Anyone Using Overflow Boxes For There Sumps?

[Fluval-1200]

As per title really... my tank is freshwater but il get more answers in here regarding sumps and overflow boxes/
 
Main question are they reliable?
 
And anyone got a couple pictures of there current overflow box setup.
 
 
Thanks in advance.

 

[Donya]

They are as reliable as you set them up to be really. You can add safety guards to just about any overflow to ensure that all the possible points of failure are covered in some way. I've been using an overflow on my 55gal for a few months now, although my only picture of it isn't that great.
 

 
 
If you have a high flow-rate overflow, it might be trustworthy as-is, but mine is rather small and I didn't trust it on its own, since the flow wasn't fast enough to ensure that bubbles got sucked away. You can see a bubble in the top of that pic actually; it was taken just after I'd started testing it. My overflow is only about 300gph I think; I imagine faster ones would not have that problem, since it's an issue of getting the water flowing fast enough to sweep bubbles down. To deal with that, I got one of those little pumps that can both prime the siphon and keep air bubbles out of it, and it has been trustworthy since that. You insert a small bit of airline tube up to the highest point of the bend and connect it to the pump. Also, if you get an overflow with a sponge filter like mine has to stop large debris from going into the drainage pipe, you need to clean that regularly as well or it will get hinder the flow out of the tank. Soon I'll be also getting a water level sensor for the sump to turn off the return pump if anything clogs the siphon or drain pipe (like an animal crawling into it, which is probably more of a marine risk than a freshwater one).

 

[Fluval-1200]

Thank you donya for the picture and answering my questions . Is the siphon easy enough to start without the pump? and if you was to lift that tube would it effect the flow or anything?
 
Just trying to get my head around it all and design it to fit my award lid lol

 

[Donya]

Unfortunately I found the siphon an incredible pain to start without the pump. You have to put a bit of airline tube up the siphon to the same place and then suck out the air by some other means, usually by mouth. I got fed up with that quite fast, particularly since I could never seem to get all the air out that way...some would always sneak back in as I was trying to either cap off the airline or remove it. 
 
The siphon tube can be lifted (you can also lower the black box inside the tank, which lowers the waterline; same effect as far as distance the water is traveling), but it slows the flow a slightly the bigger the gap is between the waterline and the bend in the tube. If it only needs to be lifted a little though, I don't think you'd see much difference, particularly if the waterline was high.