Extremely unscientific diffuser attempts;

[MacTech]

Okay, i'm trying my DIY soda bottle CO2 thing again, the first time i tried it for 2 weeks with a superfine "bonded glass bead" airstone underneath my Java fern to use as a diffuser

didn't work, yes the JF captured *some* bubbles, but not enough to be noticeable, it *did* however grow some nice algae on my JF

tonight, i got bored again, and tried a new diffuser idea;

cut the bottom off an empty 20 oz coke bottle, punch a slit in each of the five "lobes" at the bottom of the bottle, and cut a small cutout for the airline tubing

set the diffuser bell on top of the submerged airstone, shake up the mixture , and it emitted a large burst of bubbles, then slowed down to a steadier pace;

for the most part, the bubbles sit under the lobes and are pushed out once enough pressure builds up behind them, the bubble size is random, some big, some small, is this a workable solution, or should i just break down and get the Hagen setup

or, with a 20L with 40 watts of light, Java Moss, Wenditii, some swordish plant (it's visible near the center of the tank on my HomePage page) some Watersprite, 2 Marimo Balls and a Pygmy Chain Sword, is CO2 injection even neccecary?, i've heard some people have gotten good results just using the Flourish line and no CO2



it's the tall plant in the middle with the three flat leaves, what is it?

[glass-gardens.com]

Maybe you should just purchase the Hagen bubble counter/reactor, you can buy it for around $10.00 at several places and use your existing DIY generator.

[Rikko]

Diffusers are easy.

Couple I've made, both using an inverted gravel vac tube with an airline running in to feed in CO2:

1) A fine plastic coffee filter. Looks like a measuring cup but it's a fine mesh. Upside down the bubbles will collect but not leave, and will slowly dissolve into the water over time. The bubbles will start to rush out if the filter has more than 2-3 inches of air inside it, but with a slow and steady bubble count it hasn't happened for me.

2) Stuff a sponge in there. I cut off a piece of mattress foam and stuffed it in the top - I get absolutely NO escaping bubbles (unless I poke at it) and it was the cheapest thing I've ever done. Again, it will cause a bubble flood if the air pocket builds up too much, but I've typically got around 2" of air pocket and it's fine. When it fills up to around 4" it starts to leak (when I do a water change and the bubbles start coming faster due to lower water level).

Only problem with those is that they aren't an ultrahigh capacity diffusion solution. You basically get a set rate of diffusion and if you need more you need to deal with it another way. Contrast it to the Hagen ladders where you can run any number of bubbles through.

[bigpow]

I use a whisper internal filter, feed the bubbles directly under the pump

[Pterogho]

I run CO2 directly into a canister-filter inlet.
This keeps the CO2 in the tank-system as a whole for a considerable longer time, and gives a much higher difusion-rate, I actually never see any CO2-bubbles escaping to the surface.

I have tried it with different brands of filters though, and can from my own experience only state that Fluval can't do it. I have both generations of Fluval canister-filters and both just traps the CO2 and releases it in huge bubbles that rise immediately to the surface.
But my Eheim classics do wonder.

[MacTech]

well, the soda base diffuser didn't work, so i tried another idea...

picked up a Coralife Limewood airstone (airwood? ) and connected it to the airline tubing, the difference is amazing, it emits a fine, mist-like bubble stream, and has CO2 bubbles stuck to the stone itself, looks like it should work well





here's a QuickTime movie of the stone bubbling away
notice how the mist swirls and turns
what do you think, should this work?

[cich]

I've used the limewood (aka: basswood) diffusers before (made them myself, actually) and the only downside is that they "wear out" quickly, until it's either clogged, or the bubbles are no longer fine. Other than that, I was impressed.

I'd say that it WILL work... not as good as reactors and such, but you will at least get some CO2 from it.

--cich

[MacTech]

Originally Posted by cich

I'd say that it WILL work... not as good as reactors and such, but you will at least get some CO2 from it.

--cich

Well, isn't that the whole idea of DIY? sure, i *could* buy the Hagen Plant Gro system, but it's more fun to try to build something that does the same thing yourself...

the fact that it's cheaper as well doesn't hurt....

