It doesn't seem like it is pulling that much. Do you have your fuge plumbed to drain into the return section of you sump or does it all go through the skimmer first.
Return Pump Question
- Thread starter ruppertb
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ruppertb
Valuable Member
overflow goes to 20gal holding tank for water changes which goes to a filter sock and skimmer area.
overflow also feeds 20 gal frag tank which returns to last 55 with cheato tumbler
overflow feeds 20 gal fuge tank which returns to last section of skimmer tank and then feeds into cheato tumbler
overflow also feeds 20 gal frag tank which returns to last 55 with cheato tumbler
overflow feeds 20 gal fuge tank which returns to last section of skimmer tank and then feeds into cheato tumbler
Well if you are trying to keep pods then this want work but recirculating threw the sump would be a good way to go. Your skimmer would be able to get some of what it missed. But again pobs would be caught by the skimmer.
reefrooster
Community Member
I had a eshopps overflow box that had a similar problem. Check the tube that goes from the front box to the rear box the tube sometimes developes a small crack in that tube. In mine it killed the flow rate. I believe yours has two of those tubes.
ruppertb
Valuable Member
mine has one tube, i doesnt develope any bubbles though so im not sure about a crack, i will check though, i have a few of the u tubes in different sizes. maybe a bigger one will help.
See I'm glad someone else stepped in because in don't know squat about HOB overflows. Other than most are not good for power outages. My guess would be the bigger tube would siphon more water.
mcarroll
10K Club member
Ok, while IANAElecrician or Engineer (capital E), I've read up a little on this and have some experience as well....here's the scoop so far as I know it.
Relevant terms: Power Factor
The motor of your pump will stay "fully charged" no matter what the impeller is doing and this is where most of the heat that our pumps generate comes from. This is measured in VA, or Volt-Amps, and is what you get when you combine the volts and amps from any electric motor type of device's silver power label. For us residential users, this mostly matters to our breaker box and the capacity of the circuit our pump is on - it's not what we are billed for though. That's watts. Watts are what is consumed as the impeller spins, and this is what we get billed for - the actual work. Slow a pump down as yours is and the impeller does not spin as fast nor push as hard, so not as many watts are used.
So, where would a pump be damaged in being run like this?
The only real thing to worry about is heat - and we know where this comes from. If your pump is designed to be water-cooled and almost all the ones we use are, you can actually burn out a pump by not having enough (or any) water flowing through it....that is literally burned up due to heat build up in the motor coils to the point that the metal (copper) coils crack and no longer make a circuit. To wit: Do not plug in a MaxiJet without its impeller and then walk away.
Some higher-end pumps actually have an active circuit monitoring motor temp and will shut a pump off to avoid damage.
By extension, if there is some significant water flow (which you have), then while there may be greater heat transfer to the water in the pump (same net amount to the system, but water exiting the pump will be warmer), the pump should be fine. Within limits of course....if the water going in was 150ºF then you're not helping, but ~80ºF water should be able to cool the pump just fine.
So, if you were to have a Mag 18 and were only getting 2 gph from it, I might be concerned about overheating the pump. If there are still ~600 gph running through it, I'd bet you will be fine running it mostly closed.
If you still want to trade it out, the Mag 18 would make a rockin salt mixing pump!
Concerning the overflow....as you've discovered, the number ratings are "wishful". Not to say that 800 gph couldn't be done.... You might hit 800 gph with a straight PVC pipe running straight from the overflow to your sump that's of equal or greater ID to the overflow's bulkhead. But you better like fiddling around to eliminate rude flushing and sucking sounds all day and all night as siphons form and break (and form and break...) and you better like a lot of churn in your sump as all that air that got mixed in bubbles out and created salt spray on everything around your sump.
If your overflow is rated for 800 gph, I'd target around 500-600 gph of flow so that it runs silent. If you want more flow, then get a second overflow (was my solution), or insert a second U-tube to maximize flow through your current overflow if there's room for it. Of course, this will not help your drain speed, if that happens to be your limiter....that'll take a bigger, or second, bulkhead and accompanying plumbing changes. If you find that you can't get even the 500-600 gph range without flooding, then you need to look again at your overflow's plumbing to the sump - too many zig zags, or too small of plumbing, or both.
Take a bucket to the basement and measure (time) the actual output of your drain and let us know what you're actually draining now. I'm curious!
-Matt
P.S. FWIW, I actually had a one of those overflows (PF800) and returned it cuz it wouldn't hold a siphon during a power-down to save its own life. I'm not a fan. If you haven't, make sure you test yours thoroughly!
