my diy needle wheel dart pump - Page 36

trmiv · #**876** 04/20/2006, 12:07 AM

Whoa! Now I need to find a way to fit this under my 90 gallon's stand.

jnarowe · #**877** 04/20/2006, 12:16 AM

Looks great Bill. Just like mine in skimmate. I love the fact that it really didn't need a "break-in" period like so many commercial brands. Mine starting skimming right away too. What is interesting is that your foam looks exactly like my foam and yet we are using entirely different air injection methods.

Do you think you have enough clearance on the lid? If you cut the top of the riser at a slight angle that will get the foam to spill off better and not collapse under its own weight. Check out Weatherson's skimmer construction for a good pic of what I mean. It really works well.

Work of art man.

weatherson · #**878** 04/20/2006, 12:46 AM

That's patented, by the way.

Nice skimmer and acrylic work guys. I've been following along in amazement.

hahnmeister · #**879** 04/20/2006, 02:21 AM

jnarowe's right. The skimmer lids are made to constrict the flow of air around the top of the riser neck to create a pressure surge at this point which discharges the foam downward.

I seriously dont think that that skimmer neck is large enough...it should be a much larger diameter and maybe lower...otherwise the neck just gets caked with poop deposits too easily (And then performance drops). A 12" neck at least...

Speculation of course, but I bet that the reason for the similar foam color/appearance isnt because of the method of injection, but the dwell time that each bubble has. The longer dwell time, the stronger each bubble will be, and the darker, more vile proteins will get extracted (black sludge that shorter skimmers cant get at).

I really dont think that more air will do much for you at this point. There is so much already, that you might go beyond the threshold where the extra bubbles just cause more turbulence with each other as they rise. As is...its looking like its doing great. I am in envy.

SHARKSRME · #**880** 04/20/2006, 02:28 AM

how many gph are you putting through it?

jnarowe · #**881** 04/20/2006, 08:45 AM

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 · #**882** 04/20/2006, 09:53 AM

Quote:

Originally posted 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 · #**883** 04/20/2006, 10:29 AM

Quote:

Originally posted 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 · #**884** 04/20/2006, 10:40 AM

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 · #**885** 04/20/2006, 10:44 AM

Quote:

Originally posted 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 · #**886** 04/20/2006, 10:49 AM

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

gath2 · #**887** 04/20/2006, 10:52 AM

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 · #**888** 04/20/2006, 10:57 AM

Good point!

RGibson · #**889** 04/20/2006, 11:03 AM

Quote:

Originally posted 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 · #**890** 04/20/2006, 11:46 AM

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 · #**891** 04/20/2006, 12:04 PM

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

jnarowe · #**892** 04/20/2006, 12:36 PM

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

weatherson · #**893** 04/20/2006, 01:14 PM

Quote:

Originally posted 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 · #**894** 04/20/2006, 01:37 PM

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 · #**895** 04/20/2006, 02:11 PM

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

rufio173 · #**896** 04/20/2006, 03:41 PM

Quote:

Originally posted 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

rufio173 · #**897** 04/20/2006, 03:52 PM

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 · #**898** 04/20/2006, 04:05 PM

Quote:

Originally posted 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 · #**899** 04/20/2006, 04:47 PM

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 · #**900** 04/20/2006, 05:44 PM

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?