my diy needle wheel dart pump

[jnarowe]

dwell time may be right. When I watch my skimmer neck, I see a significant number of bubbles going down as well as up. I have never studied skimmers that closely but have'n't noticed that in any other skimmer. I am getting an abnormally high dwell time I believe, based on what others have posted on the subject.

And BTW, I believe that is due TO the turbulence created by the inbound water entering just below the riser cone.

 

[Roland Jacques]

<a href=showthread.php?s=&postid=7211495#post7211495 target=_blank>Originally posted</a> by weatherson
That's patented, by the way.

whats patented the 45 degree angle cut? or the offset? amazing what can be patented. what if i use a 40 degree cut. dose the patent still apply?

 

[Travis]

<a href=showthread.php?s=&postid=7212478#post7212478 target=_blank>Originally posted</a> by jnarowe
When I watch my skimmer neck, I see a significant number of bubbles going down as well as up. I have never studied skimmers that closely but have'n't noticed that in any other skimmer.

IMO and IME, that is caused by too much turbulence. I had that same problem all of the time with my Beckett skimmers. I never could get them tuned so that the bubbles would rise only instead of going up and down in the skimmer neck. I don't have that problem with my BK or any other needlwheel design I've ever ran. I feel that the bubbles going up and down in the neck greatly decreases efficiency.

 

[jnarowe]

Well, I would agree if it weren't for the mountain of foam and literally BLACK skimmate. I am very sure it would be more efficient with a NW because the bubble size would dramatically decrease offering an exponentially larger amount of surface area presented to the pollutants for adhesion, but I am not convinced that turbulence decreases the efficiency of my skimmer.

The reason being is that getting more dwell time gives pollutants ample opportunity to adhere to a bubble. There is less "luck" involved in the skimming process when you increase dwell, IMO.

 

[RGibson]

A hole to small

A hole to small

<a href=showthread.php?s=&postid=7213103#post7213103 target=_blank>Originally posted</a> by Travis
IMO and IME, that is caused by too much turbulence. I had that same problem all of the time with my Beckett skimmers. I never could get them tuned so that the bubbles would rise only instead of going up and down in the skimmer neck. I don't have that problem with my BK or any other needlwheel design I've ever ran. I feel that the bubbles going up and down in the neck greatly decreases efficiency.

Most needwheell skimmers have holes in the lid to let the air out and do a much job of it then Beckett skimmers who have a very small hole in the side of the cup to let the air and water out at the same time.This is not a good way to vent the air.

 

[RGibson]

Travis my Beckett i have a 1 in vent in the lid and it works very well.

 

[gath2]

Without the air tight compartment, you can't use an auto shutoff collection cup. Mine has come in quite handy when I made an adjustment and came back an hour or two later to see the cup filled and what could have been a huge mess.

 

[jnarowe]

Good point!

 

[RGibson]

lid

lid

<a href=showthread.php?s=&postid=7213213#post7213213 target=_blank>Originally posted</a> by gath2
Without the air tight compartment, you can't use an auto shutoff collection cup. Mine has come in quite handy when I made an adjustment and came back an hour or two later to see the cup filled and what could have been a huge mess.

I have a auto shutoff in the lid.

 

[Stile2]

I am chiming in here with admitedly very little experience with DIY skimmers (I have built two, one CC and one NW).

While the turbulence does extend the dwell time, so proteins have more time to attach to bubbles, the turbulence also can cause more bubbles to "crash" into each other and form bigger bubbles. I believe this is why my NW skimmer is burping.

So in shorter skimmers some turbulence could be a good thing, n taller skimmers I would think that the turbulence would be a hindrance.

Keith

 

[LA-Lawman]

did you graduate the collection cup to measure skimmate? that would prolly help with tuning...

 

[jnarowe]

say what? you mean put markings on the cup and calculate rise vs. time?

 

[weatherson]

<a href=showthread.php?s=&postid=7212850#post7212850 target=_blank>Originally posted</a> by yourfishman
whats patented the 45 degree angle cut? or the offset? amazing what can be patented. what if i use a 40 degree cut. dose the patent still apply?