Relevant terms: Power Factor
The motor of your pump will stay "fully charged" no matter what the impeller is doing and this is where most of the heat that our pumps generate comes from. This is measured in VA, or Volt-Amps, and is what you get when you combine the volts and amps from any electric motor type of device's silver power label. For us residential users, this mostly matters to our breaker box and the capacity of the circuit our pump is on - it's not what we are billed for though. That's watts. Watts are what is consumed as the impeller spins, and this is what we get billed for - the actual work. Slow a pump down as yours is and the impeller does not spin as fast nor push as hard, so not as many watts are used.
So, where would a pump be damaged in being run like this?
The only real thing to worry about is heat - and we know where this comes from. If your pump is designed to be water-cooled and almost all the ones we use are, you can actually burn out a pump by not having enough (or any) water flowing through it....that is literally burned up due to heat build up in the motor coils to the point that the metal (copper) coils crack and no longer make a circuit. To wit: Do not plug in a MaxiJet without its impeller and then walk away.
Some higher-end pumps actually have an active circuit monitoring motor temp and will shut a pump off to avoid damage.By extension, if there is some significant water flow (which you have), then while there may be greater heat transfer to the water in the pump (same net amount to the system, but water exiting the pump will be warmer), the pump should be fine. Within limits of course....if the water going in was 150ºF then you're not helping, but ~80ºF water should be able to cool the pump just fine.
So, if you were to have a Mag 18 and were only getting 2 gph from it, I might be concerned about overheating the pump. If there are still ~600 gph running through it, I'd bet you will be fine running it mostly closed.
If you still want to trade it out, the Mag 18 would make a rockin salt mixing pump!
Concerning the overflow....as you've discovered, the number ratings are "wishful". Not to say that 800 gph couldn't be done.... You might hit 800 gph with a straight PVC pipe running straight from the overflow to your sump that's of equal or greater ID to the overflow's bulkhead. But you better like fiddling around to eliminate rude flushing and sucking sounds all day and all night as siphons form and break (and form and break...) and you better like a lot of churn in your sump as all that air that got mixed in bubbles out and created salt spray on everything around your sump.
If your overflow is rated for 800 gph, I'd target around 500-600 gph of flow so that it runs silent. If you want more flow, then get a second overflow (was my solution), or insert a second U-tube to maximize flow through your current overflow if there's room for it. Of course, this will not help your drain speed, if that happens to be your limiter....that'll take a bigger, or second, bulkhead and accompanying plumbing changes. If you find that you can't get even the 500-600 gph range without flooding, then you need to look again at your overflow's plumbing to the sump - too many zig zags, or too small of plumbing, or both.
Take a bucket to the basement and measure (time) the actual output of your drain and let us know what you're actually draining now. I'm curious!
-Matt
P.S. FWIW, I actually had a one of those overflows (PF800) and returned it cuz it wouldn't hold a siphon during a power-down to save its own life. I'm not a fan. If you haven't, make sure you test yours thoroughly!
Last edited:
mcarroll
10K Club member
That's urban legend that is sadly sort of good advice given the quality of some products on the market. It's certainly a valid concern, however, and any installation should be tested multiple times to make sure a power outage has no unexpected side-effects. I'm going on my third version of this type of overflow (one Amiracle, one no-name, and my current Hurricane Filters) and about 20 years of on/off cycles....never had a siphon break outside of testing of the previously mentioned overflow.
Thing is, the Eshopps is a Chinese knockoff of a general design that's been around since at least the early 90's....possibly before that....and there's nothing in that design that makes it susceptible to power outages. But that doesn't speak to the implementation of that design. If Chinese knockoffs have a weakness, it's usually in the implementation, not usually in what design they choose.
Lifereef is the only company left (to my knowledge) that's known to make high quality overflow boxes. In addition to Lifereef, ADHI and Aqueon both appear to be making a version of this overflow design...if Lifereef is outside of one's budget, I'd be inclined to try one of these two before other available options. Sadly when the aquarium market crashed, my favorite (Hurricane Filters) went out of business.
Anyway, back to the urban legend... Quite simply, if the two ends of the U-tube cannot get to any air (i.e. they are forced to remain submerged at all times) then there's no chance of a siphon break. None.
A good overflow takes this into account with a good system (usually stand pipe, or weir) for maintaining a water level well over the U-tube openings.If your tank's pump was off long enough for evaporation to take enough water out of the overflow boxes to expose the siphon to air, then maybe, but that would be a pretty long time to leave most any tank unattended regardless of chosen drain type.
