I have been reading a lot about the problem between having a HOB
filter and sand substrate.
Well I have two, and I believe this is the reason for my noisy filters. I am guessing that the sand probably had infiltrated both my filters, my kribensis love to suck and spit out sand so I am not surprised.
Doing more reading, I read that having a pre filter would greatly help reduce the sand from getting into my impeller.
The problem is, I have an emperor 400 and a penguin 150 both which have a weird shaped intake. Where can I find a customized pre-filter to cover up the intake?