Return Pumps - AC vs DC

[RoanokeReef]

Morning all! Looking at purchasing a new return pump. It seems most go with DC pumps now but wondering if I might be better served with an AC pump. I currently have a Neptune COR 15 I'm at my wits end with. It gradually slows down over the course of usage until I take it apart and clean it or my water level is constantly changing. However, it's never dirty besides a little bit of film and I have to go through this same routine every two weeks. I have swapped the motor block and driver for new. My tank is a 69g so any recommendations would be great. I have a spare NYOS Vipre pump I'm thinking of using. Now to be clear I know all pumps need to be cleaned but every two weeks seems a bit much, in the past I've always used AC pumps and clean them once every 3 months.

 

[magikfly]

DC use less electricity and have adjustable speed. That alone makes them the best option IMO

 

[RoanokeReef]

DC use less electricity and have adjustable speed. That alone makes them the best option IMO

I'm currently using 42W according to Apex and the Vipre is listed as 31.5w. Outside of feed modes what benefit does adjustability provide?

 

[Kodski]

I'm currently using 42W according to Apex and the Vipre is listed as 31.5w. Outside of feed modes what benefit does adjustability provide?

It allows you to dial in your overflow much easier. Especially when your pump gets dirty and starts to loose flow rate, I usually just increase the pump's power by a notch or two and I don't have to futz with the ball valve on my overflow. Then when I clean the pump regularly, I just put the power back down to where I usually have it.

Also the noise difference. DC will always be much quieter than AC pumps because of the technology they use. I don't care if your AC pump is "quiet" the DC pump will always win out in a noise comparison.

Edit: Just reread your OP and see that you're having issue. That to me sounds like either a driver issue with the pump or a plumbing issue somewhere. Have you checked your plumbing to ensure there is no algae or other things growing causing a blockage? Your wattage being used shouldn't exceed the pumps rating, that's a huge red flag.

 

[mcarroll]

Morning all! Looking at purchasing a new return pump. It seems most go with DC pumps now but wondering if I might be better served with an AC pump.

Most folks would be IMO. Once the cheerleading on DC pumps started, it was uncontainable. :D

I don't think most of us know enough about them to know they are MOSTLY THE SAME PUMP.

Someone smarter than me wrote this article about it....a really good read.

I currently have a Neptune COR 15 I'm at my wits end with. It gradually slows down over the course of usage until I take it apart and clean it or my water level is constantly changing. However, it's never dirty besides a little bit of film and I have to go through this same routine every two weeks.

I'm with you that 2 weeks is a REALLY short timeframe.

I wonder if you are measuring actual flow directly or if you might be going off of a computed GPH value somewhere on your automation?

Before making any big changes (assuming you haven't done this already) I recommend measuring actual GPH yourself, either at the return outlet(s) or at the drain. A 1 quart measuring container is often convenient, time how long it takes to fill up.

Also, that seems to be a MUCH MUCH MUCH larger pump than the Viper you're thinking about replacing it with....any reason you're using such a gi-normous pump on this tank?

$99 vs $475 too....are you sure you're using the right pump, or is that the smallest one they sell or something? Holy $moke$!

What size is the plumbing on your return pipes?

My tank is a 69g so any recommendations would be great. I have a spare NYOS Vipre pump I'm thinking of using. Now to be clear I know all pumps need to be cleaned but every two weeks seems a bit much, in the past I've always used AC pumps and clean them once every 3 months.

Guessing you are referring to the Viper 2.0....seems to match your power stats. Sell that COR and buy a backup return pump with some of the funds.....then throw yourself a party with the rest. :)

NYOS doesn't seem to supply a performance curve so we can't really predict what your flow rate would be, but IMO it's the right size of pump to try base on your tank size.....target flow rate "should be" somewhere around 300-350 GPH. Do the same measurement trick above to see what this pump delivers once it's installed.

Every 3 months should be fine in most situations.

I'm currently using 42W according to Apex and the Vipre is listed as 31.5w. Outside of feed modes what benefit does adjustability provide?

The COR 15 uses up to 50 watts according to Neptune, which seems like it should be a ton of flow for a tank this size. Strangely (especially for the price category) it seems you don't even get a flow curve for the COR 15....only the COR 20 seems to be on their website.

Anyway, that limits the discussion a lot. But a pump that large, set that high SHOULD BE putting out a whole other class of flow than the Nyos 2.0 is capable of....maybe >1000 GPH.

Seems like that flow (and that pump) should be massive overkill for a tank this size, so the switchover to the Nyos should work well IMO...see what the difference is in power usage after the switch as well.

Might be worth pointing out for the discussion that if you have to throttle back the Nyos 2.0, it consumes as little as 12 watts at its lowest output. I suspect it'll be fine at max flow, but measure it once it's installed as already mentioned.