2L soda bottle; .99¢
airline hose; $1.25
silicone adhesive; $5.00
Limewood airstone $5.00 for 2 (so $2.50 ea.)
Yeast; .99¢
sugar; $1.25
hot water; free
total; $14.48

Hagen Plant Gro system at LFS; $30.00

[cich]

I'm not arguing!!! hehe...

--cich

[fedge]

I made my own co2 diffuser also.. I tried to make a ladder using plastic corner molding and epoxy.. that one didn't work as well as the hagen. angles are wrong and Im no engineer. (back to the drawing board on that one.. but only wasted 4 bucks on 8 feet of the stuff)..

I made one out of coke bottle .. four big holes in the sides (near the bottom.. for water circulation.. and then a bunch of marbles to weigh it down. the top neck is poked with about 1,000 pin holes made by me heating a pin with a candle and pushing it in..very small... the bottle will fill to about 3 inches down.. but after it reaches about 1/8 inch below the last row of hole it bubbles out until it is about 1/16 to 1/8 above that row...(once every 15 min i suppose).. seems to be effecient. Im running a 24oz coke bottle in the 20H .. im going to test it today to see what it has stabalized the co2 to. (BTW.. yes it took me a LOONNGGG TTTIMMMEEE to punch alll those holes in the bottle... don't do it in the cap though.. they escape WAY TO FAST then!!!)

[MacTech]

rather than start another thread on the same subject....

a while back i tried piping CO2 into my AC70, but the grindy noise as it shredded the CO2 bubbles was annoying at night, so i put the bottle away for a while....

a couple of days ago, i picked up one of those 4" Marineland blue bubble wands to use as a diffuser, seemed to work all right, i'm noticing improved growth already....

then, about 5 minutes ago, i had a brainstorm (i hate insomnia )

i have an AC mini sponge jammed on the end of the intake tube to act as a prefilter so the filter doesn't end up pureeing my juvenile Amanos, i have a bubblewand on my CO2 generator, and the AC is a great diffuser, but makes grindy noises when it sucks in CO2 bubbles....

hmm, why not put the bubblewand under the prefilter sponge, the bubbles will be slowed down by the sponge, giving them time to diffuse into the water collumn, any bubbles that make it thru the sponge undamaged will be sucked into the filter and shredded....

i should be able to use the AC70 to inject CO2 with no annoying grindy noises.... it should work....

<edit>
this morning, i checked the setup, since the filter didn't make any grinding noises last night, it either wasn't working at all, or working better than expected...

it's working better than expected, if i look at the bubblewand under the prefilter sponge, it's merrily bubbling away, the bubbles rise a couple of millimeters, then hit the sponge, for about 3 seconds they stick to the surface of the sponge, and are then slowly pulled into the sponge....

i'd imagine that since the AC sponge is somewhat "coarse" it's helping to break up the bubble of CO2 as it's pulled into the filter, either way, it looks to be working

i wonder how effective *this* system would be compared to the Hagen thingy....

[Rex Grigg]

Hagen CO2 ladder at the LFS is $12. And it works.

[MacTech]

True, Rex, but part of the fun of DIY is to get similar results on the cheap

i *could* spend $12 for the ladder, or $4 for a bubblewand that feeds CO2 into the filter, and from what i understand (correct me if i'm wrong here...), having CO2 fed into the filter where the bubble can be shredded by the impeller is more effective than the ladder diffuser, right?

so, in a sort of half-arsed, roundabout way , i've combined the "slow the bubble down to give it time to diffuse into the water collumn" idea of the ladder diffuser with the "shred the bubble with the power filter's impeller" idea....

and since i run my AC70 with 3 sponges, the CO2 will have even more time to diffuse into the water, right? (again, in theory...)

well, it definitely looks to be working, i just noticed this morning every one of my water lettuce plants has shot down a new "tap" root that wasn't there the night before....

[Rex Grigg]

The Hagen ladders are around 90-95% efficient. In fact I use one with a pressurized system on my 20 gallon tank.

[Darks!de]

I'm making a diffuser using fiberglass window screening...do you think using 2 layers rotated 45 degrees from each other would create small enough holes for the CO2 to stay under...?

P.S. And using a backup valve...am i trying to keep the tank water from backing into the CO2 bottle, or am i trying to keep the water/sugar/yeast blob from getting sucked into my tank?