High Tide Aquatics

HOB overflow in AIO tank

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vissen319

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Hi all,

I managed to get a HOB overflow that fits very nicely in my 40 gal AIO tank. However, I am having a hard time keeping the desired water level in the overflow. I am dialing my pump and the return valve on the drain and overflow but the liquid level tends to decrease with time (about 4-5 hours). The overflow is rated for 600 gph and my return pump is rated over 1000 gph.

I did not do much inside the tank except remove my return line for my water pump inside the AIO. So, there is room for improvement. I did not do this because I did it the lazy way due to livestock and corals inside the tank and I did not want to drain the tank.

I feel that the flow is being restricted by the ~ 1/2 inch hole (that used to be the fitting for my return nozzle) in the acrylic baffle inside the AIO. What do you think about this? All suggestions are welcome.

Should i empty at least part of the tank and drill a bigger hole inside the acrylic? or i can make a weir on the top to skim the surface as well?

Thanks!
 

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You added an overflow box to add a sump?
My suggestion would be drill the back of the tank and have a real overflow box setup rather than the hob
Are you getting bubbles built up in the tube for the overflow box?
Let’s see a pic
 
Yes, i did add the overflow box to add the sump. I am aware of that method but I was not keen on drilling the tank because it is a big hassle after having livestock in.

Inside the overflow, I do not have bubbles. In my drain pipe, there is some trapped air. That is because i had to regulate the drain valve. The overflow is draining faster than the water intake. So, at some point the water level inside the overflow becomes very low and very noisy.

i will take some pics later today.
 
Did you want greater volume of sump than what is already there in the back of the AIO? Just curious. I hope to never use my HOB overflow again bc it was always dicey having it dialed in. Then again, I did not have an ATO.

What really helped though was an airline nipple installed in the top, as shown. Does yours have this? I added one when I used a different HOB on an earlier tank and it also worked.

Explanation found online: “Connect the nipple on top of the overflow to the inlet of the Aqua Lifter using airline tubing. Attach another piece of airline to the outlet of the Aqua Lifter. The outlet line may be placed in any of three places for drainage: the tank, the sump, or the overflow. Ensure that the end of the outlet line remains under water. This will prevent air from entering the system if power is lost or the pump malfunctions. The Aqua Lifter not only constantly draws out air which can stop your siphon, but after a power outage they can restart the siphon when the power comes back on.” You can also use a strong powerhead with a little Venturi attachment.
 

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MolaMola said:
Did you want greater volume of sump than what is already there in the back of the AIO? Just curious. I hope to never use my HOB overflow again bc it was always dicey having it dialed in. Then again, I did not have an ATO.

What really helped though was an airline nipple installed in the top, as shown. Does yours have this? I added one when I used a different HOB on an earlier tank and it also worked.

Explanation found online: “Connect the nipple on top of the overflow to the inlet of the Aqua Lifter using airline tubing. Attach another piece of airline to the outlet of the Aqua Lifter. The outlet line may be placed in any of three places for drainage: the tank, the sump, or the overflow. Ensure that the end of the outlet line remains under water. This will prevent air from entering the system if power is lost or the pump malfunctions. The Aqua Lifter not only constantly draws out air which can stop your siphon, but after a power outage they can restart the siphon when the power comes back on.” You can also use a strong powerhead with a little Venturi attachment.
Click to expand...
Thanks a lot. Yes I am using the cpr overflow with an aqualifter pump. Indeed I want to have more stability in my tank and having a sump will increase the overall volume not mentioning all the nice stuff that you can do with a sump.

I spent some time tonight dialing both the intake and the drain. It looks like I had some air down the line. Not inside the overflow but somewhere down the line.

I have monitored the level for about 3.5 hrs and so far it has been good. Attached are some pics. Not great plumbing wise but it works. I need to find a gate valve at some point.

20210713_205805.jpg


20210713_205819.jpg
 
Coral reefer said:
You added an overflow box to add a sump?
My suggestion would be drill the back of the tank and have a real overflow box setup rather than the hob
Are you getting bubbles built up in the tube for the overflow box?
Let’s see a pic
Click to expand...
Thank you. I think I managed to dial it a bit more tonight. So far so good.

Can I create a weir on the acrylic? I have placed the overflow in my return chamber in my AIO due to its size. So I no longer have a weir. I was thinking of using a Dremel to create some slots in that black acrylic panel. What do you all think?

20210713_205955.jpg
20210713_205916.jpg
 
There is but that chamber is now being used as my return chamber. I had to swap the two sides because the overflow would not fit inside my drain chamber(the one with the weir).

Sorry if that is confusing.
 
I think making a weir is difficult. If you were going to drain or lower/try to cover water to make the slots, it seems easier to drill the back or enlarge the return hole as others have said and skip the overflow.
Maybe others have some weir tricks up their sleeves.
 
Yes for now I swapped the return and drain due to the size of my overflow.

My return is on the left hand side where my weir is.

I bought 2 gate valves and an acrylic jig saw blade. Will try to create a weir on the original return chamber. Will plumb the tank again this weekend.
 
Hi all,

I just wanted to give you an update on what I did following my last post. In case that can help others to silence their HOB overflow if needed. I did some research and realized that I may probably have not been able to silence the overflow or probably need a big pump to get
the adequate amount of water. My sump is in my basement and there is a large drop.

So, I built a stockman pipe....it is awesome. And it is very silent too. My water level in the overflow has been constant for over 2 weeks. Two days ago, there were some intermittent power outage by crappy pg&e. It started fine without any problems. I didn't even know that there were outages until my wife told me about it.

With the stockman, I could dial the water level to the desired height by drilling the drain holes higher or lower.

here is a pic . I did this rush job in about 20 min. You can see that the slip fitting is not even sitting straight. I did not have the right size and I took one of my return pump fittings to make it sit on it. It could be more silent if I drill the holes in a more regular fashion. The holes are covered by the slip fitting.

i still plan to remove the back acrylic. I tried to remove some silicone with a scraper blade and it looked easy...so far.

thanks all!
 

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