Return pump replacement

[trying4corals]

Hi, I am new to the hobbies and not entirely sure where to look for a new return pump for my system. The current pump is a 1 hp inline pump, that the tank build company installed when they installed my tank, and it is putting off way to much heat. I have a 700 gallon display tank with a 300 gallon sump tank. I want to replace the pump to one that is quite and puts off less heat, the current pump is heating my water up to above 80 and killing all of my clean up crew members, corals, macro algae and stressing my fish out. I do have 2 chillers and they aren't able to keep up with how warm this pump is making my water. Any help would be greatly appreciated. Thank you.

 

[UncommonSense]

Have you looked into “Abyzz” brand pumps at all?

They aren’t cheap, but they will likely have pump models which suit your needs here!

 

[trying4corals]

Have you looked into “Abyzz” brand pumps at all?

They aren’t cheap, but they will likely have pump models which suit your needs here!

I will look into them, if they dont produce the heat that my current pump produces, I do not mind paying the cost. Thank you for the suggestion.

 

[UncommonSense]

I will look into them, if they dont produce the heat that my current pump produces, I do not mind paying the cost. Thank you for the suggestion.

Of course!

It’s also worth noting that other components of the system could merit examination to help mitigate heat issues…

— The easy first step is ensuring that heater(s) aren’t stuck on 24/7! (mechanical or electrical fault)

— from there, we get into more specific things, like your return pump’s heat generation, for example… Are there any significant restrictions to the return pump plumbing, either before, or after the pump? (Restriction creates artificial head pressure, making the pump work harder!)

 

[trying4corals]

I will look into them, if they dont produce the heat that my current pump produces, I do not mind paying the cost. Thank you for the suggestion.

Of course!

It’s also worth noting that other components of the system could merit examination to help mitigate heat issues…

— The easy first step is ensuring that heater(s) aren’t stuck on 24/7! (mechanical or electrical fault)

— from there, we get into more specific things, like your return pump’s heat generation, for example… Are there any significant restrictions to the return pump plumbing, either before, or after the pump? (Restriction creates artificial head pressure, making the pump work harder!)

The current pump should have a 2" line, however the installation company dropped it to a 1.5" line. I know this is partly reason why it is running so hot, but short of rerunning the entire plumbing system there isn't much I can do. Other then replace the pump with a pump that is made to run in a 1.5" line.

 

[mcarroll]

Hi, I am new to the hobbies and not entirely sure where to look for a new return pump for my system. The current pump is a 1 hp inline pump, that the tank build company installed when they installed my tank, and it is putting off way to much heat. I have a 700 gallon display tank with a 300 gallon sump tank. I want to replace the pump to one that is quite and puts off less heat, the current pump is heating my water up to above 80 and killing all of my clean up crew members, corals, macro algae and stressing my fish out. I do have 2 chillers and they aren't able to keep up with how warm this pump is making my water. Any help would be greatly appreciated. Thank you.

If that is a tropical reef tank, 80ºF water isn't killing your cleanup crew.

Can you tell us what the brand and model of the current pump is? A pic of the installation may be helpful.

Also, why does your tank need chillers – are you still running high-power lighting (eg halides or T5HO)?

A little more info an I could recommend a pump....but without knowing what you have now, it's hard to recommend something "better".

 

[mcarroll]

The current pump should have a 2" line, however the installation company dropped it to a 1.5" line. I know this is partly reason why it is running so hot, but short of rerunning the entire plumbing system there isn't much I can do. Other then replace the pump with a pump that is made to run in a 1.5" line.

Depending on some other factors, that could definitely be a big deal.....1HP could indicate a massive amount of flow.

But making some assumptions, a 1 HP pump I see gives 2700 GPH @ 6'....10 feet of 1.5" line only adds an additional +1 feet of head pressure or so....not really that much. Might knock actual flow down to 2500 GPH.

None of this should make a pump or system overheat.

If you noticed an increase of system temperature, I agree with searching for other causes.

 

[trying4corals]

Hi, I am new to the hobbies and not entirely sure where to look for a new return pump for my system. The current pump is a 1 hp inline pump, that the tank build company installed when they installed my tank, and it is putting off way to much heat. I have a 700 gallon display tank with a 300 gallon sump tank. I want to replace the pump to one that is quite and puts off less heat, the current pump is heating my water up to above 80 and killing all of my clean up crew members, corals, macro algae and stressing my fish out. I do have 2 chillers and they aren't able to keep up with how warm this pump is making my water. Any help would be greatly appreciated. Thank you.

