Help / Opinion please on return pump flow range and GPH

[XLReefer525]

Opinions please! Forget about head loss for the moment and please help me understand this. I have a Sicce Syncra SDC 7.0 return pump which is a DC adjustable pump with an advertised flow range of 800-1900 GPH. If I run this pump at 50%, am I running 950 GPH (1900 highest speed x 50%), or am I running 550 GPH (1900 highest speed minus 800 lowest speed = 1100 x 50%). If it's the first one, then that would be higher than the advertised lowest GPH. Anyone??

 

[blaxsun]

950Gph. If you run it @10% it’s approximately 190Gph, minus vertical height, elbows, etc. If you go to Sicce’s website and look up the SDC pumps they have performance charts that show what the maximum output in Gph will be based on head loss.

 

[Montiman]

I think you are way over thinking this.

If this is a return pump I would just plug in the pump and run it at max power. if your drains can't handle it then you over bought the pump. I don't want a pump with a "flood my tank" setting.

The exact GPH has virtually no relevance except for with a UV sterilizer. If you are trying to dial the flow for a UV don't overthink that either. In most cases a return pump at max flow is just about right for a UV algae kill rate but you will need a lower flow for parasite control.

 

[nereefpat]

I seriously doubt that the ratio between the control % and gph is exactly linear.

I would guess your second option is closer to correct, but then a DC pump with head pressure will be nowhere near that high.

I agree with just running the pump, and finding a flow that you like through the sump that your overflow can safely and quietly handle.

 

[XLReefer525]

Thanks for the replies and again, ignore head loss for a moment. What I asked about running at 50% was just an example. I'd really like to know what the answer is. I sent an email to Sicce but have not heard back. I mean why have 800 GPH as the lowest end of the flow range if it can go down to almost zero?

 

[Pistondog]

Opinions please! Forget about head loss for the moment and please help me understand this. I have a Sicce Syncra SDC 7.0 return pump which is a DC adjustable pump with an advertised flow range of 800-1900 GPH. If I run this pump at 50%, am I running 950 GPH (1900 highest speed x 50%), or am I running 550 GPH (1900 highest speed minus 800 lowest speed = 1100 x 50%). If it's the first one, then that would be higher than the advertised lowest GPH. Anyone??

If it's easy, put the return pump hose into a 5 gallon bucket and see how long it takes to fill. If it takes a minute, 300 gph. If it takes 30 seconds, 600 gph.
Approximate the actual height if possible.

 

[KStatefan]

Thanks for the replies and again, ignore head loss for a moment. What I asked about running at 50% was just an example. I'd really like to know what the answer is. I sent an email to Sicce but have not heard back. I mean why have 800 GPH as the lowest end of the flow range if it can go down to almost zero?

800 gph is the flow at zero head at the minimum speed.

 

[blaxsun]

800 gph is the flow at zero head at the minimum speed.

The minimum speed is 1-3%, and I guarantee it’s not 800Gph. I have the SDC 6.0 and 9.0 and you can run them at a trickle if you choose to (useful when feeding).

There are reasons and scenarios where you may not want to run a pump @100%, ie: where the return flow is sandblasting your corals, turning the tank into a snow globe or causing your fish to flee for their lives.

 

[outhouse]

im running my DC pump at 45% to save wattage and have quiet flow. anything over 700 is way too much for a return pump. Run as low as you want and keep your AC bill down, and have a quiet tank. 1000gph would be ridiculous

 

[blaxsun]

im running my DC pump at 45% to save wattage and have quiet flow. anything over 700 is way too much for a return pump. Run as low as you want and keep your AC bill down, and have a quiet tank. 1000gph would be ridiculous

My Sicce 9.0 delivers around 750-800Gph @45% rated @2500Gph), but this is on a 200-gallon system (160-gallon display). So that’s on the higher end of the 3-5x hourly tank turnover.

