Pico Skimmer Design

[Donya]

Wasn't sure if this should go in the DIY section or not since it's kind of a work in progress, and I'm just curious what y'all think about this since...I'm out of improvement ideas. I know skimmers arn't popular on picos, but in case anyone really wants one and doesn't care about how it looks, I managed to put one together for around $5 in materials with some airline tubing, a tupperware cup, hot glue, and a couple of valves to regulate airflow...

A - air line in and connector to regulate airflow
B - air line out and connector to regulate airflow (optional)
C - collection cup
D - airstone/bubble production
E - tube for foam production

The valve at B was originally just a hole punched in the top, but it had two problems: it got plugged up with water frequently (causing pressure buildup...amazing the effect 1 drop of water could have on internal pressure) and it whistled sometimes. About 1" of regular size airline before the valve solved the problem, since water can't splash up to the valve height and won't affect something with the diameter of airline tubing in the same way as a pinprick hole in the top.

The tube for foam production can be made out of anything...even large canister-filter-style tubing would work. I used a sheet of thin plastic and glued it together.

Here's a picture (from a bad angle unfortunately) of the thing in operation:

It collects stuff in the cup at a pretty decent rate and as completely filled my needs despite the fact that I havn't even gotten the ideal type of airstone yet. But...there are a couple of problems I see in the design:

1. It's very touchy about where the waterline is. The air flow has to be adjusted pretty exactly with changes in waterline, or foam can shoot out the top or bottom. Waterline going down just looses power (not catastrophic), but waterline going up too much will make the collection cup fill water/foam/etc. and eventually cause stuff to come out in some way, either out the top or bottom since the pressure gets messed up. I am not sure how to solve the waterline sensitivity with an air-powered design...if anyone has input it would be appreciated.

2. General inefficiency for skimming compared to designs of larger skimmers. It could be improved by placing a divider in the tube to have a distinct "in" and "out" for the water, but I am doubtful whether it would really have all that much effect. It does work currently, and picos just really arn't all that big anyway...

3. UUUUGGGLYY! There may be some clever way to make it out of tank, or hide it...or just make it out of more sightly materials. For a few more dollars I'm sure it could be made a lot less tacky-looking.

 

[bunjiweb]

Looks good. You would find it alot more efficient if you use a ceramic or wood air-stone to make the finest bubbles possible.

Ben

 

[petey Z]

looks like something nice to have, if u dont have to spend a heafty dollar on one, how do u make that if u dont mind me asking??

 

[Donya]

The stores were all out of wood ones...it is still on my to-get list. One store had ceramics in stock, but I didn't know those would work. I better go snatch one before the people who baught up all the wood ones realize that

EDIT: missed the second post, sorry. I will draw up some better diagrams showing what it looks like put together since the photo of the finished one was well...yuck lol. Can't really tell much from that. It's a very simple design though, took me about 15 minutes to stick together.

 

[Donya]

See if this helps: http/www.angelfire.com/va/myevolution/sn...ico_skimmer.doc

You may need to right click and do a save-as to get the file. Wish I had a better server for that stuff but right now I don't, sorry.

 

[Donya]

Ceramic/wood won't work...other than the fact that I can't get a hold of one that is small enough--I know they exist but they are all out still---I tried a synthetic one that is inbetween bubblesize of a regular grit-style airstone and a ceramic one, and I couldn't get the foam under control. The critical pressure to produce sufficient bubbles was too high (more pressure required for a more dense material). When bubbles happened foam shot out the top way too fast and filled the cup. On a bigger design for something like 10 gallons it could work, but not on my littler skimmer. I'll leave the 10-gallon design up for someone else to try, since I don't have the ability to test one on that scale. Mine works well enough with the regular airstone, just takes about 5-10 minutes after shutting off to warm up and build up a good thick foam. Once the foam is built up, it is consistent as long as the air keeps pumping in.

On the plus side, I took the synthetic fine-bubble stone and tried using it to drive a UGF in a freshwater tank, and got pretty spectacular results there. It's as good as having a water pump fixed to the UGF tube, not bad at all.

 

[Lynden]

Pretty good, pretty good.