If that is a tropical reef tank, 80ºF water isn't killing your cleanup crew.

Can you tell us what the brand and model of the current pump is? A pic of the installation may be helpful.

Also, why does your tank need chillers – are you still running high-power lighting (eg halides or T5HO)?

A little more info an I could recommend a pump....but without knowing what you have now, it's hard to recommend something "better".

Current pump

 

[trying4corals]

Hi, I am new to the hobbies and not entirely sure where to look for a new return pump for my system. The current pump is a 1 hp inline pump, that the tank build company installed when they installed my tank, and it is putting off way to much heat. I have a 700 gallon display tank with a 300 gallon sump tank. I want to replace the pump to one that is quite and puts off less heat, the current pump is heating my water up to above 80 and killing all of my clean up crew members, corals, macro algae and stressing my fish out. I do have 2 chillers and they aren't able to keep up with how warm this pump is making my water. Any help would be greatly appreciated. Thank you.

If that is a tropical reef tank, 80ºF water isn't killing your cleanup crew.

Can you tell us what the brand and model of the current pump is? A pic of the installation may be helpful.

Also, why does your tank need chillers – are you still running high-power lighting (eg halides or T5HO)?

A little more info an I could recommend a pump....but without knowing what you have now, it's hard to recommend something "better".

This is my current sump set up, the current pump is a duamond aqua sea 7450.

 

[mcarroll]

Dolphin specs 1.5" plumbing for that BTW. Also, the 1HP is the 9250 model – you have the 3/4 HP.
https://dolphinpumps.com/aqua-sea
Unless something is seriously broken, that pump is not heating your tank....the motor should be the only thing that gets hot and it doesn't touch the water. (That's one of the specific advantages of this type of pump.)

Have you taken the pump apart for a basic cleaning? Depending on its age and history it could be in need! :)

And BTW Dolphin pumps are awesome....some of the best made. I wouldn't switch. Call them if you have any issues/questions.

Out of curiosity, what's the air temperature in that sump room?

 

[dank.reefer]

I am a little late here and hope you have already found your issue. First I will say that 80 isn't bad and is not likely what is killing your live stock. I run my tanks at 80 in the summer time to keep them more stable and save on the energy costs of cooling them. I couldn't help but notice the 2 large water chillers you have in the sump room. What do you have for air flow in there? I ended up getting rid of my chiller in the garage because it was more of a problem than a help. The chiller would come on and cool the tank but it would also heat the room. Eventually the room was so hot that the chiller never shut off. I found it to be much more efficient to just air condition the space.

 

[exnisstech]

Dump and run. OP hasn't been back since the question was posted

 

[BryanM]

weird too, there is clearly a serious investment here. But yeah, the way that pump sits its hard to imagine it adding any heat.

 

[dank.reefer]

weird too, there is clearly a serious investment here. But yeah, the way that pump sits its hard to imagine it adding any heat.

Yeah I was impressed by the setup considering the OP had stated that he is new to the hobby.

 

[Pntbll687]

This is my current sump set up, the current pump is a duamond aqua sea 7450.

Ok, so a couple of things.

The return pump is probably adding minimal heat to the system. The motor may get warm, but the water doesn't touch the water so only a minimal amount of heat will be transferred.

Those two chillers are probably not doing much of anything to cool the system. The ventswhere the hot exhaust air comes from are backed up against a wall, so the chiller is going to have to run for a long time, and all that hot air is being right back into the room and water in the sump.

If a company installed all this for you and is helping maintain the tank, RUN as far away from them as possible. Power strips dangling from pvc pipe by the return pump, outlets being used directly above an open section of the sump and next to the skimmer, because you know skimmers never foam over or have any salt spray that escapes them. Chiller installed without a vent for the hot air. Lights sitting on top of the sump (i'm guessing for a refugium) with nothing holding them up or mount of any kind. Fernco fittings being used for no visible reason other than they ran out of the correct size pipe and wanted to get it done anyway possible. I'm actually scratching my head trying to figure out what those fernco fitting and Y accomplish. Is it to drain water back to the sump if you close the valve for the return pump to service it? Because any extra water would just drain back through the normal drain lines anyway.

