PDA

View Full Version : What is the best airstone for a protein skimmer?


electric130
06/09/2003, 11:29 AM
Just as the title says. I'm about to build an air-driven counter-current skimmer of sorts and was wondering what is the best kind of airstone to use. i know most people use the wood, but what brand and size did you use?

Looper121
06/09/2003, 11:33 AM
Balsa wood ones are the best as far as I know. As far as brands, i don't know, you could probably cut one yourself.

Angel*Fish
06/09/2003, 11:34 AM
Have you considered building a pump driven skimmer?

electric130
06/09/2003, 11:37 AM
Originally posted by mantisagogo
Have you considered building a pump driven skimmer?

yes i have, but i don't have the money to buy a pump large enough to drive the skimmer. plus the skimmers are louder and the pumps are louder than an air driven. for the amount of electricity and noise, air driven counter current skimmers are more efficient. this is what i'm thinking of building.

Snailman's 4" CC (http://www.hawkfish.org/snailman/diy4inskimmer.htm)

electric130
06/09/2003, 11:45 AM
Originally posted by Looper121
Balsa wood ones are the best as far as I know. As far as brands, i don't know, you could probably cut one yourself.

balsa wood or bass wood? i've heard of bass wood being used, but not balsa wood.

Sebastian
06/09/2003, 11:46 AM
www2.hawaii.edu/~delbeek/ff.html


I have had good luck with this design from Larry Jackson.

tag007
06/09/2003, 11:49 AM
I make my own out of bass wood.
I would suggest not using balsa. I have never had good success.. There are a couple of DIY wooden diffuser out there on the web, I have seen some pretty exotic ones.
I make mine by cutting with a fine toothed acrylic blade (because I am too lazy to change it), but anything with very little rake and alot of teeth (+80) i think should do. Remeber that this is a hardwood, even though it doesn't look like it. I make my about 5/8" square, ~2" long, drilled with 3/16" hole about 3"4 way down. Works real good. Better than anything you can buy in the store..
Tons of microbubles...

I got a huge chunk from local woodworkers shop for like 80 cents. Make about 20 of them at a time..

Just remeber, do not test in fresh water. I made this mistake and took me about two weeks to figure out that, was what my problem was.

-Tag

Looper121
06/09/2003, 12:11 PM
I have never made a BALSA wood one before. I used to frequent a shop where the owner made them. I must admit they looked pretty good, and the foam they made was even better.

What are teh disadvantages Tag?

Unresistible Blue
06/09/2003, 05:11 PM
I made the snailman DIY skimmer months back, and have been making and using the "KW Awesome Air Diffusers." I don't remember if the KW's post about his basswood design was on this board or Aqualink. I think it was here.

Why the recommendation not to test them in fresh water?

Blue

electric130
06/09/2003, 06:16 PM
Originally posted by Unresistible Blue
I made the snailman DIY skimmer months back,

what size did you make (3", 4", etc) and how tall was it? how does it work for you?

Originally posted by Unresistible Blue
and have been making and using the "KW Awesome Air Diffusers." I don't remember if the KW's post about his basswood design was on this board or Aqualink. I think it was here.

KW diffuser (http://www.hawkfish.org/snailman/kwairstone.htm)

do you have a table saw that you make them out of?

rbaker
06/09/2003, 06:22 PM
I used to use Limewood when I had a CC skimmer. I made my own. It's cheap and simple. Your local Woodcraft or carving store will carry it in large chunks...

JMO,

Ryan

electric130
06/09/2003, 06:35 PM
for those people who have used a snailman skimmer, do you think a 4" skimmer with the main body 22" tall (plus the throat and cup) will work for a 90 gallon tank? or is it not worth the time? that's about all i'd have room for.

outprowllin
06/09/2003, 08:14 PM
my two cents.......i use coralife 2.5/3 inch air stones .....they used to be lime wood but they now be bass......also use aquamedic stones in a pinch.......jaime

Unresistible Blue
06/09/2003, 09:07 PM
I used an 8" diameter pipe for the main body - about 4' long or so. All told, it stands about 7' tall. Works well, once I got an air pump with enough eumph (a Medo 0502).

Yes - you'll need a table saw to slice the basswood into thin pieces. I start with a 2"x4" basswood piece. If you get to the point of building them drop me an email and I'll give you the benefit of some of my trial and error in building them.

