5' Skimmer Build in Progress

[spazz]

i dont think you will ever find the quality of small bubbles and the quanity of them either. not in an air stone. i was working on the same thing as you and ended up scraping the whole thing because of bubble size. now im doing this instead.


http://reefcentral.com/forums/showthread.php?s=&threadid=732601&perpage=25&pagenumber=1

 

[tinygiants]

spazz,

I have been following your threads. You put out some nice quality DIY. In parrallel to this skimmer, I am developing a spreadsheet that mathematicly models the skimmer.

Of course it all means nothing if the skimmer does not work. The calculator is geared towards a counter curent air stone skimmer, but some of the math works for all designs irrelevent to the air injection system. For example, if you know the size of the tank, the ideal flow rate to feed the skimmer is calculated for you (based on Escobal). The 13% air saturation can be calculated if you know how long a bubble takes in the water column. (I secure the air source - and time how long bubbles take to reach the surface after I turn the air back on. I do this in static water. If you measure the air injection distance to the surface, it should be a reasonable bubble rise time.)

Dale

 

[spazz]

<a href=showthread.php?s=&postid=6384687#post6384687 target=_blank>Originally posted</a> by tinygiants
spazz,

I have been following your threads. You put out some nice quality DIY. In parrallel to this skimmer, I am developing a spreadsheet that mathematicly models the skimmer.

Of course it all means nothing if the skimmer does not work. The calculator is geared towards a counter curent air stone skimmer, but some of the math works for all designs irrelevent to the air injection system. For example, if you know the size of the tank, the ideal flow rate to feed the skimmer is calculated for you (based on Escobal). The 13% air saturation can be calculated if you know how long a bubble takes in the water column. (I secure the air source - and time how long bubbles take to reach the surface after I turn the air back on. I do this in static water. If you measure the air injection distance to the surface, it should be a reasonable bubble rise time.)

Dale

i tried to download that but it comes out as goop on my computer. what program do i need to open it with? im gald someone has the mathmatics of this down so i can try and get the air/water ratios figured out right. right now im just mesuring the hight of the water in the tank when the pumps are running and the hight in the tank when everything is off. its not exact but its close. the other thing to rember is that the bubbles in a recirculating skimmer cycle around in the tank.

 

[slc]

Can you post info about the water flow meter? How to use, where to order?

Have you considered a diy wood air diffuser like the one here.
http://www.hawkfish.org/snailman/kwairstone.htm

A quote from this site: "This DIY project will show you how to make an awesome wooden air diffuser. This diffuser not only has more "bubble producing surface area (BPSA)" than several conventional 6" wooden air diffusers but also has less backpressure. Thus, when this air diffuser is used more air will be introduced into the skimmer and the bubbles will be smaller. The air diffuser can be made from any size solid block of Basswood.

You can also get basswood from hobby stores who sell model train supplies. I ordered a block on ebay for $10 that made about 80 airstones.

 

[tinygiants]

excel

 

[tinygiants]

in my recirc, I am not drawing in bubbles. I get the water from the clean water in the bottom.

 

[tinygiants]

I got these from a seller on ebay. Flow Meter

I am using 3/4" ID hose right now, but they can be plumbed with pipe. The threads are 3/4" NPT male.

My install is still temporary. I am adding a bubble vent pipe to my overflow system. I am also waiting on a new air pump and stones. Then I can finalize everything.

Dale

 

[ChemE]

Dale,

I can't wait to see how the new airstones and air pump perform. I'm also becoming curious in melding our ideas about skimmer design with the work spazz is doing with the sequence dart needlewheel + air pump. I can't help but wonder if spazz's work could be adapted to an eheim needlewheel for gentle recirc without the airstones. Just thinking outloud. Keep up the good work; we're all watching.

Chris

 

[spazz]

<a href=showthread.php?s=&postid=6385985#post6385985 target=_blank>Originally posted</a> by ChemE
Dale,

I can't wait to see how the new airstones and air pump perform. I'm also becoming curious in melding our ideas about skimmer design with the work spazz is doing with the sequence dart needlewheel + air pump. I can't help but wonder if spazz's work could be adapted to an eheim needlewheel for gentle recirc without the airstones. Just thinking outloud. Keep up the good work; we're all watching.

Chris

im not using any air stones in my test dart test stand. im force injecting the dart its self with the sweetwater pump. the airstones make too large of bubbles. but the dart makes super small bubbles.

 

[piercho]

SLC,
the KW diffusor from Snailman's site works very well, IMO/IME. I used 2" X 2" X 2" ones for a 4" CC skimmer. I used a KW diffusor for over 12 months continuous operation at a 5' injection depth. The diffusor got skanky-looking but continued to produce small bubbles at low back pressure. I did pre-filter the compressor air through a HEPA filter, this may have prevented particles from clogging the wood pores. There are considerations with the KW. You need to have the panes cut ahead of time, soak the wood overnight, and assemble the diffusor immediately before you start to use it. The diffusor needs to be kept in fairly constant operation and has to be kept wet.

The KW performed much better than a 6" ceramic diffusor I tried, with much lower back pressure. When Mojoreef was assembling his monster CC skimmer on Reef Frontiers, we talked about diffusor choice. He said he thought that the new fine pore sold by AES was better than the KW. In the time since then I haven't had a chance to get some of the fine pore diffusors and make a comparison.

But regardless, the KW diffusor is an effective and economical diffusor, IMO. You can buy a big block of basswood, enough to last a lifetime, for a few bucks off ebay.

