Eshopps HOB Overflow 800 issues

[John Haigh]

Hello all! I recently installed a HOB overflow rated for 800 gallons. I am using an Apex Cor 15 rated to 1500 gallons. I have experienced overflow both in my sump and in my tank. Dialing it in to avoid the overflow has resulted in a loud noise coming from the overflow, lowered display tank level, and the sump filling above it’s designed height. Any help would be sincerely appreciated!
Thanks so much!
John

 

[shwareefer]

The sump has to have extra space for the water to drain for a power failure. It should never be able to overflow. It is either too small, there is too much total water in the system, or drain lines ( including the return when power is off) are too deep in the display tank.

I've never used a HOB overflow but it sounds like you have reduced the flow too much and the drain is ahead of it. Also by the looks of it, you can raise the black box to set the water height in the display. I assume it's this one:

 

[John Haigh]

Thanks so much! That is the overflow I am using. I made the sump in a 20 gallon long and have a 75 gallon DT. I am using a Clarisea sk-3000 and set the sump with 9” baffles with 1” gap at the base. I went the DIY route and perhaps that’s adding to the issue?

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[John Haigh]

Here is the sump

 

[shwareefer]

I'm all for DIY. With 9" baffles, you only have about 5 gallons of overflow from a 75 gallon tank ( and really less considering the displacement from sump equipment). That means if the display drains around 1.5 inches you are out of room in the sump. If you can have your return line only 1/2" in the water and your overflow wier similarly high you might be able to swing it. Keeping a lower level in the return pump chamber can buy you some space too. This is not including that you likely are going to have a skimmer and that is also going to dump water back during a power failure. You did a nice job on the sump but personally I would have gone bigger for a 75 display.

 

[John Haigh]

I'm all for DIY. With 9" baffles, you only have about 5 gallons of overflow from a 75 gallon tank ( and really less considering the displacement from sump equipment). That means if the display drains around 1.5 inches you are out of room in the sump. If you can have your return line only 1/2" in the water and your overflow wier similarly high you might be able to swing it. Keeping a lower level in the return pump chamber can buy you some space too. This is not including that you likely are going to have a skimmer and that is also going to dump water back during a power failure. You did a nice job on the sump but personally I would have gone bigger for a 75 display.

Thanks so much- I see what you mean. If I reduced the baffles by 1”, do you think that would be enough?

 

[shwareefer]

30*12*1/231=1.56 gallons. Every inch will gain you 1.56 gallons. Do you know what skimmer you are going to use and it's recommended depth?

 

[John Haigh]

I am keeping the hob skimmer for now. I am still running my fluval F6 with bio balls and pond matrix. I thought adding the sump would allow for more water for stability. I have a hob refugium too. I was going to try and grow that in the sump.
I was fresh water for 35+ years and made this transition uneducated. I’ve learned a lot over the last 8 months! You’re helping quite a bit! Thank you!

 

[shwareefer]

If you are not running a skimmer in that middle chamber then you can lower the one baffle before the return pump to say 7 or 6 inches. Minimum modification for a decent gain.

 

[Snoopy 67]

John,
You have to know that almost all sumps have a running level of around 1/2 capacity to allow for drainage on a shut down. So consider your 1st sump as a building lesson & get a new one to ease your mind as a solution.
Watch out for nitrates with that Fluval. Live rock does the filtration in saltwater.
The water evaporation in a sump shows up in the return pump section so that is where you want your auto top off positioned. If it's too small you could run into the pump emptying it too fast.
As you can see the bigger the sump the better.

 

[John Haigh]

If you are not running a skimmer in that middle chamber then you can lower the one baffle before the return pump to say 7 or 6 inches. Minimum modification for a decent gain.

Awesome! I’ll do that!