# return pump from sump too powerful, options?



## chiroken (Sep 25, 2007)

The external pump that came with my 300g tank is a baldor model 17E with a reeflo hammerhead pump attached. I am trying to determine its flow rate between 4-6 feet. I assume flow rate is determined by the combination of the pump and motor? I would obviously like to maximize the amount of turnover but there may be an issue with too much current in the tank if the return pump is not throttled back.

This setup was previously used as a reef tank and the previous owner said he used a ball valve to restrict return water flow as it was too much current in the main tank. Rather than a ball valve on the tank returns, could I plumb in a T right off the pump, install a ball valve, and return any "excess" water volume back to the inflow end of the sump? Wouldn't that actually increase my volume per hour of water turn-over effectively increasing my biological filtration? The 
ball valve in the T that runs back to the sump essentially would control the volume running back to the main tank.

And wouldn't having the ball valve on a direct return to the sump actually be safer in the event of a ball valve failure? If it fails, increased flow will go to the sump rather than to the main tank (which could overflow the main tank if the overflows can't handle the extra volume).

The current overflow boxes (2) have 1 hole each measuring 3" and 1.75" in the bottom pane. I am unsure of what diameter the piping would be, this is my first sump set up, obviously the larger hole is the outflow from the main tank. I think the 3" hole would house a 2" bulkhead. I am actually thinking of taking these overflow boxes out and replacing with a glass-holes #3000 http://www.glass-holes.com/3000-Overflo ... 000kit.htm . This would for give 2 3" holes with 2" bulkheads so my outflow volume shouldn't change at all. The glass-holes website states "Recommended continuous flow rates: 1000-2000gph, maximum 3000gph." I am unsure why the recommended continuous versus max flow rates are so different, I have emailed the manufacturer for clarification. At 300g, it seems recommended to shoot for 3000gph turn-over and maybe 2 - 2 inch bulkheads can't provide this?

I'm having a challenge determining how much water will flow with 2" bulkheads, numbers seem to vary GREATLY. I also understand the vertical drop (in my case close to 5 feet) and number of bends (in my case 3) increases friction, decreasing flow.

Thanks.


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## markl323 (Feb 28, 2013)

you can do the T for your return but IMO it would not be the most efficient system since you will be processing water that has just been processed. Most use a ball valve to reduce the flow and save on electricity.

the best way to prevent a sump overflow is to drill a 1/4" hole on your return U-tube, approximately 1" below the water level. then always make sure your sump has enough empty volume to handle this 1" height of main tank water.

according to this table, 2 x 2" bulkheas will handle 3000GPH.

i think the recommended flow rate has more to do with the noise level.

diameter GPH
1/2 90
3/4 220
1 375
1 1/4 580
1 1/2 840 
2 1500


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## markl323 (Feb 28, 2013)

also, your T shouldn't have to be so complicated. if you are worrying about valve failures, you can just have two ball valves in the main tank return to prevent a main tank overflow. although i think it's typically those one-way/check valves that are more prone to failure.


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## b3w4r3 (Dec 14, 2012)

Not familiar with that pump so hopefully you can find the turnover rate for your head pressure. An option would be to run two return lines to the tank. That would increase head pressure and help spread the flow better.

Don't get too hung up on turnover rates. A wet dry is a lot more efficient that the typical canisters people around here are using so 10x turnover is not going to be necessary. Plus most people think they have more turnover than they really do. The majority of canisters rarely produce over 50% of their advertised flow rating with the media installed and hoses running to the top of the tank.

Without knowing the working pressure of the pump it's hard to give advice on whether your bulkheads will be large enough. But again adding more return lines, and going with larger diameter return hoses will increase head pressure without the need of any ball valves.

Best thing to do is wet test the setup, and see how things play out.


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## chiroken (Sep 25, 2007)

So I've tracked down the head pressure/gph for the pump I have. It is 5,500 @ 4' and 4,880 @ 9'. I'm looking at 5' or just shy with my tank set up. That'll put me at maybe 5,300gph give or take. Guess that's why the previous owner had it throttled back.

I will definitely have 2 returns to the tank as it is an 8 footer. There will be a T on the return to split the return water into 2 (I guess a Y would be less restrictive?). I am undecided on the diameter of the returns and then I may reduce it to 3/4 locline with a flared nozzle or run returns and end each return to a DIY spray bar. I have the previous plumbing (in pieces) and he ran 1 1/2 out of the pump, took it horizontal, then went vertical for each return and reduced to 1". Each return had 3/4 locline in the tank. All using T's, no Y's.

