More on penductors...

[Jessezm]

Who wants to help me think this through...?

I finally got two penductors working well on my two returns in my 120. However, I noticed that the flow out of both overflows has been severely reduced. It seems like I'm getting about half of what I was getting before. The pump I'm using at the moment is a Blueline hd55 (panworld 150hs). Without the penductors on, I had to throttle back the pump because the overflows couldn't quite handle the flow. Now I have the opposite problem--tons of moevement in the tanks (I estimate about 3000 gph counting what the Tunze Stream moves), but probably only about 500-700 gph is going through the sump and refugium from the overflows.

My question is, are there any real drawbacks to cutting back the flow through the variuos filters this much? The benefits would seem to outweigh them, given the addition of suspended particles in the water column to be skimmed. Any ideas? I'm still playing with the setup for now. Thanks,
--Jesse

[dme330i]

I don't think there would be any significant negatives. Does the overflow rate match your skimmer input/capacity (assuming your skimmer draws from the sump)? If not, it might affect the overall efficiency.

[twd4]

I would say it will have a large impact on your systems filtration. That surface skimming is what removes particles, organics, detritus , etc, etc from your tank. The lower your turnover rate the longer fish waste and uncomsumed food will remain in your tank. You dont want these things breaking down in your tank, you want to get them out of the tank and through the filter socks, spong blocks, and skimmer asap. This also changes the amount of "dirty" water that gets fed through the refugium in most cases. I proly always overdo things but i always try to max out my overflows meaning i want as much turnover as my tank will possibly allow. Not to say that your tank is gonna crash or show any deline at all but it just makes since to have your tank running at max efficency(sp?) $.02

[Jessezm]

Good points, both...well the reason for adding the penductors was to get more circulation in the first place--I have a general feeling that my system is not well balanced at the moment--LPS are showing signs of decline and Cyano necessitates a daily basting of all corals, live rock, and sandbed. The added flow after changing the plumbing and pump was overwhelming my overflows and submirging my EV-180 above the gate valve, as well as my auto-topoff float switch which adds extra hassle. Another result was that the extra water in the sump was dropping the level in the refugium significantly--water returns to the tank from the main refugium and it was being pumped out faster than it was filling back up from the two overflows (one goes to the sump and skimmer first, and then flows to the refugium via a balancing tube; the other goes straight to the refugium).

Anyhow, I thought I could cut back the overall volume flowing throught the overflows while increasing internal circulation by adding the penductors. I guess it worked too well, and now I have to figure out how to get MORE water through the overflows. Any ideas/suggestions on how best to do that?

And by the way, I am not using a filter sock or filter media of any kind at the moment, and the result is a good bit of detritus EVERYWHERE I think. I am running a DSB in my 50 g refugium with chaeto and some other macros, and in the sump, which holds my skimmer, there is a smaller refugium with Carrib-sea mineral mud in it. At this moment in time, I don't hvae a good place to put carbon or purigen that will get good flow without overflowing the skimmer section of my sump. I do have a bag of matrix carbon sitting in in the mineral mud section of my sump. Any other thoughts?

Thanks!
--Jesse

[twd4]

tell me more about the return plumbing coming from your blueline hd55. My catalog here says that pump is 1100gph@0' head . IMO that pump is too small for a 120 gallon reeftank when you are trying to do more that a single return. When you start doing multiple returns from your main pump ,which everyone wants to do so they can cut down on ugly powerheads, all the excess plumbing you add really starts to add head pressure and cut down your flow.

i would like to know your plumbing scheme so i can calculate your headpressure. with that pump its very possible your only seeing 500-600 gph which means you only have a few hundred gph coming out of each of your two returns. what size penductors do you have. i am no expert on them but i thought a 3/4 or 1 " penductor required close to 1200gph each. i think you need more pump or a more efficient plumbing method, possibly both....

[Jessezm]

Okay, here goes--I took pictures last night and will try to upload tonight when I get home:

The return pump is hard-plumbed external to the 50g refugium. The intake pulls water through a 1" bulkhead in the refugium. Water feeds from the bulkhead through about 4" of hard PVC, then through ball valve. There, it makes a 90 degree turn (because of space), and goes on through a 1" threaded union and into the pump. On the return side, there is a 1" threaded union with an integrated ballvalve (single unit). Then it goes through a 1" mpt X slip adaptor into a slip TEE, where the 180 degree part of the TEE is straight up and down. The 90 degree heads off to the left via 1" flexible PVC and then curves straight up about 1'. There is another 1" slip union here, then is reduced to 3/4" with a slip X FPT bushing and connects directly to the return bulkhead through a 3/4" MPT X MPT nipple. From the bulhead, water goes up through 3/4" hard PVC, hits a 90 degree elbow at the top, and then to loc-line which has the penductor at the end. The other return is set up the exact same, except that the flex PVC goes straight up at the TEE, but then bends and travels the length of the tank (about another 4') underneath it to the bulkhead on the opposite corner.