As I didn't think anyone would really think that I patented such a thing, that was a joke. There is no patent for cutting the riser at an angle. As far as I know, nor has anyone else so it's free to use and I recommend doing so. It does actually work quite well. Sorry if my attempt at humor caused any confusion.

 

[jnarowe]

What's funny about that is I, having had a large stroke, have difficulty with humor sometimes, but fully understood it was a joke because you used a .

I really think Bill may benefit from using that idea.

 

[slug]

By cutting riser at an angle do you mean the riser tube cut at an angle? Could you explain please?

 

[Beenalongtime79]

<a href=showthread.php?s=&postid=7213148#post7213148 target=_blank>Originally posted</a> by jnarowe
Well, I would agree if it weren't for the mountain of foam and literally BLACK skimmate. I am very sure it would be more efficient with a NW because the bubble size would dramatically decrease offering an exponentially larger amount of surface area presented to the pollutants for adhesion, but I am not convinced that turbulence decreases the efficiency of my skimmer.

The reason being is that getting more dwell time gives pollutants ample opportunity to adhere to a bubble. There is less "luck" involved in the skimming process when you increase dwell, IMO.

Turbulence at the foam forming interface is not a good thing and also turbulence in the water column is not a good thing when you are trying to reach close to air saturation as your bubbles are more likely to coalesce. Sure, your skimmate is black, but that doesn't mean you are running an efficient design (not saying that you aren't, but just saying that anybody can get black skimmate if they try hard enough, and with a tank of your size and I can only imagine bioload, I'd be afraid if you weren't making some dark, nasty stuff). Looks like it is performing well Bill, it really looks like you might not even need an additional airpump, especially if it producing enough bubbles to create that density. I think it's pretty amazing that you are spending less than 300 watts to fill that whole damn column up!

Peace,
John

 

[Beenalongtime79]

I personally think cutting the riser tube at an angle gives you no advantage. It's not advantageous or disadvantageous.... I think it's pretty much the same as saying, cut your tube down a few more inches so that the riser tube is shorter.

It doesn't hurt, but doesn't really add any additional efficiency and with that angled cut design, it makes it harder to design a wet neck for it. IMO folks.

Peace,
John

 

[Roland Jacques]

<a href=showthread.php?s=&postid=7214206#post7214206 target=_blank>Originally posted</a> by weatherson
Sorry if my attempt at humor caused any confusion.

Thanks brother, lately I don't doubt any patents. I should have read your name first I might have gottin it. but then again im kinda slow.

Slug,
check out jnarowe post near the top of this page. Link to weatherson web page. weatherson makes a real nice small little cute skimmer. click on Skimmer construction

 

[jnarowe]

John,

My skimmer is pulling out black skimmate with no "tuning" to speak of and 9 chromis in a 1,100g system. I would call that an extremely light bio-load. And if you think that cutting the riser at an angle offers no advantage, then I think maybe you haven't studied how foam reacts under its own weight and how that reaction can be changed by making this cut. I think someone else could probably explain ti better but I will try.

Surface tension plays a key role in what your foam head does as it travels up the riser and when you have a straight top, the head is more likely to collapse on itself because it has equal surface tension all the way around. When you make this cut, the head continues up the riser but the tension is broken on the low side of the cut allowing the foam to spill over the side easier and lessening the weight and tendency to burst before spilling. Does that make sense to anyone other than me and Weatherson? Doesn't matter. It works extremely well and I am really glad I did it. of coure I have over 24" of 6" diameter riser so I could "afford" the cut.

 

[Roland Jacques]

Jonathan

Understanding the benefits without seeing it in action can be hard to understand. Once I saw one work it becomes clear to the benefits of that angled neck. It also seems that it would keeps your neck cleaner longer and that alone is good enough for me to have one.

The wet neck is the one im having trouble with. I understand in theory how it works, but I not sold yet. I would like to no more about those wet necks.

Anybody have a link on the wet neck info?