acrylic piece needs cut

[smoothie7]

I have a 90 gallon tank with an overflow of 4 1/2" square. I would like to cover that up with something to minimize the noise. I have a piece of 1/4" acrylic that I could cut to make fit. What do you recommend me cut it with so it doesn't chip or crack with no rough edges? Thanks.

[Wall_Tank]

Table saw.  It should not chip with a good blade, but will need sanded a bit to cleanup the edge.

[Blazinreef]

Or nice and slow with a good jigsaw.

[andys1982]

Be careful covering.  From time to time the teeth on my overflow will clog to the point that it actually spills over the top.  If I had it covered there'd be a serious flooding concern.  To minimize the noise in mine I added an extra length of tubing to the stand pipe.  This raises the water level in the overflow reducing the distance of the spill.

[Viggen]

is the noise from the water falling into the oveflow box where the water level inside the box is a fot or so lower then the tanks water level??

If thats what the boise is from.... falling into the overflow box just raise the level inside the box.  I made durso stand pipes for my tank which makes it silent

[smoothie7]

the tank is not set up yet. I was just told that I may want to cover the hole for sound reduction.

[andys1982]

If I were you I'd just hang tight on it.  The one I cut did very little for muffling noise.  Plus, there are several methods to setting these up these up to have minimal to no noise generated.  IMHO, the best is the bean animal method (just google it).

[AJ]

Use the "Herbie" overflow plumbing method.  We just did it and we have zero noise coming from our overflow.

[Westeri]

I thought he indicated his overflow box had a 4.5 X 4.5 inch footprint.  I wouldn't think that has enough room for either herbie or bean-animal overflow piping.   I am under the impression the tank has an existing overflow box installed as opposed to he was planning one, in which a change in overflow box size may be possible. 

[andys1982]

I'm pretty sure a bean can be setup on a factory overflow using both drain and return as drains and running the return over the side.  If I was starting my factory build from scratch I'd be giving it a go because the modified bean I've got on my 45g is dead silent.