Too many clones??

This is my first grow. I grew one northern lights plant for about 2 months and was in perfect health. I took about 20 clones off her. I grew out 12 of the clones and I am at the end of flowering and they didnt produce much bud. The bud sites are pretty small. My question is did i take too many clones off one plant? Is that the reason they didnt produce much bud? Or is this common for NL?

I don't think its the clones fault you didn't get much bud. Probably either your experience, or your equip.

I have a hydroponic ebb and grow system and a 600 watt hps light with a vented hood and the cool air intake or whatever to keep it cool. I know i lack experience but I have read alot. I am really unimpressed and a little discouraged by the way the buds look. The plants have no damage, just underdeveloped budsites. The ppm and ph has always been right and I have bumped my nutes up when I was supposed to. Just trying to find the mistake so I can learn and prevent it. I'll try to post pics tomorrow.

In answer to your original question.......You can take as many clones off a mother plant as you want. It doesn't effect the clones. The mother maybe stressed if you take too many, but given time she will recover. I have taken enough clones off a small mother to have to put her out of her misery and use one of the clones as a future mother. I don't know about NL yield. Sometimes if you make any mistakes with PH or PPM ratios the plant yield can be effected dramadicly On the other hand your mother may have been just a low producer. Too many variables for an exact answer. Pictures would help, but may not lead to an answer.

NL yields decently. We'd need to see pic to conclude if your cuttings cause a low yield.