 

[outhouse]

My Sicce 9.0 delivers around 750-800Gph @45% rated @2500Gph), but this is on a 200-gallon system (160-gallon display). So that’s on the higher end of the 3-5x hourly tank turnover.

My Jebao 10000 is almost an identical flow pump, and lol im running it just like you at that same exact rate, I have a 210g tank and a basement 100g sump so maybe 270 actual water volume. Its nice having a quiet tank. More then enough for a skimmer and a heater and ATO and kalk/ ca reactors

 

[outhouse]

Anyone??

So in a perfect world you would get 950 at 50%. but besides head height you also have tube or pipe diameter that can reduce flow. In the real world your not going to get 950gph at 50% with that small of a pump. I ran as much 1 1/4 pvc as I could. and ran a T with 1" on either side and made a Y instead of a T to run my 2 outputs, which go down to 3/4 through the tank. It takes a few tricks to keep flow at its highest ratings

 

[workhz]

When I spoke with the tunze rep, he specifically stated that the control was more linear between 30-70%. The stuff at the bottom end and top end were all over the place.

I’m pretty sure that math for 50% is the middle of the range. So if it says 500-1000gph, 50% would be 750.

Whoever said you can slow it down to a trickle, was that level with the pump or going up a few feet?

 

[blaxsun]

When I spoke with the tunze rep, he specifically stated that the control was more linear between 30-70%. The stuff at the bottom end and top end were all over the place.

I’m pretty sure that math for 50% is the middle of the range. So if it says 500-1000gph, 50% would be 750.

Whoever said you can slow it down to a trickle, was that level with the pump or going up a few feet?

That could very well be - I’ve never measured it. When my Sicce SDC 9.0 drops to 5%, it’s barely enough to keep water flowing into the overflow (the water level in the display drops quite a bit).

In any event, if one is really obsessed with the flow rate something like Neptune’s flow sensor is probably the way to go. At the end of the day (speaking only for my tank) I really don’t care. I have an approximate idea, the fish and corals are happy and I’m not dumping a cup of substrate out of my sock filters every week.

 

[KStatefan]

The minimum speed is 1-3%, and I guarantee it’s not 800Gph. I have the SDC 6.0 and 9.0 and you can run them at a trickle if you choose to (useful when feeding).

There are reasons and scenarios where you may not want to run a pump @100%, ie: where the return flow is sandblasting your corals, turning the tank into a snow globe or causing your fish to flee for their lives.

I miss understood the specs then I do not have one yet.

I read this chart to mean that at the min wattage 20 the the max flow a 0 head was 800 and the max head height was 6.5 ft.

 

[Dweezilz]

I'm a year late to this post but I'm having a problem with water level stability in my overflow with my Sicce Syncra SDC 6.0 in my Reefer 250 V1 after upgrading from my super steady but 7 year old Eheim. My level is going up & down all day and then way down or way up etc... Without my ATO it stays for a stable for a day or two but if I turn on my ATO, my system simply can't adjust when water is added. After reading dozens of posts that don't seem to help, I called Sicce and figured the information could be helpful to someone with this issue even if a year after the OG post.

Sicce said that absolutely the power level is a percentage of the RANGE not the total (before head loss). Similar to what the Tunze rep told someone who posted previously, the pump will not be stable long term with anything under 30% and they recommend 40% for a daily setting in order to maintain a proper stable water level in the overflow/sump. So in my case, my Reefer 250 has a 660 max flow and the Syncra 6.0 is 530 to 1450GPH which I figured would be ok. The Sicce rep said that the minimum it can run is 5% and indeed the flow will be about 530 but will fluctuate up and down at that speed. I'd need to run at about 14% which is also a no go. So to answer the question of how low can it go, the answer is off or the min GPH at 5% power (so for the 6.0, 530 at 5%) but not stable at the lowest. So the approximate flow you'll get is the Range x % + minimum. If I set the 6.0 at 43% for instance (it's one of the possible set points) I would get 920 (the range) x .43 which is 395 + 530 (min) = 925...way over the max for a Reefer 250. Sicce is being incredibly cool and replacing the 6.0 for a 3.0 at no cost since I just purchased it a few weeks ago (yeah, I lose the $60 extra I paid but would lose that selling it anyway or more).

