Quick question, what is the best position for an external filters intake tube? I have a deep tank and the current intake tube is about 3/4 down, I was thinking of extending so its just above the sand ( not close enough to suck up sand mind)
Depending on the substrate media, an intake tube can be as close as 2 inches from the media. I would suggest keeping the intake tube a little higher than 2 inches to prevent uptake of tiny stone and silicates from sand as they may damage the impeller. In my 24 inch deep tank the intake tube is 6 inches above the gravel and floramax substrate and I have not had any issues with substrate material being sucked into the filter.