CO2 mesh bell...Eureka!!!! A perfect simple solution?

[fedge]

Here's how I made mine...
image shown below...

A. Cut a cylinder about 2" in height.. Diameter depends on that amount of CO2 you want to disolve into the tank (so size of tank and ammount of co2 will determin the size of the diameter).. In a 10 gallon tank and below.. about 1.5 to 2 inch is all that is needed (with about 12 or less bubbles per minute)... in a 29 gallon I used a 3" diamter pop bottle, cut up.. ) This way ALL the co2 will disolve and none will bubble past the screening material!!!

B. holes are cut for the airline, and two suction cups.

C. Cut two squares of the window mesh approximately 25-50% larger than the conatiner..

D. fit them to the cylinder.. one mesh should be a quarter turn off set from teh one below (this makes a 45 deg angle difference in the patterns and smaller holes!!) I am unsure if two are really needed but it makes smaller holes and the smaller the better. It takes a lot more pressure to sqeeze air through a small hole than a big hole (try breathing through a vaccum cleaner tube and then a straw)...


E. Finish... I attached the screens(temp) with a rubber band.. then cut off the excess screen material (be careful not to leave sharp edges for stupid fish to kill themselves on)...I plan on glueing them on next time with either hot glue or a band of plastic epoxied to the outside (like a clamp). Attach the hose into the hole..(the hole should be small enough to hole the hose securely). and then attach the suction cups...I guess any good suction cup could be used. (like the ones that hang window ornaments)... I use two so that you can level the device (important to do), and so it holds very well in teh tank. If you expose the DIY yeast to air again after it starts the co2 production you could mess up the reaction(like a fresh bottle of yeast). Hope this helps... BTW this idea is for people to use for their OWN uses.. not to make money off it. If you would like to help me develope and sell this item I am free to discuss that prospect. This is really a cheap and easy along with simple idea... it is good looking and very adaptable to any tank.

[fedge]

BTW .. this sytem has NO or not any noticable loss of Co2..!!! I watched for about an hour and never noticed a bubble of co2 or other gasses escaping (after the yeast reaction took off totally--yeast produces good co2 and has pushed out all the excess atmosphere gasses in about 12-16 hours usually..IME)

[pufferfreak]

I'm doing this for my 55 gallon now thanks!! I hope it works out, i'm going to try 3 layers of the mess caz mind has some big holes.....anyways I'm useing a plastic cup for the bell thing.....I drilled some holes in it and put some suction cups so that the thing will fit into the corner of the tank and still work ! Hope it does.....Thanks for the idea!!

[pufferfreak]

quick question, I did the same with a plastic cup, it dosent have a bottom should I cut out the bottom?? Its holding bulbes very well and I guess diffusing them good....any thoughts? Its at an angle so the bubbles sit on one side...but they stay

[zapus]

Fedge, what ppm are you getting in your 10 with this? Looks a lot easier to hide than a ladder.

[amanda huggenkiss]

Verrrry interesting... Do you think netting would work instead of mesh (with sharp edges)? I've got three fish nets -- I'm sure I could sacrifice one of them.

[pufferfreak]

I just checked my diffuser I made, and its not diffuseing any bubbles I guess, if it is it sure is slow, theres a huge bubble in there, i'm thinking about taking one of the messes off.

[fedge]

If you never see any bubbles come up from this difusor then it is working.. Sometimes gas will exchange from your tank to the air voids that is created by the CO2, just as quickly as the co2 disolves (once the system reaches equalibrium--maxium co2 around the unit)...increasing the water flow around the difusor may help the process. I have noticed that in my 29 gallon that sometimes the buble is big (like in the morning).. and in the evening it is noticably smaller(in the evening).

The reason for teh mesh has been discussed before.... its teh hole size (blowing through a straw.).. try this experiment. take a pin and punch about 20 holes (by heating the pin up over a candle) around the top of a pop bottle..cap the bottle and plunge it into some water.. you will see tons of bubbles escape.. the more you plunge it down the more you will see.. till the bottle is empty. Now, if you got tons of time to spare, make about 200 more(the more the better) and tightly packed together... try it again.. and keep doing it. Sooner or later the bottle will hold more air down below the water and at greater depths. This is the same principle with the mesh. The water has to PUSH the air through the mesh.... The greater the depth the greater the pressure (think of the ocean). So in a shallow tank like 10 or 20L's or even those 30 and 40 L's the area that is needed for the difusor is not as great... (about a 2" diameter should sufice...but a higher bubble rate will make more bubbles and need more surface area to disolve sufficiant ammounts).

