something you'll see very often in lower light setups.

A lot of people see bubbles on their plants when they do a water change and think 'oh look, they are pearling' but this is just a result of the oxygen getting mixed up in the water when you refill and "trapped" against the leaves, not true pearling.

And also, those strings of bubbles you'll see rising, that generally only happens when a plant has been damaged. So you may have seen them before because you broke a leaf or something...

I have around 4 watts per gallon in my goldie tank and the only thing I've even seen pearl there was some green algae.

The only time I've seen pearling is in the tropical tanks that were getting direct sunlight from a south window. The najas grass was pearling up a storm with no added ferts or CO2.

I have 40 watts on my 33g tank with a diy CO2 set-up. Somedays my plants pearl and somedays they don't! I think they only pearl when the water can not hold any more oxygen.

Be careful, plants are addictive!

Anita