air skimmer for 300g setup

[tommyp]

Hey all,

After a few years of running a beckett on my smaller tank. I am upgrading my tank and skimmer. I am intriqued by the linear airpump method. My skimmer/sumps are in my basement so noise is not an issue for me. I just want something that will skim the heck out of the water.

I have thought about needlewheel or adding another beckett head to my skimmer and a larger pump but just can bring myself to build ether.

So what do I need to get this skimmer to reality. I have built a few skimmers so the Diy is not a prob.

What size tube should I shoot for? it looks as though a mixing chamber is necessary on the smaller skimmers. I don't think I am going to be able to afford 12" tube.

Is there a recipe out there for a good total diy air skimmer?

Thanks

Tom

 

[tommyp]

To clairfy further I am thinking of using the LT-19 and the 150cp airstones. What size mixing box would I need? and tubing? is 6" going to be to small? How high? 48" 60?

Thanks

Tom

 

[tommyp]

Duh! I was just reading mikes new skimmer thread again. Saw the specs for the 3-500 one. Will try to cronicle my setup.

Tom

 

[big t]

Sounds Cool Tommy, we will be here to see what you go ahead and do. I will be interested to see the results.

 

[mojoreef]

Tommy before you start your planning for the skimmer take a peek at the skimming 101 thread in Anthony's forum. It has the math you will need to figure out size, air and throw water. Check it out and let me know if I can help


Mike

 

[tommyp]

I checked out the skimming 101 thread. I was a little confused about the skimmer size. doest the internal size have anything to do with the dwell or feed rates?

I read that you measured dwell by timing the bubbles and that you calculated total turnover by the formula of (size/feed)x 9.2 and then you said that the minimum should be 2X a day and yours came out at 15 hours. that wouldn't give you 2x but it would probably be close enough

so for a 300 i am looking for (300/x)9.2=12hrs of turnover. so to reach back to hs math i get

300/x=1.3
300=1.3x
230=x

230gph through the skimmer. easy enough to do.

What I am thinking is to make the skimmer like donw's but use a large square mixing chamber. I have a long 6" extenstion that I had made for my previous beckett so I could bolt that on top of the mixing box. It has the old collection cup and everything so it would be pretty easy to just adapt it for now so i can get something up and running. If I need to tweek/make new later I can do so.

What is the best way to get the extenstion to seal on to the box? Put an oring on the head of the bolt inside the skimmer? Like a boat hatch. I have always glued my skimmers together and it is only bolted in the foam area so there was little leakage. This joint will probably be in the same way but I want to make sure I have as little seepage as possible. Maybe tap the box and silicone the threads?

Also how is the water exit being controlled. I am a big fan of hartford loops but I am not sure how high the water level will be in this skimmer. it seems like mojos is very low in the box don's I think was a bit higher but my sump lip is about 33" off the floor. So it will limit my skimmer height if I have to raise it 25" just to get it to drain over the sump. My basement ceiling is low. Damn 1877 building codes! better yet damn nutrition in 1877.

I am thinking a 12x12x?30? box on the bottom 20" 6"dia riser bolted to that. Collection cup ontop of that. at least for now. I probably would go through the extension bolts to futz with the airs stones and have a bulkhead some where to feed air into the stones.

I am not sure where I would place the input probably at the top side of the mixing chamber as I don't like drilling tube so much.

and then put the output down near the bottom possibly a baffle between it and the stones.

What ya think?

 

[mojoreef]

I checked out the skimming 101 thread. I was a little confused about the skimmer size. doest the internal size have anything to do with the dwell or feed rates?

Dwell time is a function of the skimmers diameter and feed rate.

What is the best way to get the extenstion to seal on to the box? Put an oring on the head of the bolt inside the skimmer? Like a boat hatch. I have always glued my skimmers together and it is only bolted in the foam area so there was little leakage. This joint will probably be in the same way but I want to make sure I have as little seepage as possible. Maybe tap the box and silicone the threads?

Either route a grove on both sides and install a O ring, or use a gasket.

it seems like mojos is very low in the box don's I think was a bit higher but my sump lip is about 33" off the floor. So it will limit my skimmer height if I have to raise it 25" just to get it to drain over the sump.

Take a peek at version 2 of that skimmer. I reconfigured it and have the whole skimmer as the mixing chamber right up to the neck,much better.
http://www.reeffrontiers.com/forums/showthread.php?t=7590

I am thinking a 12x12x?30? box on the bottom 20" 6"dia riser bolted to that

Would the neck be on top of the riser tube?? Let look at the numbers. If the neck was on top of the riser tube you would fill the square with water and also the tube. This would leave you with a skimmer compacity of about 21 gallons. Of that 21 gallons about 20% of it should be air, so that would leave 16.8 gallons of water. Now feeding the skimmer at a rate of 230gph would mean that it would take about 4 mins to flow through that skimmer, that is an awesome dwell time!!!!!!!.
Now with a air dwell its going to take about 10 seconds for the air bubble to rise from the stone on the bottom to the neck. this would include the water resistance and possible some circular motion with the flow. So your bombardment rate would be 262 seconds of water dwell divided by 10 seconds of air dwell = a bombardment rate of 26 which is again outstanding.
For air you are going to have to inject 4.2 gallons of air constant.

