Converting AIO into a HOB overflow with sump

[Fishlover56]

Hi all,

I am wondering what everyone thinks I have got a 105litre tank which I built a DIY AIO in luckily for me I only used silicon so I can get the acrylic apart ok and hopefully with a razor I can get some of the silicon off the glass although I will accept the fact I might not be able too.

As with DIY most of the time it ain't as good as the real deal and mine doesn't function as I like due to the flow patterns.

I would like to add a small tank underneath as a sump. However, as the tank is mature I dont want to mess with it too much aka drilling holes.

How easy is it to install a HOB overflow box with air assist priming?

I have heard that they can flood?

Does anyone know if this could be good? Even if I installed a sensor that could pick up if water started to come out etc and maybe return pump's that can detect and stop if they ran dry.

 

[Quietman]

Failure here means water on the floor. Reliable means flow keeps moving through sump and display.

HOB overflows are very reliable and failure free if set up correctly. Basics of sump design apply. Design sump to take all the display level change when you turn off return pump. Make sure your sump return section can't overflow the tank in case you lose the drain (siphon break).

People have operated HOB overflow for years without failure. I am planning one for next build. Don't want to drill tank.

Two major types of HOB OF exist. First is U tube. Very reliable as long as you have sufficient flow to keep bubbles from collecting at the top of the U tube. Don't go too far under rated flow.

The other kind is the box type which rely on additional pump to ensure no air lock occurs. This really isn't unreliable although it has more components so risk would technically be higher. But again, properly designed with a pump suction that both removes air and can't overflow sump can be reliable and failure proof.

Both will require you to inspect occasionally during routine maintenance to ensure proper operation. That's pretty standard with a lot of tank equipment.

 

[exnisstech]

I ran a 180g for over 6 years using two hob overflows. I ran eshopps hubs that use u tubes as mentioned above. A lot of people that never ran a hob overflow will say they are terrible and flood if the power goes out. Mine never lost syphon when the return pump was turned off. They only way i could cause a flood with mine was if I cranked the return up so it was pumping more than the overflows could handle.