Blue

turtlespd
06/09/2003, 09:45 PM
From experience, what air drivin pump does eveyone recomend. I have also considered a air drivin skimmer. I have been through all the skimmers already and really just want to see how they compare to all the other types.

piercho
06/09/2003, 09:47 PM
Electric130: I'm using a 4" diameter CC skimmer per snailman's instructions. The total heigth is over 6' tall. My tank water level is 4'9" above the floor, I set the return at about 5' and drive enough air to generate the >1' foam head.

I'm currently using a 6" Rena Micro-Bubbler (Aquarium Pharmaceuticals) as a diffusor for this skimmer. The bubble size isn't as fine a basswood or limewood, but you get a lot of bubble surface area, so it's a trade-off. They are a bit spendy, i think around $6 each, but last a few months (6, or more).

Another option is KW's awesome air diffusor, a DIY diffusor. Snailman has directions on his website. You will need to buy a block of basswood (try eBay) and get it cut on a tool like a band saw to do this one. snail man says that this one will improve your foam head over using multiple air stones - that is, inject more and finer bubbles at lower backpressure. I haven't tied it.

One thing to consider before you undertake this is the air pump. Most diaphram air pumps sold for the hobby just won't, IMO, be able to produce a very good foam head heigth with a large, deep skimmer. I use part of the output of a Medo AC602 linear piston pump for mine. That pump could probably drive 2 skimmers the size of mine, or more. The air pump (or pumps!) needed to drive the skimmer will be the main cost of using a tall CC skimmer.

tag007
06/10/2003, 06:13 AM
I recommend not testing in fresh water because the surface tension is different, causing the bubles to combine, not giving you a good idea of what buble size you are actually producing.
I spent several weeks looking for a wood that would give me good bubles. I strated with basswood, but testing in fresh water gave me big bubbles. Went to oak, some tight pine, balsa, and the a couple more pieces of tighter bass until it dawned on me to run them in saltwater. Put one in my tank and was ****ed at myself to see millions of tiny little bubles..Luckly I do alot of wood work, so was out of my time more than anything.
BTW
All wooden diffusers sold in stores are marketed as "limewood". Lime wood = bass wood. I guess the British call it limewood, and to confuse the consumer, that is what it is sold as...
I would suggest looking for a tight smooth grained piece of bass wood, and use a fine toothed saw to get a nice clean, almost burnt cut.

AnnArborBuck
06/10/2003, 06:23 AM
Originally posted by electric130
for those people who have used a snailman skimmer, do you think a 4" skimmer with the main body 22" tall (plus the throat and cup) will work for a 90 gallon tank? or is it not worth the time? that's about all i'd have room for.

I don't think a 22" CC skimmer would be tall enough. CC are great because they are cheap to build and operate. The only downside is they have to be big. If you only have 22" of room to work with you better go with a becket or something along those lines. I just don't think a 22" CC skimmer will be tall enough.

electric130
06/10/2003, 06:27 AM
Originally posted by tag007
I would suggest looking for a tight smooth grained piece of bass wood, and use a fine toothed saw to get a nice clean, almost burnt cut.

i got a 4" x 4" x 8" chunk of bass wood yesterday for $4. does that sound about right?

i tried cutting it at work, and the miter saw blade was so dull that it did literally burn the wood. i only cut about an inch down into one end.

blue, i'll probably go ahead and try to build one of the KW diffusers. can you PM me, or post your experiences here? it would help. do you think i could use a radial arm saw to make one?

electric130
06/10/2003, 06:42 AM
Originally posted by AnnArborBuck
I just don't think a 22" CC skimmer will be tall enough.

that's what i was thinking. i'm looking at other options too. i might be able to sqeeze it behind the tank and stand it on the floor. luckily the tank with stand and canopy are over 6 ft tall.

what if the pump i used to fed the skimmer had an air intake before the impeller so the pump would be producing micro bubbles too. kind of like the Sea Life Systems Skimmers (http://www.sealifesystems.com/motorized.html) or the Aqua Clear Aquatics Skimmers (http://www.aquaclearaquatics.com/motorized.htm) the "75" model from both places uses the venturi intake power heads. i used to have one of the SLS 75's on my old 38 gallon. it was a great skimmer.

also, on the snailman skimmer, instead of having the pipe coming up the outside that is used to adjust the water level in the skimmer, couldn't you use a gate valve at the bottom to adjust the level? kind of like the down draft and beckett skimmers?

tag007
06/10/2003, 07:27 AM
Oh, and always cut your length across the grain, not with the grain... Should have been more clear. That size of basswood should be fine.

kevin gu3
06/10/2003, 09:30 AM
It's been a while since I had one; I just bought em one at the store and used it over and over again.

