How do I tell if my DWC box is getting enough bubbles?

I recently built myself a DWC bubbleponics system. I am using a 35 gallon res for my plants and a secondary 22 gallon res, but I don't think my air pump is going to put out enough bubbles. My Air pump is 3.2 litres, and I have 2 large airstones. They don't put out any big bubbles just a few little ones. My question is how can I tell if I have enough bubbles?

usually a good sign that your getting decent bubbles is
when the bubbles hit the top of the water you can see
little water droplets shooting around above the water
but usually once your roots get into the water you dont
really need to worry how good the bubbles are as long as the
water is aerated

The inside of the res lid, the pots and the medium should be wet. If you think that the airstones are not making it try this. Put a T fitting at the end of the air hose and make a loop, use a pin or small nail and make a few holes in the loop. You can get dohickeys at the pet shop that will hold it to the bottom of the res, suction cups with a little clip for the air hose. It's a pretty cheap solution and it won't clog like an airstone. This isn't my idea but, I can't remember who to give the credit to but, it works. Good luck with the grow.

How much bubble action you need depends on what you want the bubbles to do. If you want them to just oxygenate the water, it doesn't require a lot. But if you want the mist and splash they create to feed seedings until roots are in the water you need more. Read the link below for more info.