HOB Overflow help

[Lgara1303]

Needing to get a HOB overflow for my dads tank to make it into a sump his tank is 46 gallons and the sump will probably add 10 so let's say about 55Gallons my question is, is a 300gph Overflow going to be enough or do I need more the only other one I can find is a 800 GPH which I think is to much for that size but let me know what you guys thinks. The 300 would be a turnover rate of about 5-5.5 so

 

[jft]

Eshoppes overflows are reliable . I have used them for years on various tanks with good results. Lifereef make also reliable overflows but are more expensive and larger in design. Make sure you use an adjustable pump with a valve to adjust the flow and Test various overflow scenarios. Drilling a tank is alot better but it takes skill. Good luck.

 

[Lgara1303]

Eshoppes overflows are reliable . I have used them for years on various tanks with good results. Lifereef make also reliable overflows but are more expensive and larger in design. Make sure you use an adjustable pump with a valve to adjust the flow and Test various overflow scenarios. Drilling a tank is alot better but it takes skill. Good luck.

I have drilled my frag tank and went well however this tank is filled there is no way to drain and drill even if you partially drained still have glass get into the tank so this is really the only option.

Can you recommend if the 300 GPH will work

 

[vlangel]

Yes, 300gph should be enough and you can always add a powerhead if you want more water movement in the tank. That being said, I have a 56 gallon tank and I am using the 800gph HOB overflow. I don't have 800gph coming out of the return nozzle however, it's about 400gph. As long as it's enough that you do not get bubbles building up in the U tube it's good. 400gph is about the minimum flow that will keep bubbles from building up. I use a variable speed pump to dial that in. My overflow is an Eshopps as well and has never failed.

 

[Lgara1303]

Yes, 300gph should be enough and you can always add a powerhead if you want more water movement in the tank. That being said, I have a 56 gallon tank and I am using the 800gph HOB overflow. I don't have 800gph coming out of the return nozzle however, it's about 400gph. As long as it's enough that you do not get bubbles building up in the U tube it's good. 400gph is about the minimum flow that will keep bubbles from building up. I use a variable speed pump to dial that in. My overflow is an Eshopps as well and has never failed.

He has a powerhead in there so I am not worried to much about the flow or movement as I am making sure it will turnover enough. So you're saying the MIN is 400GPH to keep bubbles out makes me think the 300 would cause them or have some problems I wish there was a overflow in the middle at like 500-600 but none of the HOB options I have seen has been that.

 

[vlangel]

He has a powerhead in there so I am not worried to much about the flow or movement as I am making sure it will turnover enough. So you're saying the MIN is 400GPH to keep bubbles out makes me think the 300 would cause them or have some problems I wish there was a overflow in the middle at like 500-600 but none of the HOB options I have seen has been that.

Bubbles build up if the flow through the U tube is not fast enough. If the flow through the U tube is faster than the drain of the HOB overflow can handle then it creates a flushing noise like a toilet. So I have found with my Eshopps 800 that about 400gph coming out of the nozzle is the minimum flow that keeps bubbles from building up. That is why a variable speed pump can help. You can start slower and watch the U tube to see if bubbles are building up. If they are then adjust the controller of the pump to increase the flow. Of course you want to choose a pump that is in the right range. And don't forget that head pressure (due to the height from the return pump in the sump up to the return nozzle) will lower the flow.