When it gets clogged take off the airline connector and nuke the basswood for a few minutes. It'll stink up your kitchen but it cleans those clogged pores right out; good as new.

Unresistible Blue
06/10/2003, 09:22 PM
Nuke 'em? who'd a thunk. I'll have to try that. By the time they stop bubbling well, mine are pretty nast/slimey. That's going to smell just grand, I'm sure.

You'll have to rip (cut with the grain) your 4"x4"x8" piece of basswodd into smaller pieces. Boxes made by pieces that came from anything bigger than a 2"x4" wouldn't fit in mine.

Electric - you can cut the blocks using a radial arm saw. Be careful, especially when you rip wood on a radial arm saw.

In short, here are some suggestions, based on my experiences:
1. Mentioned it above. Be sure the boxes you glue up will fit in the skimmer.

2. If available, use a planere and jointer to get a perfectly square chunk of basswood before you start slicing it to make the boxes. A box glued up of pieces that aren't square is is tough to work with.

3. To make sure your box is square, lap sand the ends of the box before you glue the ends on.

4. If you lap sand and do good job cutting the pieces, you can use thin slices of the basswood for the ends, rather than how KW suggests to do it. You increase the diffusing surface this way too.

5. If you turn your skimmer of for a while (few days or so), for example if you are goind to dose phyto and don't want the skimmer to pull the phyto out of the water, the boxes don't work well when you power up the pump again.

6. Plumb the skimmer to allow you the option to raise the water level higher than Snailman suggests.

7. A TetraTec Deep Water 96-2 wasn't enough to drive my skimmer.

8. A MEDO 0502 works just right. In fact, I have to bleed off some of the airflow when the boxes are new.

That's about it!

Blue

electric130
06/17/2003, 07:25 PM
HEY BLUE, (or anyone else who has made the KW diffusers)

what did you use to tap the hole in the top of the block? where did you get it? i found a nylon fitting at lowes that is 1/2" F.I.P. by 1/4" barbed nipple. is this what you all are using? if not, what fitting are you using in the top of the block?

rayjay
06/17/2003, 08:31 PM
I buy bass wood from the local hardwoods specialty store as it's cheaper than from the craft stores.
My stones are made 2"X 2"X 7" with a 7/8" diameter boar which I thread a plastic fitting into that allows me to connect to a 3/8" diameter air line.
I've actually ground the boaring bar down so the hole is a little under the 7/8" and I use a piece of black pipe with the same threads to make a tap buy hacksawing long narrow "V" cuts into the threads around the circumference. After all the cuts are made I use pliers to squeeze the open cut end pieces slightly inward. This gives me a taper for starting the thread, and relief slots for sawdust to expel while making the threads in the bass wood.
You can see the "head" these stones give my skimmers on this page:
SKIMMERS WITH DIY AIR STONES (http://www.angelfire.com/ab/rayjay/skimmer.html)
_____________________
ICQ #30079110
RAY'S REEF (http://www.angelfire.com/ab/rayjay/index.html)

Unresistible Blue
06/17/2003, 09:07 PM
electric - I just bought some nylon barb fittings from the hardware store - I glue them into drilled holes using Marine goop.

BUD
06/18/2003, 08:33 AM
Wooow, I just nuked my wooden air stone and now no bubbles are coming out.What was that recipte, I think I added too much nuke. :D

Unresistible Blue
06/24/2003, 04:01 AM
In my post above I meant to sy you'll have to crosscut - i.e., cut across the grain (NOT rip) the block into thin slices.

Sorry

Unresistible Blue
06/24/2003, 04:03 AM
I took mine out this past weekend, cleaned them with a brush to get off the nasty slime, then nuked each for a minute. They seem to be working fine again.

s a v v o
03/16/2005, 06:33 AM
I have a question for Irresistable Blue or anyone else who has experience with KW's Awesome DIY Air Diffuser.

I realise this is an old thread, but is probably better than starting a new one.

I've build a 5.'6" x 6" CC skimmer, and I'm interested in this KW diffuser.

I'm particularly keen to know how long it's likely to last before requiring cleaning, and whether or not it has a finite life when it will no longer function.

Secondly, I'd like to know how best to clean it. I read the posts about nuking it in the microwave. Delbeek and Sprung suggest a bath in bleach for limewood diffusers.

Thirdly, something which seems self evident is that all the walls of the box are cut across the grain so that the air moves through the grain. I imagine having it the other way would present an impenetrable barrier to the passage of air. Have I got it right?

