I need to have aquarium drilled…..need advice


I have a 200 gallon bowfront aquarium that will have African Cichlids in it. I would like a sump and need to have the aquarium drilled. I have a guy experienced in cutting glass that can do it but I need to know where to drill and how big the holes need to be. Any advice is appreciated. Thanks in advance.


I'm not a sump expert, but have seen the overflow & inflows positioned near the back of the tank in opposing corners.
A sump system is probably the best form of filtration, but before committing, be sure to research XL canister filters. An FX 6 could easily handle a 200 gal. tank.
I've read many threads about people wanting to reseal drilled holes in big used tanks. Sump systems aren't for everyone.


This is the layout for my new CustomAquariums custom tank build. The siphon stoppers are the returns. You might want to check out there site. They have a really nice (not cheap) sump, overflow and return system. I like that the sump is made of HDPE and is virtually unbreakable. If you're not using there system you might want to spread the overflows a bit more.


Typically, large tanks are produced from tempered glass. Drilling holes in tempered glass is quite different than drilling a hole in plate glass or float glass. Tempered glass has built-in stresses that give it strength. When you drill into it, it changes the stress pattern and the glass can break. If your glass guy has experience in drilling tempered glass, then he might be able to do it successfully, but otherwise, he might destroy your tank.

If you do decide to take the risk, you need to purchase your bulkhead fittings first and then drill the holes based on the diameter of the fittings. The size and number of the bulkhead fittings will depend upon the size of the return pump you plan to use with the sump. For a 200 gallon aquarium, you will need a pump rated at about 1800 gph flow rate such as the Danner Mag Drive Supreme 18.

There are two other options. One is to use an overflow box. Here is a video that shows how they work. With a 200 gallon tank, you will need two large overflow boxes, one at each end of the tank.

The other option is to use a canister filter as has already been suggested.

While sumps are highly recommended for saltwater aquariums because the provide space for trickle/shower filters, protein skimmers, etc. they are not necessary for freshwater aquariums. A combination of HOB filters and canister filters can get the job done quite nicely. Remember that with sump systems, if they are not designed properly, a power failure can cause the sump to overflow. Unfortunately, I have had to mop water from the basement floor on a few occasions.


Good point R makes about the tempered glass, risky. My glass is either not tempered or was drilled first then tempered. I've had both internal and external overflow boxes on my salt tanks. not a fan of the hang on the back type. Internal work great and are drilled through the bottom but take up a lot of tank space. My new CA 180 is a freshwater set up and like R says sump probably not necessary for filtration but I like it because I can put my heaters (some canisters hold heaters) and pump and it adds about 40 gals of volume to the system and I figure a little extra filtration can't be a bad thing. So far it's working great and think it will allow me to stock the tank a bit more. The CA overflow system takes up almost no space at all and the siphon stoppers eliminate the possibility of back-siphoning and overflow. Very easy to service!

Maybe just the bottom of your tank is tempered?


You need to know what kind of overflow you prefer to know where to drill.
You can tell tempered glass by looking with polarized glasses ..
You can not drill tempered .
Most bottoms on tanks less then 10 years old that large are Tempered so then you need to look at
the back and consider an overflow like the Bean Animal /or an Eshopps eclipse ..


have you thought about diy pvc overflow system w/o drilling?

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