 

[RoanokeReef]

I actually have the NYOS 2.0 already as I was going to originally going to use it, I got the COR due to being heavily invested in the Apex system. Has a lot of nice fail safes and alerts. I have no problem with the flow per se, the issue is after cleaning (2600RPM) within a couple weeks it will slow down (2500RPM) which in turn makes the water level go out of whack in the sump, tank, and overflow. When this happens if I take it out and wipe down the impeller (which doesn't show any, too little "dirt" and reinstall its back at 2600RPM again. The only thing I haven't tried which I might before switching to another pump is install in into my other Energy Bar to eliminate the last thing I can think of.

Edit -
The Plumbing
Primary Drain: 32mm
Emergency Drain: 20mm
Return Plumbing: 20mm

Second Edit -
I probably should have worded it better in my OP but after being in this hobby for 15+ years this was my first DC return, so I didn't know if DC pumps are just more susceptible to slowing down from bio film and such vs AC and maybe having to clean a return every two weeks was a norm with these pumps.

 

[mcarroll]

I probably should have worded it better in my OP but after being in this hobby for 15+ years this was my first DC return, so I didn't know if DC pumps are just more susceptible to slowing down from bio film and such vs AC and maybe having to clean a return every two weeks was a norm with these pumps.

There are some "if's" that might explain that...

If the pump is engineered "too efficiently" to get some marketing number "higher than the rest", then it's conceivable that a biofilm will start to occupy space in the housing where the impeller and water belong and it will actually have a negative effect on the throughput.

Every pump is a design compromise, and most pumps allow plenty of inefficiency so there's extra room for debris to pass through the pump without making a big impact on performance.

Trash pumps like this allow A LOT of inefficiency:

Pumps that build a lot of pressure are likely to have much closer tolerances.

Most pumps we use fall somewhere in the middle and are pretty tolerant of biofilms, etc....but you could have an outlier. Seems like it should be unlikely, but it's possible something like that is going on with this pump.

It would be interesting to see if a pre filter made any difference...but wouldn't change my opinion that 2 weeks it still too short a maintenance cycle....if this is normal I think I'd select a different pump.

 

[RoanokeReef]

Wanted to update this - Switched the 1Link cable to my second EB832 and so far, it has held the RPMs since the 23rd. Fingers crossed.

 

[BryanM]

Yeah, I'm not sure why it would slow down like that without some other issue. I hope that cable swap helps, although that seems odd to me as well.

I have a cor-20, its only using 20 watts. Never cleaned, don't adjust... it just works.

 

[Dr. D]

DC for the win!

 

[kdx7214]

I use a Hygger 2160gph DC pump for my return and it works flawlessly. The first one lasted a bit over 3 years. Bought a replacement for $120 and it fit perfectly. It runs 65w at full power and you can adjust it down easily. I'll never go back to an AC pump.

 

[Sean Clark]

All of the energy that goes into my AC pump gets used to heat the tank. I call that a win.

 

[painter1982]

I just switched from a sicce “silent” ac pump to a sicce dc pump. I wouldn’t go back for anything. The silent pump was so loud. It’s one of those noises you learn to tune out but once it’s gone it’s very noticeable. The dc is adjustable so it was easy to make my overflow silent.

 

[mcarroll]

The first one lasted a bit over 3 years.

False economy if you break it down.

Most major brands would call 3 years a defect (5 year warranty isn't uncommon) and warranty you out of that situation. (Tho a major pump might not have failed at all.)

A similar wattage Mag is about the same cost up front....$150-ish. After a warranty issue you're still only at $150.

You're into Hyggr for $240 now. Maybe $360 if it breaks again. (Looks like three years is their warranty period.....highly engineered, that's without doubt.)

 

[dinosaur_1552]

DC every time, noise levels and less volts in tank in case something goes terribly wrong.

 

[Freenow54]

Morning all! Looking at purchasing a new return pump. It seems most go with DC pumps now but wondering if I might be better served with an AC pump. I currently have a Neptune COR 15 I'm at my wits end with. It gradually slows down over the course of usage until I take it apart and clean it or my water level is constantly changing. However, it's never dirty besides a little bit of film and I have to go through this same routine every two weeks. I have swapped the motor block and driver for new. My tank is a 69g so any recommendations would be great. I have a spare NYOS Vipre pump I'm thinking of using. Now to be clear I know all pumps need to be cleaned but every two weeks seems a bit much, in the past I've always used AC pumps and clean them once every 3 months.

I like DC a Vortex ? However I put a simple sponge filter around the return pipe in the sump I cant believe hoe clogged it gets in the course of 2 months but easy fix