Skimmer low bubble production

[dsmhero]

I have a CPR BakPak HOB skimmer that has great bubble production with the upgraded pump but the last few days the bubble production has been very low. It is a venturi style skimmer and the water level is consistent.

24g tank with a pair of clowns and a carpenter wrasse.
Nitrates - 0
Phos - 0

I am curious as to why it is barely producing bubbles. Any help would be wonderful, thank you in advance!

 

[dsmhero]

Problem solved, snail guard was plugged up. I didn't think it would take less than a month for that but oh well.