I am not sure where I would place the input probably at the top side of the mixing chamber as I don't like drilling tube so much.

Sure, I would just plumb it up a little bit into the round tube from the inside and then put a 45 on it to create a circular motion.

and then put the output down near the bottom possibly a baffle between it and the stones.

I would put it so that it comes via a elbow pointing down to the bottom of the box about 3 inches off the bottom. I dont think you need a baffle, maybe a mounting plate to hold the weight of the stones.

I think its going to be a good one buddy. Just make sure you get the right stones and air pump.


Mike

 

[tommyp]

Wow thanks Mike!

Even with a gasket or oring (I would probably use a rubber gasket) I would have to drill though the top of the mixing box. So on the inside of the box I would have the bolt head but even when tightened water would still get by the head a bit. Right? or would it be watertight when tightened. On kayaks we would put orings between the bolt heads and the inside of the boat when bolting on the deckplates so that it wouldn't leak. Maybe I am just worring too much.

Yeah the neck would be ontop of the riser i believe it is 3"id. I think it is like 8" tall now but I can extend it or make it larger if necessary.

Any suggestions on the airpump? I was thinking of going with the lt-19 and then the 150cp's I would probably buy the pump from aquacave and then call aquatic eco for help because they want $36 more for the same pump.

Tom

 

[mojoreef]

The Lt air pumps are louder then some of the others that have been suggested here, so keep that in mind. On the oring I just used a router to put a small groove on either plate of the flanges, I put them about 3/4 of an inch on the inside of the bolts and dont have any leaks.


Mike

 

[big t]

The problem that Tommy is talking about mike is that he is trying to put a round peg into a square hole. So he dosn't have a outside edge to seal off and is concerned that the water is going to leak thru the the screw holes since there will be water under them.

Tommy here is what will make this easy. Make the flange large enough so that it covers the entire outside of the square. It can be square and make it large enough so that the screw holes will not be over the inside dimension of the skimmer body. That way you can move your screws outside the box and not have to worry about them leaking. You could also make it round this way and go w/ a o-ring and keyholes which make life a whole lot easier. HTH

 

[tommyp]

I am going to give it a shot trying to bolt to the round flange/riser tube that I already have to the box which I will start this weekend. If I have to oring the bolt heads it won't be that big a deal and that should seal it up fine. I'll post pics when I start building.

I have an uninhabited basement fish room so loundness isn't a big deal just that it has enough guts to do what I want. I don't want to buy a pump twice.

thanks for the help

Tom

 

[tommyp]

Wow it seems like forever since I started this thread.

I now have a Lt19 on the way and 3' of 12"dia Pvc coming as well. I am going to get some acrylic to cover the top and bottom of the tube. I have to order my stones yet. but the thing should go together really quick once I get the pieces.

Tom

 

[tommyp]

got the pump today

How do I plumb this thing? I assume I would use soft tube from the pump to a barb and then go 1/2 cpvc from there to the airstones. I could go soft to barb to speedfit/ 1/2" ro tube to some sort of bulkhead/uniseal then speedfit to the cpvc airstone manifold.

to put a bleed off valve in could I just use a speedfit valve teed into the line out of the airpump?

How would I fashion a filter for this thing? It has a barb input would i just search around depot for something i could rig up?

thank s

tom

 

[DonW]

How would I fashion a filter for this thing? It has a barb input would i just search around depot for something i could rig up?

thank s

tom

You just replace the whole black cover with a auto air cleaner. Just the cheap 4" chrome ones made for 2bbl carbs.

Don

 

[tommyp]

Great thanks Don! off to the autoparts store I go.

I was talking to a guy who runs one of these in his fw setup. he said not to bleed it but restrict the air to the stones with a speedfit valve between the pump and the stones. basically the same as ballvavling down a water pump. Does this make sense? or should I bleed off air to reduce bubbling?

Tom "my airpumps got a hemi" Preska

 

[mojoreef]

Tommy that is kind of hard on the diaphrams. I used to do it that way but ending up having to replace the diaphram to often.


Mike

 

[tommyp]

gotcha so will just bleed out.

Thanks mike!

 

[mojoreef]

Tommy if the soouund of it is to loud for ya you can make a little silencer, with cotton and carbon.


Mike

 

[tommyp]

I am sure it will be fine once I put the stones on it. I ordered them today along with everything I need to get the skimmer up and running. i ordered a needlevalve to be able to bleed air off. So hopefully by midweek everything will be here and I can start getting the show on the road.

Thanks for all your help mike

 

[tommyp]

Here is a pic of what I have going so far.

I am going to have to tap the acrylic in order to get the flange to work the way I need it to.

stones and parts should be here thursday