"Feed" pump to replace an overflow?

Agreed with everyone else. It will not work. If you have two pumps that pump lets say only 500gph and one pump is only 0.1% stronger than the other the difference will be a half gallon per hour, thats 12 gallons in a day difference, will overflow all but the largest displays/sumps in the first few hours. There is not a control valve on the market that is able to control flow rate in such small numbers.

The "hang on the back wet/dry filters" you are talking about DO have an overflow. The water gets pumped from the display via powerhead into the HOB filter, then it overflows from the hob filter BACK into the display)

If after reading this you still want to try it go ahead, but please And I mean PLEASE, Ensure ALL powerstrips are mounted on the wall at least 6inches away from all aquarium walls and there is a drip loop on ALL of the cords. Also if you live with your parents or a significant other tell them "I am going to flood the house today, so please don't be mad."

 

Just to add another perspective here, you will never be able to match the flow between two pumps.

The amount of flow will vary slightly with each pump over time, as algae builds up in the tubing/plumbing, or as some calcium precipitates out onto the pumps which will slow it down slightly. It will not do this at the same rate so even if you get them dialed in for a day or two you will find them drifting apart.

Good luck, but I think it will end up being more trouble than its worth having to constantly worry about that.

 

To get this to work, you would have to be constantly balancing and rebalancing the flow rates for the pumps, either through a ball/gate valve or whatever. You're trying to replace money with an "easy way out", however in reality you will be replacing the extra money spent on a decent overflow with a whole lot of time, headache, and potentially a TON of money down the road.

Personally, I wouldn't be able to sleep with a setup like this running in my house. What if something happens in the middle of the night and one pump slows down? That's asking for a flood. What if one pump fails? That's asking for a flood.

You better hire someone to balance the flow rates 24/7 if you can't listen to that logic.

You can find a U-Tube style overflow (what we use) for $30-$50 online or even at an LFS. As long as you have a high quality Utube and keep it clean, there's no reason for those to fail. We've had ours running for 7 months, and a friend of mine's is pushing 3 years, no trouble. Just buy an overflow and save your brain from rotting out due to the worry and headache that will insue.

 

I was in your shoes long time ago, when I was looking for a cheap overflow. I did consider an idea like yours, until I really thought about it, and knew it was going to lead to failure. While doing some research, I found this thread Nice Cheap DIY Overflow on 3Reef.
It doesn't get any better then this when it comes to being cheap and reliable. I built this overflow for about $20, and it is running smooth for a little over 2 years. I never had a flood. It is very quiet. I would recommend you ditch your idea about running two pumps, and stick with a tried and true method.

 

Not so, the one at my LFS uses a feed AND return pump. I specifically checked to see if they were using some sort of drain back or overflow.

I will try it myself. If it fails miserably, I'll still tell you guys so nobody repeats my mistake.

Your concern is very much appreciated. This isn't really about saving money, but more trying to look for new ways of doing something.

 

Well, good luck with that :-/.. At least do me a favor, and read about the Cheap DIY overflow...

 

Just out of curiosity, what kind of flooring do you have your tank on? It must be tile.

 

Are you talking about a hang on back system? A HOB protein skimmer perhaps? Because there's no physical way you could get a system like that to cheaply work going from the display tank down to a sump below the tank and then back up again. When you just think it through, you know there's no way it can work without some sort of precision flow control and sensors placed on the tank or something like that. Which isn't cheap at all...

If you are still going to try this from a display tank down to a sump...well...here's a little piece of advice that might help you out some...





I saw a commercial for that today and for some reason I thought of this thread

 

Ehh, go with Zorbeez!!

Act now and we'll double the offer, just pay shipping and handling!!

 

I think you are confusing a feed pump with something like an aqualifter, which is a siphon assist. Looks a lot like a pump, but merely keeps the siphon going (needed with something like CPR overflows).
I also dont have experience running my halides under water to increase par values, but I dont think you should try that, either.