Octopus Skimmer Question

R

regina13

Guest
I think I am going to buy an octopus skimmer in the next month or so and was wondering if it is worth the extra money to get the Recirculating Skimmer over the regular Needlewheel Skimmer? Does it have advantages over the other?
 

hurt

Active Member
Yes, recirc's are better skimmers. You slow down the dwell time between the SW and air to allow for more removal of organics. If you don't mind spending more cash, the performance is better. That being said it is very easy to turn a normal needlewheel skimmer into a recirc skimmer if you are a DIY'er.
 

acrylic51

Active Member
Originally Posted by Hurt
http:///forum/post/2911029
Yes, recirc's are better skimmers. You slow down the dwell time between the SW and air to allow for more removal of organics. If you don't mind spending more cash, the performance is better. That being said it is very easy to turn a normal needlewheel skimmer into a recirc skimmer if you are a DIY'er.
Agree
 

scsinet

Active Member
I have an Octopus recirculator and I can tell you it's worth the extra money.
Recirculating skimmers are all I use now.
 

devil dog

Active Member
Originally Posted by SCSInet
http:///forum/post/2911709
I have an Octopus recirculator and I can tell you it's worth the extra money.
Recirculating skimmers are all I use now.
Can you tell me what the diff in the two? Maybe a pic of yours would help... I have an Octopus and I dont know what one it is...
thanks for the help...
DD
 

hurt

Active Member
In a recirc, the skimmer pump is essentially a closed loop with the skimmer, it takes water from the skimmer body, and injects it back in. You typically either feed the skimmer by gravity, or a small pump such as a maxi-jet. With a normal needle wheel skimmer, the skimmer pump takes in water from outside the skimmer, i.e. the sump. So, recirc skimmers typically have 3 holes with uniseals(2 for skimmer pump, and one to feed the skimmer), while a normal needle wheel skimmer only has 1 uniseal.
 

scsinet

Active Member
Originally Posted by Hurt
http:///forum/post/2912149
In a recirc, the skimmer pump is essentially a closed loop with the skimmer, it takes water from the skimmer body, and injects it back in. You typically either feed the skimmer by gravity, or a small pump such as a maxi-jet. With a normal needle wheel skimmer, the skimmer pump takes in water from outside the skimmer, i.e. the sump. So, recirc skimmers typically have 3 holes with uniseals(2 for skimmer pump, and one to feed the skimmer), while a normal needle wheel skimmer only has 1 uniseal.
What he said.
 

devil dog

Active Member
Originally Posted by Hurt
http:///forum/post/2912149
In a recirc, the skimmer pump is essentially a closed loop with the skimmer, it takes water from the skimmer body, and injects it back in. You typically either feed the skimmer by gravity, or a small pump such as a maxi-jet. With a normal needle wheel skimmer, the skimmer pump takes in water from outside the skimmer, i.e. the sump. So, recirc skimmers typically have 3 holes with uniseals(2 for skimmer pump, and one to feed the skimmer), while a normal needle wheel skimmer only has 1 uniseal.
Thanks Guys!!!! I have a recirc skimmer... would it help to have it feed with a needle wheel pump? Right now iI have a blueline 55 HD that feeds my skimmer... I could get a Big needle wheel pump and use that where i want to... and if it would help that would be win win...
 

stanlalee

Active Member
feed pump cant be an aeration (needlewheel) pump, needs to be just fed straight water
"theoretically" I'd take a same size recirc over a non recirc of the same model everytime BUT I'd also if I had the room go a size up over recircing everytime as well.
the reason I say theorically because I dont see anything about the construction of a non recirc to a recirc that even remotely justifies the price difference between the two so even though I believe it might work moderately better on the same size skimmer I wouldn't pay for it from the manufacturer. I wouldn't pay anywhere near the fifty (on a $150 skimmer) to hundreds (euroreef) of dollars extra. I'd spend that on a bigger or better non recirc.
I'd much rather have the Oct NW-150's 1.5" larger body, height, twice the pump size and cheaper price than the recirc DNW-110 or a MSX-200 and its SICCE pump, modern design and large capacity neck over a more expensive recirc DNW-200. I do like the fact a recirc needs virtually nil adjusting once set, its immunity to water fluctuations and ability to run external but I think the sheer performance benefit is way overstated to justify the price difference of virtually the same skimmer with two added holes, pipe, feed hose adapter and sometimes base plate added. I can do all that sans base plate for $20. Just my oppinion obviously vastly different from the others so far.
 

