my fluval 306 is making occasional popping sound
Recently my Fluval 306 has started making an occasional slight popping sound, it makes the sound every couple of minutes, so ten's of minutes. I took it apart, cleaned it and it is still making the noise. Changing the flow rate doesn't appear to have any effect. it has been in operation about four months.
I did a google search, and the only thing which seems consistent is air trapped in it. How would air get in and how would I get rid of it, if that is indeed the cause?
40g breeder with 4 Tequila Sunrise Guppy, 4 cory cats, 13 neon tetra's, 1 dwarf Gourami, planted with anubius and java fern, 36" 4-bulb Current Nova Extreme. 10g with a beautiful blue Crowntail Betta with blasting sand substrate. Also two cats who keep an eye on the tanks while licking their lips.