It may sound like a lot, but basically, it's 1" all the way to the bulkheads, with only one TEE and no 90 degree turns on the return side. I took special care to reduce friction in the plumbing by mating all fittings together firmly so there would be totally unobstructed flow through them. There is about 5 total feet of lateral flow and and maybe 6 total feet of vertical flow between the two returns.

With these changes over the previous set-up, I saw vastly improved flow (the previous set-up reduced to 3/4" at the TEE, went through 2 aditional ball valves, had a bunch of barbed adaptors, and had much more lateral and verticle head). As I said, without the penductors, there is too much flow for the drainpipes. The drainpipes are 1 1/4" Dursos which reduce to a 1" bulkhead. One flows directly to the refugium and the other flows through the wall to the sump in the closet. The sump is 30"X12"14", and has a skimmer box, which goes through a baffle to a refugium compartment, then through another baffle to the return bulkhead. This bulkhead is plumbed with 1 1/4" hard PVC through the wall to a bulkhead halfway up the side of the 50g refugium. It serves sort of as a balancing tube--the levels in the sump and refugium equalize when the flow is right. I think part of my problem right now is that the sump may not be able to handle the flow, given the water isn't proactively pumped out to the refugium, but rather, passively flows through it via gravity. I really have no idea what to do about that--but it worked fine before I streamlined the plumbing and changed the pump.

Now, when I added the penductors, that's when the flow through the overflows slowed down, and the level in the sump returned to normal. I imagine the pendctors must add TONS of head pressure, but the Blueline 55 and the GEN-X 55 I tried running before I got a great deal on the blueline are both pressure rated pumps, are they not? (one caviat here--I haven't tried running the Gen-X with the penductors to observe the effects on flow--I can do this tonight if you think it would make a difference between these pumps. Before all this, I was running an old T4).

Anyhow, I'm not going to a larger pump just to run the penductors--They are VERY productive at the moment anyways. Another thought I had is that without the penductors, I was running the loc-line returns without the return nozzle--reason being that to put a penductor on a loc-line return, you add a double-sided piece of loc-line (not reducing), and then add a 3/4" mpt loc-line adaptor so the threads are on the return side, which you can then thread the penductor onto. Without the penductor on the end of this you have no added head pressure from the usual loc-line nozzle, thus I may have increased my flow here. Maybe without the penductors, but with the return nozzle, I'll add just enough head pressure to return things to normal...(but then, of course, I'll be without the penductors!)

Well I hope that's not too convoluted a picture of my plumbing scheme... To review, I see several possible problems:
1) W/OUT the penductors, flow is too much for either the sump, the overflows drains, or both. This MIGHT be fixed by adding a little extra head pressure with return nozzles at the ends of the loc-line returns.
2)WITH the penductors, there is simply TOO MUCH head pressure for the pump to circulate enough water through the system. Is a bigger pump the only solution? I imagine any more flow through the penductors would turn my tank into a whirlpool!

Do you think my thinking is about right, here? I'd also be interested in other suggestions on how to reduce the detritus factor. Thanks,
--Jesse

[twd4]

there are just so many factors here. i am looking forward to seeing pics of this plumbing. i always like to add any Ts as far from the pump as possible. i also ALWAYS use all the drilled holes as drains with dursos and bring my return plumbing up and over the back of the tank so i dont wanna say that you shouldnt have any problem with too much flow with ALL that plumbing. Lets have a look at the pics of your drain and return plumbing and go from there. I would even like to see some pics of your dursos, were they bought or made or what????

[Jessezm]

Alright--lookout for a late-night addition with pictures and some tipsy ramblings, as I'll be coming home from the boys' night out and I plan on putting a few back...

I remember you sharing this manifold idea with me--it's just not possible to do at this point, unfortunately--I don't have the space behind my tank, and I don't think the sump could handle another drain. This was my first big tank, and I bought the entire set-up used so I'm making changes to it as I go...(hence the much-improved plumbing and new pump). The Durso's have the Savco brand name on them, but I have no way of knowing whether they're home-made or not. I'll try to include some pictures of them, too.