devil dog

Active Member
Originally Posted by Stanlalee
http:///forum/post/2912712
feed pump cant be an aeration (needlewheel) pump, needs to be just fed straight water
"theoretically" I'd take a same size recirc over a non recirc of the same model everytime BUT I'd also if I had the room go a size up over recircing everytime as well.
the reason I say theorically because I dont see anything about the construction of a non recirc to a recirc that even remotely justifies the price difference between the two so even though I believe it might work moderately better on the same size skimmer I wouldn't pay for it from the manufacturer. I wouldn't pay anywhere near the fifty (on a $150 skimmer) to hundreds (euroreef) of dollars extra. I'd spend that on a bigger or better non recirc.
I'd much rather have the Oct NW-150's 1.5" larger body, height, twice the pump size and cheaper price than the recirc DNW-110 or a MSX-200 and its SICCE pump, modern design and large capacity neck over a more expensive recirc DNW-200. I do like the fact a recirc needs virtually nil adjusting once set, its immunity to water fluctuations and ability to run external but I think the sheer performance benefit is way overstated to justify the price difference of virtually the same skimmer with two added holes, pipe, feed hose adapter and sometimes base plate added. I can do all that sans base plate for $20. Just my oppinion obviously vastly different from the others so far.

Thanks... But I dont get why you couldnt add needlewheel pump to get much more action out of it... I might have to try it and see what happens...
 

stanlalee

Active Member
Originally Posted by Devil Dog
http:///forum/post/2912894
Thanks... But I dont get why you couldnt add needlewheel pump to get much more action out of it... I might have to try it and see what happens...


you need the water pressure from the feed pump which is usually already low to begin with to push the water thru the skimmer. the recirc pump cant push water thru the skimmer because its recircing. aerating the feed water will make the input pressure too weak. those needlewheels strong enough to do both (push water thru the skimmer and add air) will likely overwhelm the skimmer body with too much air. you can try it though. report back how it works out.
 

wattsupdoc

Active Member
My .o2

I will never own an external skimmer never never never(ha those look like edible words don't they
). The possibility of overflowing and draining the tank....not gonna take that risk myself. So, that right there is not a factor in my decision making. Now as far as fluctuating, my in sump skimmer only fluctuates when I shut down the system and the backwash fills it's compartment. A properly designed skimmer compartment will cure the fluctuating...That's not an issue for me either then. How effective a skimmer is would be about all we're left with then. So does a higher priced recirc skimmer perform better than a less expensive NW skimmer? First off, they both use NW's for chopping the air. Actually, the better ones these days use mesh, so maybe we should refer to these as mesh wheel skimmers ?
I have a mesh wheel octo 200. The funnel neck jobber. I cant imagine it skimming any more crud out of my 135. Definitely it seems to remove more than I'm putting into it. It is set up so the output of the skimmer is directed towards the intake of the sicce pump( replaced the octo pump with the sicce, which I feel is an overrated((but good)) pump). I have what I feel to be an equal flow through the sump as what the skimmer is moving, Probably 400 gph. The output faces into the current flowing through the sump, and so does the intake. You can see with this arrangement, I am surely recircing some water..... How much?who knows? Just how exactly do you know how many times a water molecule gets recirculated in a recirc skimmer before it's put back? I dunno, that's not my department.
My point is probably more lined with Stanlalee. A non recirc skimmer can EASILY be modded to be a recirc if you desire. Also, there are instances when a non recirc skimmer will do just as much as a recirc. If there's nothing to skim, what can it skim?
My point on the sicce pumps. I had the original octo 3000 that came with my skimmer. I broke one of the last three arms off the impeller when modding it. Because I had heard SOOOOO much about how these pumps are the shnizzle and the octo pump bite hard. I figured it would be best to just get the sicce pump and save some cash by using less power. Well, as far as performance goes. My old octo 3000 did just as well as the sicce does. Both pull around 30scfh each pretty reliably. The octo just consumes more power to do it, as well, the sicce is more compact, heats up the tank water less I presume. As a direct result of using less power. Overall though, I'm not too enthused with the sicce.
My .02
 

scsinet

Active Member
Originally Posted by Devil Dog
http:///forum/post/2912894
Thanks... But I dont get why you couldnt add needlewheel pump to get much more action out of it... I might have to try it and see what happens...