In the 10 gallon I should have about 20ppm... I say should because I cannot realliably test the water right now. I have terrible green water in it( that algea eats up co2 fast!)... also I am filtering it with diatom filter today.. it will off-gas a lot of the co2. However I am at about 12bpm right now.. and that should get me a ph of about 7.2 with a kh of about 12. That is around +/-20ppm, allowing for errors. I could get more with a larger area (aroud 3" diameter) and more yeast in the mixture next time (i only use about 1/8 tsp--I don't measure sugar..just fill it to a line on the bottle--mixture lasts reasonably for about 10 days..then it falls off so I remix it..it pry could last 14 days but I don;t want co2 to drop off to greatly)

OK.. to sum up.. Netting would work.. but window screening is very cheap , and I think more durable since it is epoxy coated(if you went to a mom and pop store they pry would give you some scraps of it for nothing...BTW I bought 12 sq yards of it for about 2 dollars.. i think)

The difusion area is at the top.. where the water meets the mesh... underneath the mesh (where the bubble is) there will not be a lot of efficient disolving of co2 going on there... I would not think you would HAVE to cut the bottom out of the cup(maybe you don't want to use suction cups or can't get them.. and want to weight the device down with rocks.. then you need a bottom... I just designed mine to be small as possible. ...

Another quick suggestion... after starting a new mix...the new mix will produce co2..but has to squeeze out all the atmosphere gasses in teh line and bottle first(takes about 12 hours to do so usually from the time you start up the reaction --for me anyway)...so the next morning I take a tweezer or something else and disrupt the surface of the difussor.. then it will release all that non-disiraple air. this is NOT a nessary action since it will eventually be realeased by itself through time. But if you are really anal, like I am sometimes, and don't want to waste a micro gram of co2..then you can do this(if your mesh and device are well attached).

BTW... IM NEVER BUYING A LADDER AGAIN..

I am also waiting for someothers with bigger systems to try this out... I think the big thing is dispensing the co2 rich water around, that is why those power reactors are supperior in a big tank, when they are attached to the outlet of a filter. THe co2 rich water gets blown around the tank a lot more. I think that if you divert an out let to blow around or across this device that similar effect could be noticed. Also.. the device could be built into a longer square to fill in more area in back of the tank... or two could be used.. with a T-Valve...however, you would have to make sure that the both are at the exact SAME level in teh water.. otherwise one would get more bubble production that the other.

The best thing aout this device it is very safe... NO POSSIBLITY OF BACKPREASURE.. or the contents of your diy bottles getting sucked into the tank by a powerhead...like other systems.. and it costs really NOTHING...(less than 6 dollars for most people... and that is just for the mesh (ivestment for a lot of mesh) and the suction cups.

[Bonsai]

Fedge - Great idea & excellent illustration.

I have a possible adaptation to that .... What if you get one of those "wide-mouth" plastic 1 liter soda bottles (e.g. Mountain Dew) and cut out the top of the lid (I think that the lid is about 2 inches wide - I'll check at the store tomorrow) and use it to screw tight the window screen? Everything else remains the same.

[pufferfreak]

I just took a drinking cup and did this. I am seeing a big bubble in the top of the mess every day and night, I dont want it to get so much that it just burps and dont work. So I was thinking next time I re do my generator to take off the top mess and just have two layers. I will see how it works.

[fedge]

I got a bubble in my 3" disk of mesh that I have NEVER seen burp... sometimes the gases you see are not ALL just Co2.. sometimes gasses from the tank replace the CO2 (nitrogen, oxygen, etc, ETC)

[fedge]

I think this idea needs more people to test it out.. bigger tanks.. more co2 needs etc... Then maybe we can permenantly make it an article in the DIY. HOWEVER, before I jump the gun...I want to know how the high ammounts of CO2 will affect the window mesh material....If there is a better way, like hot glue, to attach the mesh (rubber bands will not last very long in aquarium that is sure). The pop bottle suggested would word OK.. but only for smaller ammounts of co2... or if you used more than one. If you could get a stainless steel top (threaded) with a ring that could screw down maybe that would solve a lot of problems.
NO suction cups needed, Easier to level, not as likely to rust or react.

[dewcew]

Fedge,

Great idea. I am going to try it on my 100 gallon tank. Instead of using a cut bottle, I am going to try a piece of 3" PVC or 3" ABS. I am thinknig that a slip-joint connector should be the right length.

Keep up the great work!

Dan

[pufferfreak]

btw mines on my 55 gallon

[Ironloach]

Just a thought, will this work with a foam (the one you stuff in filters) instead of a mesh?

I've noticed that the gravel-vacuum diffuser model uses foam to diffuse the CO2. Was just wondering if the same concept will work with Fedge's model.