Thanks,
--Jesse

[cyberchef]

Put a "T" before each penductor with a fitting reducing it down one size (ie: 3/4" to 1/2" or 1" to 3/4") on the side that does not go to the penductor. Thus would increase your overall flow through the tank but it might also reduce the effectiveness of the penductors. From the sounds of it, the amount of flow through the tank should be fine given the amount of flow inside of the tank. By slowing the flow of water through the sump you are actually allowing the skimmer more time to be more effective with the the water it is being supplied with. If your flow through the sump is too great, the suspended particles will only pass through the sump with only a small portion of them being able to be removed by the skimmer.

[Jessezm]

Great idea!

[Geoff]

for such a simple device, figuring out what they really do is complex.

they add a lot of head pressure, they need to in order to produce the low pressure area around the nozzle to suck in the surrounding water to increase the total flow. now whether or not they actually increase the total flow is completly based on the pump. if it is not a pressure rated pump (like the T4) then you may actually see a decrease in total flow out of the outlet. lets say a T4 pumps out 1200gph at 3' and that is where the tank is. lets say you put an eductor on it. they like to be run at at least 10psi which translate to 23' of head pressure. at this pressure the T4 is not rated this high. therefor it is not really getting the 4-5X flow at the nozzle that eductors are known for. at 18' the T4 can only do 120gph. so even if it was powering the eductor at 4-5X the nozzle flow its total flow is only 600gph. this is significantly less than if you were to just run the T4 wide open.

on the other hand if you were to use a T3 pump. the tables are turned. at 3' the T3 pumps out only 800gph, but at 23' of head pressure the T3 is still pumping out 270gph. if the eductor is running at 4x than the total flow out of the eductor is over 1000gph! this makes the eductor worthwhile.

of course the flow into the pump is only 270gph. so your flow through the sump will only be this. this is why CLS's are so popular.

HTH,

G~

[Jessezm]

Yeah, I would suggest penductors on a closed loop at this point...but I'm still experimenting. I'm going to try to dump some extra flow into the tank with a reducing TEE in the loc-line returns, as per cybershef's suggestion, and see if I can still get some performance out of the penductors. In the meantime, I tried putting the original return nozzles back on the loc-line returns after taking the penductors off, and it solved all the issues with the overflows and sump... I guess the added head pressure from the nozzles was all it took to back the flow off just a little. Tom--I'm not gonna get to those pictures tonight. how bout a raincheck? Too tipsy to hook the camera up...
Thanks for all your input so far, everyone!

[SShindell]

I just put two of these puppies on my 400 gallon.

They are incredible. I had to reduce my sequence pumps 60%, and the flow is unbelievable. They still increased flow to the point of increasing the volume of my tank about an inch over what I had it, and now I have to figure out how to quiet the overflows. I am sold and would highly recommend them to everyone.

Steve

[twd4]

Originally Posted by SShindell

I just put two of these puppies on my 400 gallon.

They are incredible. I had to reduce my sequence pumps 60%, and the flow is unbelievable. They still increased flow to the point of increasing the volume of my tank about an inch over what I had it, and now I have to figure out how to quiet the overflows. I am sold and would highly recommend them to everyone.
Steve

Man i guess i need to order a couple of these things to play with. One thing i dont understand is how they can possibly increase flow through the overflow. Everything i have ever learned in school would make me believe quite the opposite. I mean, the most powerful a pump will ever be is with a single return that is in a straight line with no 90s, Ts, or reducers. I understand how they create a larger/wider current thus increasing water movement but they cannot possibly make the pump run faster meaning they should never raise water level in the tank. Someone please fill me in on how they can create more turnover through the sump.

[Jessezm]

I would say they don't, and the extra flow (and apparent extra volume in the tank in Steve's case) is a result of the excess velocity of the water having nowhere to go and causing some displacement, thus splashing over into the overflows. Steve--I wonder if you fiddled with the direction of the currents you could reduce that displacement effect? I am not saying you're wrong (I haven't seen your set-up since you added the penductors), but in my experience the extra head pressure--and in your case having to reduce the output of your pump--would mean less actual turnover, but more circulation. It's like if you take a sumbersible pump and drop it in a bucket of water, and point the return hose back into that bucket but press your finger over the hose so you get a jet stream--you're going to displace water to the edges because of the great velocity, but you're actually taking less water out and putting less water back in because of the added head pressure from your finger covering the whole.

At least that's my theory...