But as for your question on return pump, an abyzz is ideal, but cost is high. The Reef Octopus Varios 10 is another great option. it has 1.5in inlet and 1.25in outlet, so it would need a minimal amount of pipe work to fit onto your system.

 

[BeanAnimal]

The current pump should have a 2" line, however the installation company dropped it to a 1.5" line. I know this is partly reason why it is running so hot, but short of rerunning the entire plumbing system there isn't much I can do. Other then replace the pump with a pump that is made to run in a 1.5" line.

The line size is not causing the heating -- without getting into the physics a watt is a watt and depending on pump style, that heat is shed into the water and into the room at some ratio. Submerged pumps shed all of their heat into the water. Traditional centrifugal pumps with a motor and shaft driven volute shed most of their heat into the room. Magnetic drive pumps runs externally shed a predominant amount of their heat into the water.

While some pumps styles are slightly more efficient than others, they are all going to be in the same ballpark when talking about large, high quality aquarium pumps.

As noted above, your pump is a standard shaft driven centrifugal pump.

If sized properly, very little of the heat generated enters the water directly. If vastly oversized, there is friction in the volute dues to the output being restricted by head pressure. That said, the contribution difference is likely minimal in this case.

80F should not be killing inverts. So you may have another issue.

Regarding heat - I don't think you are going to gain anything by moving to a large DC or other magnetic impeller pump (internal or external) , and will likely put more heat into the water.

Given that your system is steady state near the top end of the heat envelope, I would seriously consider evaporative cooling (fans). The downside is humidity and increased top off.

If this is not acceptable, then lower the room temperature will help.

In the end, the best advice however is going to be incorporating a proper sized chiller and removing the heat from the room. Either via an HRV or ERV or using a minisplit to cool the room.

What size are the current chillers? Sorry if I missed it in the thread.

 

[bushdoc]

I had 240gal system years ago with external pumps and yes they were generating heat, so I eventually changed to DC pump with lower wattage. Your pump is rated 400-500w, additionally you are running water through long pipes which also generate some heat due to friction. How much does it contribute to increasing your tank temp is uncertain though.
But you should also consider other sources of heat like lights (do you have LEDs or different type of light?), I would also think about ventilating sump/pump room ( I had a thermostatic fan in my pump/sump room).
Abyzz is a DC pump with lower wattage than corresponding AC pumps, so it's worth while considering as it would save you some bucks on electricity bill.
I would also look through Mega Built tanks thread to see what setup other people have.

 

[BeanAnimal]

I had 240gal system years ago with external pumps and yes they were generating heat, so I eventually changed to DC pump with lower wattage. Your pump is rated 400-500w, additionally you are running water through long pipes which also generate some heat due to friction. How much does it contribute to increasing your tank temp is uncertain though.

The heat generated in the piping is minimal. A watt is a watt, so all 400W ends up as heat in the room or the tank one way or the other. Be it "friction" in the piping or literal water movement in the tank. You can't cheat the physics.

Your DC pump of lower wattage produced lower heat.

Abyzz is a DC pump with lower wattage than corresponding AC pumps, so it's worth while considering as it would save you some bucks on electricity bill.

AC induction (PSC) motors lose some efficiency due to slip, rotor losses, and bearing friction, but they use line voltage and frequency directly, with no conversion losses.

Also, this is a residential setting and residential meters measure real power (watts), not reactive power, so you aren’t billed for the power factor component. If these were giant industrial pumps at a factory, then the lagging power factor losses would play a role.


Brushless DC pumps can achieve slightly higher motor efficiency through better electronic phase control, but they incur conversion losses in both the AC to DC power supply and the inverter transistors that generate the three phase output to the motor. For hobby grade equipment, these losses are easily 10%-20% or more. For commercial equipment, they may be lower than 10%. I think you will find that Abyzz has had some issues with power supply and driver heating issues, but I don't know their overall efficiency.

While a BLDC motor and controller typically run at unity power factor, the PF savings only comes into play with large industrial customer.

BLDC pumps are attractive for several reasons, but mostly because they don't lose efficiency when speed controlled. So BEP (Best Operating Point) is not a fixed point like it is with a PSC drive pump.

So in the end, there are not great electric or heat savings for most users who switch to DC pumps, unless of course they are moving less water. To that end, many of the flow ratings on pumps sold to this hobby are ridiculously inflated.