-Matt
reefrooster
Community Member
Also check your filter in the back box. If its dirty or worn out it won't flow right
See I told you I didn't know anything about them. My tank I'm supposed to be able to push 3000 gph through it but I have a 2" bulkhead. This by a bulkhead flow chart that was posted on here in the last week or but I that big thing in so if my turbo goes down he want clog it as easily. And yes it is noisy when the canopy is open but it give me piece of mind knowing it want clog. I don't have anything against HOB overflow just never thought to use one since it is easy for me to drill my tanks. With my mag 18 throttle half way back at night I still need a heater so there isn't much heat. As far as damage keeping it throttle back I was just being safe but pulling the same watts either way I would go with a smaller pump if you don't figure out the over flow.
ruppertb
Valuable Member
Ok thanks for all that, it was helpful.
I dont have a prefilter on overflow so it wont get cloggged.
I would love to measure the flow rate of the drain pipe but the tank it drains into is right against the ceiling, not much room.
I have had the overflow box for 4 yrs and never had it fail, only acumulated bubbles if flow is too slow.
Ya at the moment I have 550watts of heaters in the sump and it is stabalized at 77.8 I think I need to add one more heater. Or maybe the hallides will help during the day, and then i will have to see how much it drops at nights.
I dont have a prefilter on overflow so it wont get cloggged.
I would love to measure the flow rate of the drain pipe but the tank it drains into is right against the ceiling, not much room.
I have had the overflow box for 4 yrs and never had it fail, only acumulated bubbles if flow is too slow.
Ya at the moment I have 550watts of heaters in the sump and it is stabalized at 77.8 I think I need to add one more heater. Or maybe the hallides will help during the day, and then i will have to see how much it drops at nights.
yeah i was bored so i decided to write a book. lol
Have any luck yet ?
ruppertb
Valuable Member
its stable at a little over half open, been stable all weekend while i was 7 hrs away. came home to a silent tank and no leaky pipes, and hardly any evap in the sump now that its in the cooler basement
Sweet. With all that in the basement you shouldn't need a chiller. At least I don't think so. I have know clue how hot it gets there. Glad your up and going. Oh yeah with everything else did you ever find time for that frag. If not that's cool, I forgot about until now.
denrobare
Community Member
I am having a similar issue with my pump. I just picked up an established 30g sump. Intake/Refug./Return section. The pump I bought is rated at 1000gph and the overflow box is rated up too 1200gph. I dont have my stand or display tank ready, so the thought was to allow the pump to just circulate the water through the sump, problem is, the pump is so powerful its like a raging river running through the sump. I ended up just shutting it off for now and put a small hang on filter in the fuge to keep the water circulating. I lost some copepods for sure, not sure if all of them are gonners.
I believe I am going to have to likely T off the return if the overflow doesnt perform as advertised. We'll see.
I believe I am going to have to likely T off the return if the overflow doesnt perform as advertised. We'll see.
no rush. fedex and ups like leaving stuff on my porch so i just wanted to know when it ships. like said know rush at all.
No, valving the discharge side of a centrifugal pump often makes them more efficient in fact. It will not hurt the pumps in any way to valve them back ever to 1/2 flow as long as it is the discharge and not the suction.
Throttling of adding head to the discharge sometimes brings the pump into its best efficieny point so you get a more efficient pump which means less heat and lower power consumption.
Teeing off and returning flow to the sump is a bad idea and leads to higher power consumption, more heat and lower efficiency. The reaason is the pump is doing more work even though you are only using a protion of the flow. Its hard to grasp but it has to do with two theorys or laws, Bernoulis Theory and The Laws of Affinity, both of which apply to all centrifgual pumps regardless of size or volume.
Throttling of adding head to the discharge sometimes brings the pump into its best efficieny point so you get a more efficient pump which means less heat and lower power consumption.
Teeing off and returning flow to the sump is a bad idea and leads to higher power consumption, more heat and lower efficiency. The reaason is the pump is doing more work even though you are only using a protion of the flow. Its hard to grasp but it has to do with two theorys or laws, Bernoulis Theory and The Laws of Affinity, both of which apply to all centrifgual pumps regardless of size or volume.
mcarroll
10K Club member
If anything you should get more evap, not less, because the water is still ~80º so the differential with the air temp in the basement is actually higher, not lower. (You really need a cover on that sump to cut evap....lotta times it's better to live with high evap.)
If you actually are seeing less evap you may have a lack of air exchange in the area - your air is already "filled up with water". This is "good" for mold growth.
Regardless you should get a hygrometer or two and keep an eye on your humidity down there. Analog or digital would be fine - nothing fancy required. Humidity in the basement shouldn't be much different than the rest of your house. In a place where it gets COLD like Wisconsin, ideally around 40% humidity for no mold issues, but could need to be much less depending on how cold it is outside.
-Matt
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