If I go with the glass-holes box I thought I would mount it centred on the back wall. If I brought each return in on the back corners, I thought I could run spray bars along the back wall towards the overflow box. I assume this would create a circular water flow from spray bar (back surface) -front surface - down the front glass- back towards the rear of the tank in the lower levels. If this was the current that was established I assume there would be less accumulation of "dirt" in the front of the tank. Bonus for that!

mark: you mention drilling a hole in the returns, within the tank. If the end of the returns in the tank are not below the lowest level of the teeth in the overflow box, this hole would not be necessary, correct? It would syphon break itself as the water level would drain to the level of the overflow box. I may not be able to drill the return bulkheads above the lowest point of the overflow teeth (too close to top edge of tank glass?) but as long as I pay attention to where the return actually ends in the water column that is key, correct? I guess locline can be bumped but a spray bar would be in more of a fixed position.

Thanks for the suggestions/info, this needs to be done right the 1st time!


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## markl323 (Feb 28, 2013)

you are correct. there's no need to drill a hole if the opening of the return is above the lowest end of your overflow box.

I use a Y too instead of a T. although I don't think it makes any difference in flow rate or noise since this part of the plumbing will be very quiet. the noisy part is plumbing going from your overflow box to your Wet/Dry chamber.

BTW that pump is an overkill for your tank IMO. before you glue everything together i would do a test run with a tank full of water and see how much heat it puts out (if it uses water instead of a fan to cool itself). even my Mag Drive 9.5 added 2F to my 180G tank.


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## chiroken (Sep 25, 2007)

markl323 said:


> BTW that pump is an overkill for your tank IMO. before you glue everything together i would do a test run with a tank full of water and see how much heat it puts out (if it uses water instead of a fan to cool itself). even my Mag Drive 9.5 added 2F to my 180G tank.


I doubt it matters but I should mention this will not be a wet/dry sump, strictly wet (that's how it has been built). Now that I say that, when the sump actually gets to being functional I am going to look to see if there is enough vertical clearance to add some sort of drip tray/wet/dry section over the 1st sump portion where the water originally enters the sump tank. Not sure if there is or not.

I agree this is overkill but that's the pump the previous owner used so i see no need to spend hundreds of dollars to replace it. At some point down the road (hopefully many yrs!) it will fail and I'll replace it.

This pump is external and the pump is separate from the motor (bolted to the end of the motor) so I doubt motor heat will affect the water temperature at all. I know what you mean though, I had a heater element go in my outdoor hottub (mild Canadian climate). My water temp was 98^ and the store told me this was heat from the still running motor. I didn't believe them until the element was replaced and the temp went back up over 100^ 

I also forgot to follow up on a comment you made before "you will be processing water that has just been processed".An important question is will 100% of ammonia and nitrite be processed with a single pass through the sump? That would be determined by the amount of bacterial colonization. I assumed it isn't completely processed with a single pass (100% efficient). By circulating water directly back through the sump I assume it would further process nitrogen compounds. If there is additional biological filtration by passing the water directly back through the sump it seems like a wasted opportunity to throttle back the outflow rather than moving that "extra" water back into the sump. Thoughts on this?


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## markl323 (Feb 28, 2013)

bacteria live on the hard surface of bio-media. waste products only get remove if they hit the bacteria. imagine clean water hitting the surface (because it had been processed earlier).

you want a Wet/Dry for freshwater. Wet (Berlin) only setup only works with saltwater where you don't want to convert waste to nitrate so your protein skimmer can remove them from the water and any little nitrate left can be effectively removed by a small chunk of macro algae.


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## chiroken (Sep 25, 2007)

markl323 said:


> you want a Wet/Dry for freshwater. Wet (Berlin) only setup only works with saltwater where you don't want to convert waste to nitrate so your protein skimmer can remove them from the water and any little nitrate left can be effectively removed by a small chunk of macro algae.


Would you mind clarifying this? I've read countless threads where people are using wet sumps for freshwater with either matting or bioballs ect submerged. Everything I've read says wet/dry is more efficient (only when set up correctly) due to increased oxygenation but I've never read a wet sump doesn't work in freshwater.

Thanks


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## b3w4r3 (Dec 14, 2012)

A wet bio section will work fine, and even in a saltwater Berlin system the live rock handles the bulk of the nitrogen conversion and it is certainly submerged. It's important to note that the same number of bio balls that works in a wet dry won't work as well submerged. There are much better choices for submerged media that take up a lot less space.


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## chiroken (Sep 25, 2007)

b3w4r3 said:


> It's important to note that the same number of bio balls that works in a wet dry won't work as well submerged. There are much better choices for submerged media that take up a lot less space.


Your first sentence, this is due to increased oxygenation in a wet/dry so more efficiency per gallon of bio balls, correct?

Better choices for submerged media would be? My current set up, as the previous owner had it, used I believe matala mats in vertical orientation within baffles. I am also looking to add more bio material (more matting?) in horizontal positions. Budget is a concern and I'm hoping I can get away with perhaps less costly bio media due to the size of my sump (meaning I can just use more media). The sump is a 6 footer for an 8 foot tank.


