Pump to overflow ratio?

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

jessicasmarine

Aquarium Advice FINatic
Joined
May 30, 2009
Messages
660
Location
MCRD PI, SC
Hello again, I just bought a pump today and installed it in my wet/dry filter. But the pump drains my W/D Filter faster than my overflow can fill it. :confused: I don't kow the GPH of the overflow(hang-on type with 1" U-tube and 1" stand pipe) but the pump is 850gph at 4 ft. How can I adjust the flow out to match the flow in? TIA
BTW Happy Flag Day, Hold Em High:usa
 
Your overflow should have a least a 1" line (or larger) to the sump as straight a possible. Your return line should have a siphon break just above the water line when the pump is off (to keep your sump from flooding). You could install a ball valve on the pump output to restrict flow or a "T" and a valve to a return back into the sump. Do you know the flow rate of the overflow box?
 
1" drains at 600gph.

Use the ball/gate value advice above or get a different pump. A mag 9.5 would pretty much handle it right out of the box.
 
be careful of the pondmaster, they are not magnetic drives. Even though they are sealed they contain oil. Thats' what accounts for the difference in the price between the models. On Ebay (and other places) you'll see a lot of people pricing/selling them at the same price as the aquarium model.
 
be careful of the pondmaster, they are not magnetic drives. Even though they are sealed they contain oil
Are you sure cause it says powerful magnetic drive. No seals to wear and no oil, and it also has a magnetic impeller when i take it apart. Maybe they changed their production.
 
Not saying cheap but the PM 9.5 is probably in the 60-80 range online where the mag (I forget the letter designation) is closer to 100-120-ish. Note the '-ish'.

My only point was that there is some exposure there w/ the PM version.
 
wow, all 3 LFS here had for about the same at 190, I got it cause I went with the cheaper isnt better theroy and figured the extra $ would have got me something better.
 
wow, all 3 LFS here had for about the same at 190, I got it cause I went with the cheaper isnt better theroy and figured the extra $ would have got me something better.
IMO, getting a new pump or an overflow rated for the pump is the answer not restricting the return with a valve which would cause the pump to run hotter and burnout sooner. Another possible problem would be cavitation which would throw tons of bubbles into the tank which is all bad.
 
God Bless if you were to find the exact pump to go with your overflow at the exact head height using the exact amount of piping and connectors to even everything out. I venture to guess many don't.
 
IMO, getting a new pump or an overflow rated for the pump is the answer not restricting the return with a valve which would cause the pump to run hotter and burnout sooner. Another possible problem would be cavitation which would throw tons of bubbles into the tank which is all bad.

Just to clarify....

Placing a valve on the discharge of a pump would only cause stress to the pump if you pinched it so far closed that almost no water is being moved. In fact, throttling a pump back (to some extent) makes it do less work, causing it to use less power.

Cavitation happens in high to low pressure transitions. Again, you would have to have this pump cut so far back that it is moving only a slight amount of water compared to it's rating. Even then I somewhat doubt that these little pumps can produce enough velocity through a valve to cause cavitation.

Using a valve on the discharge of a pump is done quite often, especially in this hobby.
 
God Bless if you were to find the exact pump to go with your overflow at the exact head height using the exact amount of piping and connectors to even everything out. I venture to guess many don't.
If your overflow is big enough then you can use the valves on the supply side to control the amount of flow through the sump without restricting the return side and stressing the pump.
 
IMO, getting a new pump or an overflow rated for the pump is the answer not restricting the return with a valve which would cause the pump to run hotter and burnout sooner. Another possible problem would be cavitation which would throw tons of bubbles into the tank which is all bad.

While that's always an option as long as it's a non drilled tank (which this is; not drilled), that's not exactly the advice I was commenting on.

Enjoy
 
Just to clarify....

Placing a valve on the discharge of a pump would only cause stress to the pump if you pinched it so far closed that almost no water is being moved. In fact, throttling a pump back (to some extent) makes it do less work, causing it to use less power.

Cavitation happens in high to low pressure transitions. Again, you would have to have this pump cut so far back that it is moving only a slight amount of water compared to it's rating. Even then I somewhat doubt that these little pumps can produce enough velocity through a valve to cause cavitation.

Using a valve on the discharge of a pump is done quite often, especially in this hobby.
Unless the pump is of variable speed via an external controller it will run at 100 percent no matter what, and as far as saving power that is highly unlikely unless you are using some sort of variable frequency drive (Only for AC current motors) to adjust the frequency (will save you money) not a resistive load which controls the voltage and only distributes load from the motor to the resistive load hense still using the same amount of power
but is now distributed between two devices. I understand that valves are used often on the discharge side but really shouldnt be used to control the flow.
 
if your pump is too strong, T off of it with an extra line going back to the front side of your sump with a valve to adjust the flow. It will allow you cheaply fix your problem as well as give your sump more flow. There is no need to do anything electonically complicated.
 
IMO throttling back a pump is no different than using more head hight, as long as your not closing the valve too much. As I stated before you could add a "T" fitting using the Valve to restrict a return line back into the sump.
 
Back
Top Bottom