5' Skimmer Build in Progress
- Thread starter tinygiants
- Start date
tinygiants
New member
Thanks.
AES for the uniseals.
The three stone manifold is what I am going to use. It is the one that resembles a pitchfork.
Dale
AES for the uniseals.
The three stone manifold is what I am going to use. It is the one that resembles a pitchfork.
Dale
BeanAnimal
Premium Member
Dal that wouldn't be a christmas sweater (the kind you wear to make the wife happy) your wearing in that photo would it?
tinygiants
New member
Yes and NO
It was a Christmas Gift from her Mother. It is a sweat jacket to go with the sweatpants I got also.
I just finished installing my floatswitches. I should have done it a long time ago. It was very simple really. I did just like http://www.floatswitches.net/autotopoff.html says, except I used a gangbox and a regular outlet. I plugged the power for my return pump into my switched plug in the basement. I installed the relay in the gang box as well. I ran two 12 volt wires up to the display tank where the switches are installed in the overflow tower. For a power source, I attached to my 12 volt bus bar that is installed in my canopy for my moonlights. They run 24/7. A quick test and all was well. A total blockage and it shuts down with an extra inch to spare. There is also a backup switch.
Now I can play with my overflow lines feeding the skimmer without fear.
Maybe I will post a thread about it with pics later.
Dale
It was a Christmas Gift from her Mother. It is a sweat jacket to go with the sweatpants I got also.
I just finished installing my floatswitches. I should have done it a long time ago. It was very simple really. I did just like http://www.floatswitches.net/autotopoff.html says, except I used a gangbox and a regular outlet. I plugged the power for my return pump into my switched plug in the basement. I installed the relay in the gang box as well. I ran two 12 volt wires up to the display tank where the switches are installed in the overflow tower. For a power source, I attached to my 12 volt bus bar that is installed in my canopy for my moonlights. They run 24/7. A quick test and all was well. A total blockage and it shuts down with an extra inch to spare. There is also a backup switch.
Now I can play with my overflow lines feeding the skimmer without fear.
Maybe I will post a thread about it with pics later.
Dale
BeanAnimal
Premium Member
Any fear of it oscillating if there is a partial blockage? Could be pretty hard on the return pump.
tinygiants
New member
I agree it could be hard on the pump, but I only expect it to kick in if I have a problem. So far that problem was me
tinygiants
New member
Well here is the results of my testing:
Bubble Rise Height = 48.00 Inches
87% of bubble Height = 41.76 Inches
Air Volume to get 100% of Height = 35.00 SCFH
13% of air water column = 0.09 Feet3
Air Dwell = 9.67 Seconds
Air Bubble Rise Rate in Current 4.96 Inches/Second
Calculated Air bubble Rise Rate Standing Water = 5.55 Inches/Second
I removed the riser cones. I measured from the top of the air stone to the bottom of the foam tower. This was 48 inches. I calculated 87% of that height to be 41 3/4 inches. I adjusted my hartford loop to drain the skimmer body to that point. I then set up the recirc pump to match my total intended flow rate (recirc + feed). I then adjusted the air feed volume until I had the water and air column to the 48 inch mark. It took 35 SCFH to maintain that 13%. I was able to calculate an "average" air dwell time based on volume. This also allowed me to come up with a bubble rise rate that models the entire air column based on volume.
My next step will be to lower the water level even more and do it again. If my assumptions are correct, all the data should be unchanged. The air should escape the water column at the same rate. The dwell time will be lower as a function of rise height, but the air volume needed to raise the column to the new 100% mark should be the same.
Dale
Bubble Rise Height = 48.00 Inches
87% of bubble Height = 41.76 Inches
Air Volume to get 100% of Height = 35.00 SCFH
13% of air water column = 0.09 Feet3
Air Dwell = 9.67 Seconds
Air Bubble Rise Rate in Current 4.96 Inches/Second
Calculated Air bubble Rise Rate Standing Water = 5.55 Inches/Second
I removed the riser cones. I measured from the top of the air stone to the bottom of the foam tower. This was 48 inches. I calculated 87% of that height to be 41 3/4 inches. I adjusted my hartford loop to drain the skimmer body to that point. I then set up the recirc pump to match my total intended flow rate (recirc + feed). I then adjusted the air feed volume until I had the water and air column to the 48 inch mark. It took 35 SCFH to maintain that 13%. I was able to calculate an "average" air dwell time based on volume. This also allowed me to come up with a bubble rise rate that models the entire air column based on volume.
My next step will be to lower the water level even more and do it again. If my assumptions are correct, all the data should be unchanged. The air should escape the water column at the same rate. The dwell time will be lower as a function of rise height, but the air volume needed to raise the column to the new 100% mark should be the same.
Dale
tinygiants
New member
Yes I have had skimmate. Yes it was nasty. No I did not take pics. I need to redo the collection cup. I am not happy with it. After the new cup, i can dial the whole thing in.
we demand pics 
if you are successful you give me hope.
on a side note, I created a 2" diameter disk with slats cut in the edges, unfortunatly my unknown brand powerhead did not turn it. I believe because it is not centered enough. the unit itself is basicly a disk and has essentially no resistance, but it doesnt even try to spin, just twitches.
it would be better served as a direct drive to an actual electric motor out of the water, not with a magdrive. however Im not sure what would offer the long term durability at 1000RPM or so. any suggestions? I might mount it to a drill to test and see if it works and is worth pursueing. Ill do that tomorrow.
if you are successful you give me hope.on a side note, I created a 2" diameter disk with slats cut in the edges, unfortunatly my unknown brand powerhead did not turn it. I believe because it is not centered enough. the unit itself is basicly a disk and has essentially no resistance, but it doesnt even try to spin, just twitches.
it would be better served as a direct drive to an actual electric motor out of the water, not with a magdrive. however Im not sure what would offer the long term durability at 1000RPM or so. any suggestions? I might mount it to a drill to test and see if it works and is worth pursueing. Ill do that tomorrow.
tinygiants
New member
Pics of skimmate?..... That is one I never understood. Why do people want to see my trash? Maybe. Only after I get it all dialed in and produce a thick pudding like substance.