I suppose that might work, but keep in mind that when the bubble-laden water passes through the recirculating pump, all bubbles are destroyed and re-created, starting the skimming process all over again.
Considering that the idea is for water in the skimmer body to pass through the recirculating pump multiple times before ultimately leaving the skimmer, going to the trouble of putting a needle wheel on the intake is not going to gain you much.. one "cycle" maybe.
I don't believe that pressure is an issue, the very idea of recirculating skimmers is that they do not need signficant pressure to run them as other designs do. You can even feed recirculators off the gravity drain from the tank (though it's not commonly done).
A good recirculating skimmer works so well that I can't imagine getting "more action" out of it anyway.
Wattsup, I don't understand how a skimmer can really overflow? If the skimmer collection cup fills up, won't water just overflow back down the neck and into the skimmer? The only overflow scenario I can picture is when the collection cup is plumbed into an external canister....
 
I'm a little confused here too. A skimmer can overflow and cause a mess but not to the point where it "drains" a tank. You can also mod them to where an overflow won't be an issue if it does happen.
 

wattsupdoc

Active Member
It can definitely cause some issues. Even crash a tank. What I meant was draining the tank of salt, so to speak, by being connected to an ATO, it will likely continue to fill and cause the SG to shift......Ask Steve West(OregonReef) about that scenario. Also If the SG doesn't shift enough to be an issue, or no ATO connected, then it can cause your return pump to run dry....."Draining" the return pump compartment.
 

wattsupdoc

Active Member
Originally Posted by SCSInet
http:///forum/post/2913116
Wattsup, I don't understand how a skimmer can really overflow? If the skimmer collection cup fills up, won't water just overflow back down the neck and into the skimmer? The only overflow scenario I can picture is when the collection cup is plumbed into an external canister....


If the return pipe becomes blocked it cant exit the skimmer....If the skimmer starts skimming erratically, it can lift the lid of the collection cup and spill over the sides. This can happen when the skimmer fills the cup and already skimmed Doc's are flushed back down into the chamber.
Also, if I understand correctly, many recirc skimmers pull water that is bubble free to recirc. Just because the water has become bubble free, doesn't mean previously unattached DOC's wont be attracted the second time around. My point is the skimming process doesn't start all over again necessarily, some DOCS remain attracted to the air for a while after first being introduced to it. MY understanding is this is an IONIC or polar attraction, or something similar to that anyways......
 

devil dog

Active Member
I'm sorry i took this thread over... and thanks I see what you are talking about... But all my stuff is external I just dont have the room for that big skimmer in my sump...
I think it is 36" tall
 

wattsupdoc

Active Member
Which is the case with many systems. And most likley you'll never really have a problem, but the chance is there and not one I will likely ever take. Just my point of view there....
 

stanlalee

Active Member
Originally Posted by SCSInet
http:///forum/post/2913116
I don't believe that pressure is an issue, the very idea of recirculating skimmers is that they do not need signficant pressure to run them as other designs do. You can even feed recirculators off the gravity drain from the tank (though it's not commonly done).
....

I'm not saying it wont work but its PROBABLE if you use a needle wheel feed pump that can aerate/provide additional bubbles AND pump enough water to provide 1.5x turnover of water you are either going to have a skimmer over whelmed with air OR your not going to have satifactory tank turnover which you want at least 1.5x per hour. take a 75g with the DNW-150 and OTP-1000 NW for feed pump. that pump is rated for 260gph just water and MIGHT provide 113gph needed for 1.5x turnover used as an aerator and feed pump with head loss but its almost garuanteed to overwhelm the DNW-150 body with additional air. that would be the equivalent of a DNW-150 with a 790gph OTP-3000 recirc pump (used on the DNW200 and NW200). in order to use a NW small enough not to overwhelm the skimmer body with air you will LIKELY have to use one too small to provide enough pump (water) pressure to provide 1.5x turnover at which point your just re skimming the same water over and over while the other 40,50, 60% of tank volume isn't getting skimmed at all. could there be a skimmer with a recirc pump so undersized/under performing or height and neck so large and under driven it could be possible to do this effectively? its possible but its HIGHLY unlikely a DNW-110,150 or 200 can (or any skimmer that the pump is matched well with the body).
Also adding a needle wheel feed pump SHOULDN'T re chop the bubbles that enter the skimmer. the bubbles coming in the skimmer should rise to the top and just the water should be recirculated just like what happens to the water that exits the recirc pump. it WILL happen because more than likely you will overwhelm the skimmer with air which has no where else to go (except overflowing the collection cup which you dont want either so you will open the gate valve/lower the riser and lower the water level which will cause the air to be re chopped on a recirc and zillions of micro bubbles on a non recirc overwhelmed with air. either way counter productive)
 
Top