Hello all, my main air pump (cheap, bought at Menards) went out today. I am supplementing with a tetra whisper that is doing the job, but I know wont last. Any suggestions for a good quality pump that is less than $100. I am currently running just over 1500 gallons in volume, and would like to keep two stones in the pond itself as well as one in each of my falls (currently building second), and another in my "waterfall reservoir". So a total of five outputs. Also, can I just use regular diffusers/air stones (have 2 2" stones) or will I ned to have bigger ones (like the matala 6 and 9 inch)? As always, thanks for your input and any ideas you may have.