I recently hooked up a sequence marlin in my tank (14-16 feet of head) - I was pretty happy with the flow, but then I hooked up my penductors (colossal increase in flow within the tank) but the amount of return to my sump greatly decreased - not even enough to run my skimmer that I had plumbed from the overflow (requires 800 gph minimum) - I see that sequence has another series of pumps that do more volume at the same head but are not pressure rated? such as the seq4300, 5000, 5800 - would one of these pumps be better or is that too much head for them? (I guess I don't really understand the pressure rating stuff - if it has more flow at the same head, isn't it superior, even if it is not "pressure rated"?) - the other confounding factor is that I have 1" return line and I think that that series has 1.5" returns - would it hurt the pump to reduce to 1" after 8 feet?
sequence pump expert needed
- Thread starter dolt
- Start date
xtrstangx
Premium Member
You probably want a pressure-rated pump to drive your penductors.
Penductors require a lot of force to push the water through them the right way. If you have a flow pump (non-pressure rated), then it can't provide the force... the Penductor puts a lot of head pressure on the pump, basically.
Penductors require a lot of force to push the water through them the right way. If you have a flow pump (non-pressure rated), then it can't provide the force... the Penductor puts a lot of head pressure on the pump, basically.
yeah - that is a good point - if I look at my return, which now is less than 800 that puts me at least at the equivalent of 30 feet of head on the marlin pressure curve, which is beyond the shut off point of the other series - I just was looking for something with a little more oomph, but as quiet as a sequence - it is beginning to appear that there is no such thing available and that I may have the best pump for my application already (which is a relief as I bough two as the price was too good to turn down - now I have one for a backup)
Petsolutions
New member
pump pressure
pump pressure
I am not sure if this is an option you want to use, but since you already have the second pump, you could plumb the output of the first pump into the inlet of the second pump and effectively "double" your head pressure rating to maintain a higher flow rate even with the penductor.
Don Roberts
Petsolutions Customer Service
pump pressure
I am not sure if this is an option you want to use, but since you already have the second pump, you could plumb the output of the first pump into the inlet of the second pump and effectively "double" your head pressure rating to maintain a higher flow rate even with the penductor.
Don Roberts
Petsolutions Customer Service
Don - that is a good thought that I was not aware I could do, but those both draw quite a bit of power (the old one was a big gen x) - I was just hoping that there was a single more powerful pump to hook up but I guess there is not - I really like the eductors so I think I am just going to leave them on - the flow in the tank is amazing
- one other area I might improve though is my plumbing - I have four 90 degree turns - would it make a big difference to remove the 90 degree pvc elbows and replace the turns with a more gentle spa flex arcing turn? I could change three of four but the last one is impossible to get to (is between the heating ducts and floor) - I might do that if it would change much in my outflow
- one other area I might improve though is my plumbing - I have four 90 degree turns - would it make a big difference to remove the 90 degree pvc elbows and replace the turns with a more gentle spa flex arcing turn? I could change three of four but the last one is impossible to get to (is between the heating ducts and floor) - I might do that if it would change much in my outflow
In hobby level sequence pumps, the marlin is your best best with the penductors. That's what I use.
If you have more flow in the tank, I'm not sure why you need more over the overflows. But you can switch to the larger orifice penductors or more penductors to reduce your head presssure. Might even increase in-tank flow depending on where on the pump curve you currently sit.
[Edit: the marlin can be pretty quiet - for the flow. I had problems with mine at first, but a little breakin and changing the inlet to rubber coupling seems to have made it no louder than a constant hum. About as loud as a computer fan. Not silent, maybe a little louder than my iwaki55rlt was]
If you have more flow in the tank, I'm not sure why you need more over the overflows. But you can switch to the larger orifice penductors or more penductors to reduce your head presssure. Might even increase in-tank flow depending on where on the pump curve you currently sit.
[Edit: the marlin can be pretty quiet - for the flow. I had problems with mine at first, but a little breakin and changing the inlet to rubber coupling seems to have made it no louder than a constant hum. About as loud as a computer fan. Not silent, maybe a little louder than my iwaki55rlt was]
KH971 - yes I like it very much - it is very quiet - it is in my basement so it is less of an issue for me, but it is much quieter than my old gen x, or the Iwaki I had also - it is not silent, but very close and the best I have heard especially if you use padding and using rubber couplings as above
Gudwyn - my main reason for wanting more flow back to the sump was to feed my skimmer - one of the main reasons I changed pumps was to be able to feed my skimmer from my overflow, which worked until I added the penductors and then it fell much below the requisite 800 gph - I fixed that problem by supplementing skimmer flow with my old Iwaki 40 RT (I was really hoping to avoid adding that second pump with more energy, noise etc)
Gudwyn - my main reason for wanting more flow back to the sump was to feed my skimmer - one of the main reasons I changed pumps was to be able to feed my skimmer from my overflow, which worked until I added the penductors and then it fell much below the requisite 800 gph - I fixed that problem by supplementing skimmer flow with my old Iwaki 40 RT (I was really hoping to avoid adding that second pump with more energy, noise etc)
dolt, that makes sense.
Do consider switching to a larger orifice penductor, I played around with that for a while and found that two of the large orifice penductors and one of the small orifice worked best on my setup.
You have an extra 8ft of head so you might want to use more of the large orifice penductors. Each of the .35 orifice penductors flow about twice the 0.30 orifice.
Do consider switching to a larger orifice penductor, I played around with that for a while and found that two of the large orifice penductors and one of the small orifice worked best on my setup.
You have an extra 8ft of head so you might want to use more of the large orifice penductors. Each of the .35 orifice penductors flow about twice the 0.30 orifice.
If you didn't ask for large orifice, you have the standard size 0.30 size.
http://www.kthsales.com/website/Misc/Low pressure eductor flow rates.pdf
You can see the 0.375 (I was wrong about the 0.35) runs almost twice the flow at the same head pressure. So when you switch you'll get more flow from your pump, but a less powerful eduction. At some combination, you'll hit the sweet spot.
Who knows, maybe you are already at the sweet spot and the in-tank flow can only get worse. But by switching to the larger orifice, you'll definitely get more flow thru the sump.
http://www.kthsales.com/website/Misc/Low pressure eductor flow rates.pdf
You can see the 0.375 (I was wrong about the 0.35) runs almost twice the flow at the same head pressure. So when you switch you'll get more flow from your pump, but a less powerful eduction. At some combination, you'll hit the sweet spot.
Who knows, maybe you are already at the sweet spot and the in-tank flow can only get worse. But by switching to the larger orifice, you'll definitely get more flow thru the sump.
You don't say how many penductors are on your tank. But looking at the Marlin pressure curve, you must be placing at least 32' of head pressure on that pump to get below 800gph.
14-16' plus four 90s is probably around 18' of pressure. Leaving 14' for the eductors.
Two 0.30 eductors at 14' of head will flow 5.4*2*60 = 650gph. So my guess is you have two 0.30 eductors.
Increase those to dual 0.375 and you'll flow around 900gph. The Marlin puts out 25' of pressure at 900gph and dual 0.375 eductors will also flow about 900gph at 7' of head pressure. So that's about the ballpark.
14-16' plus four 90s is probably around 18' of pressure. Leaving 14' for the eductors.
Two 0.30 eductors at 14' of head will flow 5.4*2*60 = 650gph. So my guess is you have two 0.30 eductors.
Increase those to dual 0.375 and you'll flow around 900gph. The Marlin puts out 25' of pressure at 900gph and dual 0.375 eductors will also flow about 900gph at 7' of head pressure. So that's about the ballpark.