 

[JC Pollman]

piercho: what air pump are you using?

 

[ChemE]

<a href=showthread.php?s=&postid=6386292#post6386292 target=_blank>Originally posted</a> by spazz
im not using any air stones in my test dart test stand. im force injecting the dart its self with the sweetwater pump. the airstones make too large of bubbles. but the dart makes super small bubbles.

Spazz,

Yup; I'm keeping up with that thread and understand that. What I'm thinking out load about is using an eheim needlewheel in a wide recirc loop to provide gentle recirculation. The needlewheel would be force injected by a sweetwater airpump as per your thread. This would give us the tiny bubbles we are wanting from the fine pore airstones and the gentle recirculation that was proposed on the skimming principles thread. Keep up the good work with the dart needlewheel; I'm carefully monitoring that thread as well as this one and a few others.

Chris

 

[spazz]

<a href=showthread.php?s=&postid=6391408#post6391408 target=_blank>Originally posted</a> by ChemE
Spazz,

What I'm thinking out load about is using an eheim needlewheel in a wide recirc loop to provide gentle recirculation. The needlewheel would be force injected by a sweetwater airpump as per your thread. This would give us the tiny bubbles we are wanting from the fine pore airstones and the gentle recirculation that was proposed on the skimming principles thread. Chris

are you going to have the sweetwater pump hooked to the air stones, and then have the eheim suck up both air and water? or were you thinking of pressure feeding the eheim to create the fine bubbles?
if you plan to force feed the eheim pump like i am you will need 6 pumps to get the amount of air injected into them. they are way too small of a pump to force feed them. thats why the dart is such a great pump for this. its large and can handle the cfm's that the little pumps cant.

 

[areze]

well the small pumps would cavitate(if Im understanding him right.)

I have a eheim 1260 and a maxijet 900 that Im going to mess with, try shooting the maxijet into the eheim, with the air injected in the middle. see what that does. and if it works, fit a needle wheel to the eheim and maybe...

the dart is a big pump, and might be nescessary for a skimmer such as yours spaz. I mean just straight up thats huge lol. but for some, the 400w of the dart, and the flow would make most home sized skimmers explode . see if we cant try the same idea with less flow. I think if I tried to just inject the air into a ocean runner like you are into a dart, Id manage to even cavitate a needle wheel that small.

 

[piercho]

JC,
part of the output of a Medo AC602 linear piston air compressor. The rated output is 1.5 CFM at 5'. I don't know how much of the output I was using, I never measured CFM to the skimmer. I had another Medo powering a lift and a RCSD on a common header. The compressor for the skimmer was tied into the common air header via a 1-way flow valve, and all the excess air from the skimmer compressor went into the common air header.

I trimmed the air input to the skimmer by putting a ball valve on a T toward the skimmer, and a needle valve on the other side of the T towards the air header. I would set the needle valve wide open and then coarse adjust the skimmer input with the ball valve. I then used the needle valve to make a final fine adjustment. You can adjust the air pump output by placing a single needle valve between the pump and the skimmer. IME this bypass method works better than placing a single needle valve in line with the skimmer. The foam head height is more controllable, IME.

This is the best CC skimmer thread I've seen. A much more thorough research into the characteristics than I made. Its illuminating to see someone predict the characteristics, then see what they get real world. I broke my last air skimmer when we moved this fall. I was waiting to build a new one because there was some design changes I wanted to work out. There's been some good ideas come out of this thread.

 

[spazz]

piercho are you using air stones and the needle wheel?

 

[spazz]

<a href=showthread.php?s=&postid=6392007#post6392007 target=_blank>Originally posted</a> by areze

for some, the 400w of the dart, and the flow would make most home sized skimmers explode .

the dart pumps only run 160 watts.as a regular water pump. and it all depends on what size body you put this pump on. if i were to build a body much like the bubble kings are, it would work for a 200-500gallon system, if you didnt use the air pump. then it would only be about 140 watts and give you about 90 scfh of super fine bubbles. the only time you need to "supercharge" the dart needle wheels is when the head presure get too great that the pump wont suck sufficent air to be cost effective. then an air "supercharger" is needed. if you think about it, the ocean runner's are 65 watts. the sedra 9000's are 90 watts. the dart sucking air on its own is only 140watts. thats not bad considering your getting 3 times the air input to the pump. its alot more effecient than a magnetic drive pump.
look at the numbers that deltec has posted on there site. then add hem up and compare them to the darts numbers.

 

[piercho]

No, I used a standard 4" air skimmer arrangement, pretty much as shown in the Snailman design. The reaction chamber was 5', with the neck and collector the whole thing was close to 7'. I haven't used a needle wheel skimmer.

 

[spazz]

<a href=showthread.php?s=&postid=6392101#post6392101 target=_blank>Originally posted</a> by piercho
No, I used a standard 4" air skimmer arrangement, pretty much as shown in the Snailman design. The reaction chamber was 5', with the neck and collector the whole thing was close to 7'. I haven't used a needle wheel skimmer.

what kind of stones are you using? what is your bubbles size like?

 

[piercho]

Just go back a few posts. Someone was talking about KW diffusors. I said that I had used KW diffusors and found them to be effective: long lasting with very low backpressure. Bubble size is the same as for a limewood or basswood diffusor. A KW diffusor is a hollow box made out of basswood. Construction instructions, along with pictures, use to be on Snailman's website.

When I said needle valve, I was talking about a valve for making very fine adjustments to air flow. Trying to trim an air skimmer with a ball valve is very difficult, IME.