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## b3w4r3 (Dec 14, 2012)

With that much space and knowing your return pump is over sized it might be worth looking into Kaldnes k1/k3 media. You could use one line from the pump to to keep the media suspended. It's definitely a trial and error DIY thing, but has a lot of the benefits of a fluidized sand filter without the troubles. Seachem Matrix is another option which could work well submerged.


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## chiroken (Sep 25, 2007)

b3w4r3 said:


> With that much space and knowing your return pump is over sized it might be worth looking into Kaldnes k1/k3 media. You could use one line from the pump to to keep the media suspended. It's definitely a trial and error DIY thing, but has a lot of the benefits of a fluidized sand filter without the troubles. Seachem Matrix is another option which could work well submerged.


I had looked into Kaldness but I thought it needs to run off air pumps and I didn't want to add more equipment costs to the system. Are you saying I can T off the return (before it T's to go to each of 2 returns I'll have) and run a line back into the compartment that houses the K1 and that water circulation will keep the K1 always on the move? An inline shut off valve would determine flow into the K1? And how would that water be added to the k1, via a spray bar or something? And remembering I have 2 chambers available, 10"x22" & 20"x22", each only 12" high, based on the current baffle configuration.


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## b3w4r3 (Dec 14, 2012)

You don't need air bubbles, just need to have enough flow to keep the media tumbling. Something on the top would be needed to keep the Kaldnes from leaving the chamber, maybe a piece of poret foam. I think just running a line from the pump into the chamber discharging near the bottom would create a nice circular flow. Water from the tank would overflow into the chamber after being pre filtered and mix with the water from the pump. Not sure how the baffles are set up, and some water would be recirculated through the bio section. That's not a bad thing though. I think only one of the chambers would be necessary depending on how much media can be used and still circulate well. It's just an idea though, I have never used this stuff, but I believe it can work well.


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## lilscoots (Mar 13, 2012)

You may be past this already, but you'd be fine just running a T with a ball valve back into the sump to control the flow into the main tank. You could utilize that flow in a Fluidized bed or what not or you could just pipe it right back into the sump. Also, many people use wet systems and they work fine, especially with a tank with that amount of water surface you have (tank and sump), as long as you keep the surface moving, oxygen will not be a limiting factor for your bacteria or your fish. As far as media, I use ceramic rings (matrix/biomax) and poret foam in my sumps (wet).


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## chiroken (Sep 25, 2007)

I will have to put (more) serious thought in how I set this up. I'd like to not move baffles if I don't have to however if it makes a major difference then I'm OK to do that.


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## lilscoots (Mar 13, 2012)

I wouldn't move any baffles, You could always put foam and filter floss horizontal in after the first baffle (in the 10" section) for mechanical and some bio filtering and put some ceramic media or pot scrubbies or whatever wet media you like in the 20" section, you could even grow plants or something. You shouldn't have to move any of those baffles.


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## chiroken (Sep 25, 2007)

lilscoots said:


> I wouldn't move any baffles, You could always put foam and filter floss horizontal in after the first baffle (in the 10" section) for mechanical and some bio filtering and put some ceramic media or pot scrubbies or whatever wet media you like in the 20" section, you could even grow plants or something. You shouldn't have to move any of those baffles.


I was thinking of horizontal media in the 1st 10" section. I was toying with the idea of rigging up an eggcrate tray in the 20" section to have pothos plant cuttings it, just for fun. Was thinking to leave this section basically clear to use as a short term rehab area if a fish needs some down time.


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## lilscoots (Mar 13, 2012)

chiroken said:


> I was toying with the idea of rigging up an eggcrate tray in the 20" section to have pothos plant cuttings it, just for fun. Was thinking to leave this section basically clear to use as a short term rehab area if a fish needs some down time.


You read my mind it seems on the refuge part, though that amount of water volume running through there may have a bit of a strong current? maybe not.


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## chiroken (Sep 25, 2007)

lilscoots said:


> chiroken said:
> 
> 
> > I was toying with the idea of rigging up an eggcrate tray in the 20" section to have pothos plant cuttings it, just for fun. Was thinking to leave this section basically clear to use as a short term rehab area if a fish needs some down time.
> ...


At first I thought you meant strong current for the plants but I never thought about for the fish. You are probably right, if I can move 2000+gph that is alot moving through a small space. That'll leave more bio media space but at what point is it too much???


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## 1971ls6 (Oct 29, 2012)

I have about 3 gallons of k1 media that I bought to play with the fluidized bed filters, I think for big tanks the stuff is a must. I will sell it cheap if somebody wants it.

[email protected]


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