I bought a hiblow 200 and a quad Malala diffuser 9” disc setup and have it ran 100’ on a 1/2” self weighted line with a check valve. Two discs are moving nicely and the other two have maybe 1/4 of the disc making bubbles. Is the pump too weak for the 4 diffusers? They are in 6’ of water.

Would a larger ID airline help or removing the check valve? Any insight or opinions would be appreciated.

Thank you

HP Series Air Pump 200
Max Pond Size - 2 Acres
Max. Water Depth - 10'
Max Air Flow (lpm/cfm)- 200/8.4
Max Continuous Operating Pressure (kPa/psi) - 30/4.3

Dual Air Diffuser and Dual Base Kit
Air Volume - 5.6 - 16.8 CFM
Platform - 2
Diffusers - 4
Dimensions (L x W x H) - 23" x 22" x 10"