Dale
Dale
eh skimmate doesnt interest me. though I did just remember you used PVC, not much to see in a pic. I just wanted to see a wide out shot of the bubbles, close up the aspect is hard to really tell size vs distance from the lens. you said the bubbles were small as any needle or beckett, but I the photos are so zoomed in they look pretty big, compared to spazz's NW and such. but that could just be them zoomed in a lot.
tinygiants
New member
<a href=showthread.php?s=&postid=6441425#post6441425 target=_blank>Originally posted</a> by tinygiants
This is a fine pore stone horizontal. I also stood them verticle. Thje pic did not come out. I will be standing mine verticle.
The above photos are intended to show the bubble quality. The item in the pic is a pippette from a test kit. The drip nozzle on the end is every bit as small as a sewing pin.
Based on my quick little test, I will be adding the 3rd stone. I saw a difference in teh bubble quality as the volume increased. At the worst end I just had more of the larger bubbles, and I believe even they are as good as a NW's give. At best it was a large quantity of the microbubbles. The stones verticle produced bubbles from all surfaces.
Dale
Look at the tip of the pipette. It is as small as the head of the needle in Spazz's post. I feel that the quality of the bubbles are a match.
Dale
JC Pollman
Premium Member
Great job so far - and needless to say, I am very happy it is working well - always better when all that time invested actually produces a workable item 
And since you seem to be satisfied with the skimmer, I am even more motivated to make my own based on your plans. If you do not mind, I have a few questions:
Question 1: the manifold you built looks like PVC. I thought the air stones used CPVC fittings. If so, why did you use PVC instead? The reason I ask is because the CPVC pipe fittings are smaller and might make a smaller manifold. Also, are you using 1/2 inch fittings?
Question 2: can you give us a description of the air pump to stone connection? In particular: how did you connect the 1/4 inch barb up to (C)PVC pipe, and how do you have the manifold connected inside the skimmer so you can remove it for cleaning when it needs it? Also, at what height do you have the air line enter the skimmer?
Question 3: the right air pump: since the 11 was too small, and the 19 is overkill, I am thinking the 15 might be the best pump for this skimmer. You are using .58 CFM, and eyeballing the chart, the 15 puts out .75 CFM and the 19 puts out 1.66 CFM at 2 psi. Of course there is the question of durability when using the 15 at near max output.
Sorry for all the questions, but I would rather not have to reinvent the wheel
And since you seem to be satisfied with the skimmer, I am even more motivated to make my own based on your plans. If you do not mind, I have a few questions:
Question 1: the manifold you built looks like PVC. I thought the air stones used CPVC fittings. If so, why did you use PVC instead? The reason I ask is because the CPVC pipe fittings are smaller and might make a smaller manifold. Also, are you using 1/2 inch fittings?
Question 2: can you give us a description of the air pump to stone connection? In particular: how did you connect the 1/4 inch barb up to (C)PVC pipe, and how do you have the manifold connected inside the skimmer so you can remove it for cleaning when it needs it? Also, at what height do you have the air line enter the skimmer?
Question 3: the right air pump: since the 11 was too small, and the 19 is overkill, I am thinking the 15 might be the best pump for this skimmer. You are using .58 CFM, and eyeballing the chart, the 15 puts out .75 CFM and the 19 puts out 1.66 CFM at 2 psi. Of course there is the question of durability when using the 15 at near max output.
Sorry for all the questions, but I would rather not have to reinvent the wheel
tinygiants
New member
<a href=showthread.php?s=&postid=6450400#post6450400 target=_blank>Originally posted</a> by JC Pollman
Question 1: the manifold you built looks like PVC. I thought the air stones used CPVC fittings. If so, why did you use PVC instead? The reason I ask is because the CPVC pipe fittings are smaller and might make a smaller manifold. Also, are you using 1/2 inch fittings?
The manifold is pvc. The stones I ordered came with threaded PVC nipples it appears. I know that stainless and cpvc are available. I am using 1/2" fittings. CPVC is smaller, but it would need to be cut down, also the corner fitting is not available local in cpvc.
Question 2: can you give us a description of the air pump to stone connection? In particular: how did you connect the 1/4 inch barb up to (C)PVC pipe, and how do you have the manifold connected inside the skimmer so you can remove it for cleaning when it needs it? Also, at what height do you have the air line enter the skimmer?
I used a threaded X slip 90 (not glued). I then used a 1/2 to 1/4 bushing to get to my flowmeter. Flowmeter uses a barb as the inlet.
Inside the chamber I have a stub of 1/2 pvc comming through a uniseal. I use a coupling and a 90 (not glued) to get to the manifold. The only pieces inside the body that are glued are the manifold itself
Question 3: the right air pump: since the 11 was too small, and the 19 is overkill, I am thinking the 15 might be the best pump for this skimmer. You are using .58 CFM, and eyeballing the chart, the 15 puts out .75 CFM and the 19 puts out 1.66 CFM at 2 psi. Of course there is the question of durability when using the 15 at near max output.
Sounds reasonable. Doing it again, i would buy the 19 first. Yes the chart may say I can get less, but I am Tim The Tool Man trained.
Dale
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