Because a truly gravity fed overflow is the most reliable method to get water to your sump. Continuous siphon overflows that are so common in the hobby and their shortfalls are the reason these overflows were developed. For more information on why, click here.
Yes, anytime you drill anything, even wood, you risk cracking, splitting or chipping. We provide you the tools for a fairly simple do it yourself project, with the knowledge and guidance that has successfully drilled thousands of holes in glass. Of course, these same risks apply to acrylic too, but it drilling acrylic is generally viewed as easier simply because it is a more familiar process (drilling vs. the grinding through glass). You do want to be sure the glass panel you wish to drill is NOT tempered.
Please see this page!
Our overflows use a similar principle as a Durso type standpipe, but it is incorporated into the box itself. This allows the box to have a much smaller footprint in your tank compared to any other gravity fed overflow that implements a method to keep the noise level where it should be (virtually nothing!). More information at this link.
Most the diamond hole saws on the internet are diamond coated bits, a very few are sintered bits. For a DIY aquarium application, a coated saw will drill all the holes you need, well over one dozen (so long as it is cooled and lubricated with plain old H2O, more information here). These bits run about 20 times cheaper than the sintered bits.
A 1" bulkhead uses 1" PVC and fittings, a 1.5" uses 1.5", so on and so forth....same goes for elbows and fittings.
First of all, contrary to popular belief, the box flow is dictated by the bulkhead size, the box has little to do with it. Our Nano and SuperNano use a 1" bulkhead and are rated at 300 GPH. The 700 uses a single 1.5" bulkhead and is rated for 700GPH. The 1500 uses two 1.5" bulkheads and is rated for 1500 GPH. The 3000 box uses dual 2" bulkheads and is rated for 3000 GPH.
It does, to a point. It is kind of the law of diminishing returns. Take a box with 12" of flow surface, if you go to 24" you double your theoretical surface skimming ability (in reality is is much less due to water's coadhesion properties). Take that to 30" and you get a minimal increase over the 24", virtually nothing in the real world (we have tested this). Think of your average swimming pool with a 12 inch overflow, the whole surface is skimmed in a matter of hours. Skimming is a function of flow rate much more so than weir length, especially in the very small surface area of any home aquarium.
No, we no longer make non standard boxes. Our designs have been tested and proven in thousands of installations. We don't want to send an untested product to our customers.