DIY Skimmer????

[WarDaddy]

Anyone ever make and use one of these?


DIY Skimmer (http://saltaquarium.about.com/gi/dynamic/offsite.htm?zi=1/XJ&sdn=saltaquarium&zu=http%3A%2F%2Fwww.hawkfish.org%2Fsnailman%2Fsnailmandiy.htm)

If I ever build my basment system I am looking at 2 300 gallon tubs, 1 150 Gallon Sump and 2 of the 6" skimmers from above, 5 foot tall.

I want to run the whole system off air, with exception of the pumps to move water through the skimmers. Maybe a couple modded Maxijets for water movement.

How well do they work? (The Skimmers) How much did it cost to build?

[raaden]

I built something very similar, and it worked very well. Also Rick Rottet is using something very similar en masse in his greenhouse. Mine cost about about $65 but I had to tear mine apart a time or two and rebuild part of it until I got it just right

A couple of other things to consider
Part E should be turned so the elbow is facing down. This will give you less bubbles out of the unit.
make sure you leave yourself a way to get to the airstone (don't glue it to the side like I did :eek: or you will never be able to change the stone)
If you layout your return piping carefully, and are returning water to the same height as the output you can also use an airlift for water movement through the skimmer as well. Unless you want to use a pump.

[WarDaddy]

REALLY? I am struggling with this in my mind. IF the input for the Skimmer 5 feet high, and the Sump water line is 2.5 feet above the ground, you can use air?????

I would really love to see how this works, because I would love to just buy on big air pump and leave it at that for all my Circulation and Skimming.

Wow! Tell me more!

--Bryan

<a href=showthread.php?s=&postid=8082635#post8082635 target=_blank>Originally posted</a> by raaden
If you layout your return piping carefully, and are returning water to the same height as the output you can also use an airlift for water movement through the skimmer as well. Unless you want to use a pump.

[WarDaddy]

With this in mind....

How much airpump is needed?

I would need to drive water for the following
Circulation
2 x 300 gallon tanks (4 Lifts?)

From Sump
2 lifts per tank (4 Lifts)

Several misc tanks (4 lifts)

All lifts 1.5" PVC?

Then I would need to power the Skimmer
2x 5 foot tall 6" PVC (1 lift and 1 airstone each)
2x 5 foot tall 4" PVC (1 lift and 1 airstone each)

I am looking at the smallest, LPH26, is that enough?

[raaden]

Couple of things going on here.

First thing is think of an airlift as just another type of pump. It just uses air bubbles instead of an impeller just like a bladeless pump using an oscillating disk instead of an impeller. Each type of pump has situations it handles better and worse than another. Unfortunately an airlift, contrary to its name :p , is not very good at lifting water above the water line of the Source Tank . That is a key here. Since an airlift is considered an open system (since the air is not contained) the lift doesn't care about the tank it is putting the water into only about the pressure the lift is getting the water from is providing. Once you understand this point you can begin to use airlifts for much more than just rolling water in a simple tank. The basic point is that as long as the water level in the skimmer is at the same height you want to return the water too (or slightly above or below) you can do it just fine with an air lift.

Second: the outlet pressure (depth, obstructions, etc.) on the end of the tube where the air enters the water must be the same for all outlets sharing a common air source to get consistent airflow. This means that if you are going to try to use a single pump to run both the skimmers and the airlift you are going to have next to no bubbles in the skimmers. If you put the outlet of tubing for the airlift a 2' depth, and put the the outlet of the tubing for the skimmer at 5' depth the air is going to want to go through the airlift and not overcome the added pressure of the deeper skimmer outlet. Add an airstone obstruction to it and it becomes even more pressure to overcome. The worst case scenario is that you will flood the tubing in the skimmer and will get nothing from it.

If you get this part then I can explain what I would suggest. If not pm me and I will give you some diagrams to try to explain it.

You will need atleast 2 pumps. One of a vane or blower type for high volume low pressure air. These you will use on your airlifts since they are not as deep as the skimmers. they should also be pretty big but they don't have to be industrial sized, you will be surprised how much flow you get from an airlift and a moderate amount of air. The other must be some sort of a positive displacement type, either a diaphragm type in which you could use one for each skimmer or a smaller linear piston pump in which you could use one for both skimmers. The only problem with the LPP is that they are pretty noisy and and pretty large compared to some smaller diaprhagm style. either way for two skimmers you don't need a whole lot of air so I would say look for a small lpp or a medium diaphragm.

for the layout you will need to think about your water levels for your source tanks. When you are moving water from one source to another it is best to output the water to the surface of the recieving tank. You may also want to think about what you are going to do with the sumps. do you really need them can you mount them at the same level as the main tanks. In order to do lifts between all of them this is truly the key.

Lastly you will need to make sure you size your overflows or feed mechanism properly. Airlifts can fluctuate wildly with the amount of flow they provide based on any number of factors so make sure you have lots of wiggle room in your calcs so you don't end up dumping water or overflowing a tank.

That is just off the top of my head, I can go into more detail or provide more explanation if you need it

[WarDaddy]

So could I get a Lift to move a good amount of water up 12 inches?

I would like to have my sump level at least 12" under the level of the tanks. This would allow me to have a gravity overflow from the tank to the sump. I would like the sump to make water changes easier, top off control easier and keep the bubbles from the skimmer return out of the main tanks.

IF I can not drive the water up 12 inches with air, I will then use a Pump. I would like to move 600 to 900 gallons an hour though the lifts from the sump. Then I would use additional lifts in the mian tanks just for circulation.

I think I will use a pump to move water through the skimmers.

Here is a dirty diagram of wha tI am thinking.

http://gifford-family.smugmug.com/photos/93496165-M.jpg

[WarDaddy]

I have been thinking more about this... Would this work?

http://gifford-family.smugmug.com/photos/93564743-M.jpg

NOTE: the green should be return to Sump

My thinking here is that if I use the weight of the sumps water to prime my airlifts I should be able to inject the air deep in the tube, well below the sumps surface level, and get a good amount of water to rise up 1 to 3 feet.

To get water into the main tank, it would only need to rise 1 foot, no biggie. To get the water into the Skimmer, it would need to rise about 3 feet above the surface of the sump water, a bigger challenge.

Lets assume I can raise the water the 3 feet, which I do believe I can achieve. Would having the air lift feeding the skimmer cause a problem with skimmer performance?

Here is where I go some ideas....

Skimmer design (http://www.hawkfish.org/snailman/diy6inskimmer.htm)

Air lift powered tank (http://forum.marinedepot.com/Topic34197-13-1.aspx?Highlight=airlift)

What do you guys think?

NOTE: I would need a pump for the Skimmer lift, a pump for the Skimmer bubble, a pump for the Tank Lifts, and a Pump for the Tank Circulation Lifts... But power wise, this is way more effecient than Mag pumps.