Plants are starving, urgent help on correct recipe??

[Skyfish]

Hi all

I am not sure where to post this, if it's wrong let me know where to Juggler/Geoffrey? Thanks

Well I have a small problem; my DIY CO2 is not generating much. I have tried it 3 times and it’s not working as anticipated.

My rig is, one 2.25L Coke bottle, then to a small coke bottle (instead of a check valve) then to the 10” gravel vac with a power head/airstone, gravel vac closed off with a course sponge.

First try I added 2 cups of sugar, 1/4 Tea spoon yeast and water to the desired level, in a 2.25 L coke bottle, leaving more then 4 inches from the top, but my mistake was I left the bottle open for a few hours before closing the cap and hokking to my rig and after 24 hours, it was still flat. So I dumped it. (BTW yeast was mixed first in luke warm water with a pinch of sugar and left for activation for about 10 mins).

Second try, same quantity sugar, but I added 1 tea spoon of yeast, this time the yeast was left out for 15 mins and it was foaming already. Then added to the bottle of sugar water as before, sealed immediately and hooked it up. Within an hour I started seeing the foam and in 2 hours the foam reached 3 inches, but NO bubble in the airstone. After 8 hours the foam was pushing through the outlet airline. And then the cap started leaking, apparently I had not tightened securely. So I dumped it again. My mistake.

Third try, brand new coke bottle, mix this time was 1.5 cups of sugar, diluted in hot water, left to cool, then 1 teaspoon of yeast ,soaked in warm water, left out for 15 mins and then everything mixed. This mix has been on for now 24 hours and the foam is only about half an inch so far. I have checked for air tightness and everything is secure this time. But still NO bubbles through the airstone. I know there is some gas as I can see it pushing at the mouth of the airstone. But not enough to push through.

From what I have read, the bubbles should be if nothing else 1 per 5 to 6 seconds?

So what is wrong with my recipe? What am I doing wrong? General rule was 2 cups sugar, half to one T-spoon yeast and water. Followed as directed.

How much foam do you see when it starts to push the bubbles thru? I am thinking MAYBE I have a minute leak somewhere? But I have checked for air tightness, it's sealed.

Any ideas? Can someone give me the best recipe for a 2.25L bottle? It’s been 4 days and my plants are hungry

I am using basic yeast.

Specs:

18W x 3 Sera Plant Care FL
24G tank, good plant load, Atman 3336 canister.
18 small fishes
Tests taken an hour ago:
GH – 8
KH – 5
PH – 7.5 (not dropped for a month)
NO2 – 0.8mg
CO2 - 5

[PeterGwee]

Arshad, your recipe for the DIY CO2 should be fine if you follow most of the general ones given on the web. The more yeast you use, the more intense the bubbling should be but the usage of sugar is higher.

Try to use a rigid bottle for the DIY CO2 solution (Coke bottles can collapse if the suction of the powerhead is too great causing all the solution to get sucked in and output into the tank.). Drop the airstone thing and feed the CO2 output into the suction of the powerhead. Install the powerhead such that the suction is facing upwards towards the water surface but well below it (this is for prevention of air-locking of powerhead when restarted in the morning.). Couple the output of the powerhead to the gravel vac tube by means of fittings...add bioballs into the gravel vac and seal off the end with the foam pad that you are using currently. Things should work better due to the low-pressure setup. No resistance in the entire line for the CO2 = less potential to leak.

Regards
Peter Gwee

[Skyfish]

Peter, thank you for your quick reply.

http://www.qsl.net/w2wdx/aquaria/diyco2.html

This is the exact system I am using except I have no check valve and only 1 coke bottle.

I have already fed the outlet of the powerhead to the input of the gravel vac, and the force is light enough to blow bubbles downwards, it's a small powerhead, about 450L/H.

My powerhead is positioned as such that the suction is from the top, 1 inch below the surface of the water and in the outlet I have put an elbow fitting and the vac is attached to it vertically just like in the diagram. The airstone is verticle.

I think I need more pressure build in the mixture. Coke bottle I can change in the next batch, first I need to get some CO2 into the tank!

Also will a strong, clear plastic jar do with a wide mouth? I have some in 2L quantity. They are rigid and airtight.

