Overflow flushing after 8 years

[AnthonyAce]

My tank has been established for awhile with no overflow 'flushing' sounds but lately every once in a while I get the flushing sound 2-3 times and than it stops. I know from researching threads I will need to drill holes in the top of the cap but i was wondering why the sudden change? :scratchch

 

[nanoreefer22]

Can we get a pic of your current setup?

 

[masterswimmer]

Possible algal buildup inside the pvc/tubing reducing the overall diameter and thereby affecting the flow. Just a theory.

Russ

 

[AnthonyAce]

overflow

I thought about the algae build up but its a 1 1/2" return what gets me is that it only happens occasionally

 

[JimmyR1rider]

Maybe your return pump is starting to go and the flow rate is differing slightly sometimes?

 

[nanoreefer22]

Clean out the hole at the top of the cap. It's possible there is salt build up or something blocking it from the inside. If it's even a little more closed that it needs to be, the drain won't get enough air and it will do the flushing thing you're talking about.

If you want to test it just cover the hole with your finger and you'll see it happen.

 

[garys reef]

+1 i clean mine all the time calcium/ salt build up