Anyway, hopefully this info helps someone. Happy reefing all.

 

[MIke Wood]

I'm a year late to this post but I'm having a problem with water level stability in my overflow with my Sicce Syncra SDC 6.0 in my Reefer 250 V1 after upgrading from my super steady but 7 year old Eheim. My level is going up & down all day and then way down or way up etc... Without my ATO it stays for a stable for a day or two but if I turn on my ATO, my system simply can't adjust when water is added. After reading dozens of posts that don't seem to help, I called Sicce and figured the information could be helpful to someone with this issue even if a year after the OG post.

Sicce said that absolutely the power level is a percentage of the RANGE not the total (before head loss). Similar to what the Tunze rep told someone who posted previously, the pump will not be stable long term with anything under 30% and they recommend 40% for a daily setting in order to maintain a proper stable water level in the overflow/sump. So in my case, my Reefer 250 has a 660 max flow and the Syncra 6.0 is 530 to 1450GPH which I figured would be ok. The Sicce rep said that the minimum it can run is 5% and indeed the flow will be about 530 but will fluctuate up and down at that speed. I'd need to run at about 14% which is also a no go. So to answer the question of how low can it go, the answer is off or the min GPH at 5% power (so for the 6.0, 530 at 5%) but not stable at the lowest. So the approximate flow you'll get is the Range x % + minimum. If I set the 6.0 at 43% for instance (it's one of the possible set points) I would get 920 (the range) x .43 which is 395 + 530 (min) = 925...way over the max for a Reefer 250. Sicce is being incredibly cool and replacing the 6.0 for a 3.0 at no cost since I just purchased it a few weeks ago (yeah, I lose the $60 extra I paid but would lose that selling it anyway or more).

Anyway, hopefully this info helps someone. Happy reefing all.

Super old post. But I have the 6.0 and I'm glad I saw this post because I thought my pump was either dying or I was just over tweaking my gate valve. I have the sicce 6.0. It doesn't increase by 1% it will go from 38-43%. Did yours do this?

 

[Dweezilz]

Super old post. But I have the 6.0 and I'm glad I saw this post because I thought my pump was either dying or I was just over tweaking my gate valve. I have the sicce 6.0. It doesn't increase by 1% it will go from 38-43%. Did yours do this?

I can't remember about the 6 but that sounds familiar. From what I recall my 3.0 did go in 1% increments but there were times when it would 'jump' and not stay on the number I set so I had to try a few times. In the end, the 3.0 was not enough flow and the 6 was too big so I ended up getting a Vectra S2 which is perfect at 85-90% and very compact. The mobius app is not as good but it's good enough.

 

[KStatefan]

Sicce must have different firmware depending on when it was made. None of mine will adjust down to 1%. My SDC 3.0 adjust in 1% incriminates and my SDC 7.0 in 3-4% incriminates

 

[Dweezilz]

Sicce must have different firmware depending on when it was made. None of mine will adjust down to 1%. My SDC 3.0 adjust in 1% incriminates and my SDC 7.0 in 3-4% incriminates

I'm pretty sure my 6.0 was in 3 or 4% increments now that I think about it and my 3.0 was 1%. They were so touchy though. I remember I'd put it at 75 and it would jump back to the original number so I'd have to try a few times before it stuck. I can't remember what I did but there was some trick getting it to stay more often the first time, which I figured out a few months before I got the Vectra. Not sure about going down to 1% if that's what you mean but going past 30% is useless since it can't keep a stable flow and will fluctuate. Not sure if that's what you were saying. I wonder why they all won't do 1% increments though. This all reminds me I need to sell the 3.0.