Arshad

[Skyfish]

Sorry one more thing, the coke bottle is sitting well above the tank level right now. Should I get rid of the gas separator bottle altogether? Or leave it. I like it there coz if there is ever any siphoning both ways, it will fall into this bottle and not in the tank. If there is enough pressure in the main generator, then I see no problem.

[PeterGwee]

Arshad, don't hook the CO2 tubing into the reactor chamber like what is being shown on the webpage that you have shown. Instead, hook the tubing to the suction side of the powerhead..The CO2 bubbles from the yeast/sugar mixture would get sucked into the powerhead and get smashed up into very fine bubbles which is then thrown into the reactor chamber to be further dissolved. The only problem with this method is that you have to make sure your bottle is rigid enough such that the suction of the powerhead would not cause the bottle to collapse and the yeast/sugar mixture to get into the tank through the powerhead.

(The method mention does not need any form of pressure to push the CO2 through but rather uses the suction power of the powerhead to suck the CO2 in...no pressure no issue.)

Regards
Peter Gwee

[Skyfish]

Thanks Peter, I'll give it a shot when I get home later. I'll also get a clear rigid bottle for the next batch, fruit juice bottle are available but are the milky white color/frosted, can't see inside.

Anyway, let me work on it. How high does the foam rise and we know that it's working?

Arshad

[roark]

I've recently started using diy co2 using a 1.5l coke bottle and dispensing the co2 through an airstone. recipe same as what you are using. My 2 bottles are now into the six days with pretty consistent bubbling. My bottle are on same level as my tanks.

[PeterGwee]

Foaming? It might happen if you shake the heck out of it but generally, if you leave enough gap and don't fill the bottle to the brim, things should be fine. On how to know if the DIY stuff is working, just leave the tubing in the tank for about an hour or so after mixing the new batch of yeast/sugar mixture. You should see gas bubbles coming out from the tubing. If not, check for leaks and etc. (Do not use hot water as it will kill the yeast...warm water is fine.).

Regards
Peter Gwee

[Skyfish]

Peter,

My wife just called and said that she sees moisture forming on the idside of the generator near the cap and downwards about an inch, and claims that the cap is somehow leaking. I figure I have a minute leak somewhere around the cap or from the top.

And as roark says he is doing the same thing I am doing then mine must have a leak along the line.

in my 2nd attempt I did not shake the bottle but the foam was so much that it started going into the tube and also poured out of the side of the cap. I will have to go home and do a bit of sealing again. Might have to make another batch yet again BLAH!!!

Anyway I'll update this later tonight.

[roark]

Hope this will help in your making of the diy co2. Below is what I do for mine. It works fine so I'm guessing its ok.

I melt the 2 cups of sugar with warm water and pour them into the coke bottle and fill it till it reaches the top paper label. I then add about half - 3/4 teaspoon of yeast into the bottle. I do not shake the bottle of solution and just cap/seal it up, after which i connect the tubing and "dump" the airstone into the tank. So far I see bubbles start to come out roughly about 15-30mins later. I do not see much foaming though, a little but not much.

Could it be that you're filling the bottle too full?

[Skyfish]

Hi everyone,

We have LIFT OFF!!!

Apparently I had a leak in the coke bottle cap. I made a new one and sealed it this time with epoxy, left it overnight. This morning made a new mixture, shook it a little and hooked it up. In the spare bottle I added water to make it a bubble counter. I also took out the air stone and hooked it up. In about an hour I had bubbles!!! I was getting 1 bubble every 9 seconds, but I assume with pressure it will increase.

I am so happy, thank you everyone for all the advise. Now to sit back and see the changes soon.

Want to work on my lights a bit more. Posting a new thread separately.

Thanks again.

[Skyfish]

Hi everyone

Just a quick update, the DIY CO2 is doing great, I am now getting 1 to 2 bpm!!

The water test done on the 9th before the injection was as follows:

09-6-04 Evening:

GH – 8
KH – 5
PH – 7.5 (not dropped for a month)
NO2 – 0.8mg
CO2 - 5

After 36 hours of CO2 injection the results look like this:

GH - 11
KH - 8.5
PH - 7
NO2 - 0.5
CO2 - 26MG !!!!!!! (isn't this too much????)

This an amazing change. I could be mistaken but I think I can see my plants smiling

I'll take photos tonight and upload to My Tank, them I will again in a month.

Thank you all.

Arshad