Drilling holes in an acrylic aquarium without removing contents

[luilui]

I have a 1.5 year old 75 gallon acrylic reef tank that currently has 2 Hagen canister filters for circulation, but want to add a sump. I'm planning on using an eShopps overflow into a Fuji Cube sump. I will lower the water level about 1/3 and drill through the 1/2 inch acrylic with a hole saw. does anyone see a problem with my plan? I don't want to tear down the tank, as my corals are doing great, and I don't want to disturb them. Of course I could use a siphon box, but would prefer to use an overflow box for overflow safety.

 

[VintageReefer]

I would use painters mask - the kind with masking tape and pull out plastic drop cloth - and put that below the intended spot for the hole to catch any plastic shavings. The shavings might float and be easy to remove with a net but I’d be worried a fish might eat it

 

[Doctorgori]

only a couple of issues I can see
Vibration , also there is a ideal cutting speed with plastic due to melting
hopefully some acrylic folks can chime in and explain their technique

 

[NCcoastalreefer]

I've drilled my 75 acrylic while filled. Mark where you want it, double check location and that it's not too close to any seams, it's best to have someone hold a vacuum on the inside of the tank at the spot of the cut so that you catch any acrylic shavings before they make it into the water. Don't go too fast and keep the bit cool by dipping it in a separate bowl of water to keep it from melting the acrylic as it cuts

 

[magallonbuckinbulls]

Use and acrylic hole saw. You want to run at a lower speed, so you don't melt acrylic and get your teeth all gummed up. If you never drilled acrylic. I would get a pc of acrylic and practice. Also, you'll need to create a suction as motioned above. I've made my own with seal. If drilling under water, make sure you place the other half of the bulkhead in the suction vessel.

good luck

 

[luilui]

Thanks everyone for your suggestions. I've drilled plenty of acrylic panels over the years, just not an aquarium still filled with water!

 

[victorcan]

Anyone have avideo of the process? being forced to drill a 3/4" bottom to rid silicone from a previous owners attempt to fix a leaking bulkhead now cant get the silicone ring off and cant get a good seal with my bulkhead and make a hebie style overflow system vs the existing durso system. do i have enough room for another 1" return line / hole being that close in between the drain holes?