Any help with these questions will be greatly appreciated by me.

Once I get going, the first step is to import basswood from your country. So far I haven't been able to find what I want in Australia.

Many thanks, and best regards,

Les Savage
Member, Marine Aquarium Society of Queensland
Brisbane
Australia

AnnArborBuck
03/16/2005, 07:09 AM
Originally posted by s a v v o
I have a question for Irresistable Blue or anyone else who has experience with KW's Awesome DIY Air Diffuser.

I realise this is an old thread, but is probably better than starting a new one.

I've build a 5.'6" x 6" CC skimmer, and I'm interested in this KW diffuser.

I'm particularly keen to know how long it's likely to last before requiring cleaning, and whether or not it has a finite life when it will no longer function.

Secondly, I'd like to know how best to clean it. I read the posts about nuking it in the microwave. Delbeek and Sprung suggest a bath in bleach for limewood diffusers.

Thirdly, something which seems self evident is that all the walls of the box are cut across the grain so that the air moves through the grain. I imagine having it the other way would present an impenetrable barrier to the passage of air. Have I got it right?

Any help with these questions will be greatly appreciated by me.

Once I get going, the first step is to import basswood from your country. So far I haven't been able to find what I want in Australia.

Many thanks, and best regards,

Les Savage
Member, Marine Aquarium Society of Queensland
Brisbane
Australia

I built one of these a few years ago and they do work great. They definetly only last so long as the pores in the wood get bigger and bigger, thus the bubbles get bigger and bigger.

To clean mine I just pulled it out and used a sharp knife to scrape the outside layer of crud off. Nuking it might cause the pores to expand due to the expansion of the water into gas inside of the wood pores, so I probably wouldn't do that. A good soaking in bleach probably wouldn't hurt, I just never did it.

You are correct about the grain. Air will only flow with the grain so if you have anyside that are not cut against the grain air will not be able to escape. The big advantage of KW's over normal air diffusers is that all four sides are porous, and thus there is less back pressure and more air flow which equals more bubbles.

As an alternative, there are some new airstones at aquatic-ecosystems that people are now using in their skimmer instead of the wood stones. These are newer stones and are getting good reviews so far.

One tip of advice if you build a KW, use a superglue gel to glue the sides, the thin stuff just doesn't seal it that well IMHO. The gel seemed to work much better for me.

Doubledown
03/16/2005, 07:20 AM
I have a CPR wet/dry that came with a built in skimmer. The skimmer is driven by a RIO 1700 venturi. It has never produced any quality skimmate and I was considering getting a bigger pump.

Could I just add an airstone for increased bubble production?

Seems like it would be more cost effective than replacing the pump with something that the skimmer might not be rated for.

Thanks
Chris

tbrennan
03/16/2005, 07:24 AM
I used one for years 4" 6ft tall I would buy 1X6 clear aspen and cut into 1X6" blocks. I then centered drilled them and used rigid airline with a drop of marine goop to hold. The big purchase for these skimmers is getting a air pump that can handle the pressure. You can add a tube inside the main chamber and place a venturi valve and pump on your skimmer for about the same price of a quality air pump.

s a v v o
03/16/2005, 08:57 AM
AnnArborBuck,

Thanks for your reply and the information you provided.

I understand now about the deterioration of the grain pores and resultant bigger bubbles. Can you hazard a guess as to how long it takes to get to this condition?

Les

tbrennan
03/16/2005, 09:05 AM
Depends on the wood and water conditions 3-6 weeks I used to change mine every month and would run 4 6" blocks at a time, the deepwater series air pumps or lufts make a good pump for the stone they are also a couple linear pumps The pump makes a big difference on performace especially on big units where you have to drive the 48" depth for the air stones

s a v v o
03/16/2005, 09:15 AM
TBRENNAN,

I'm not sure if your reply is to my question or to Doubledown, who got into the thread. I think you're talking about block diffusers. I'm talking about KW box diffusers.

Les

DrBDC
03/16/2005, 09:33 AM
Regarding whoever asked about the inlet to the air stone, at the local hobby shops they sell little mini bulkheads with air nipples on them. They work great under pressure too. On freshwater youi can use them for CO2 production which is high pressure and they are slimline enough to get 2 on a 2 liter bottle lid and are already the correct size for an airline. I think they are for fuel lines on RC planes.

Unresistible Blue
03/11/2006, 08:16 PM
Anyone found a better option yet? Anyone use those rubber membrane bubblers?