Co2 + O2

[pentazona]

I have a 20 litre planted tank that has

• 5 Neon Tetras
  2 Amano Shrimp

I also have a 18watt T5 Compact light over it and supply CO2 from 2 diy yeast bottles using glass ceramic diffusers.

The bubble count is 1 bubble every 2 seconds from each bottle.

The problem is that unless i use the Venturi on my Aquaball to supply O2 bubbles to the tank the fish seem to gasp at the surface .

I used only one yeast bottle before and had the same problem with the fish gasping.

If I don't have the venturi blowing bubbles into the tank i always make sure there is plenty of surface agitation but the fish still gasp.

I think blowing bubbles into the tank is driving off CO2 so is not helping my plants.

I have planted the tank with Hygrophila difformis (Water Wisteria) covering most of the substrate and some Echinodorus tenellus (Pygmy Chain Sword). At the front of the tank with some moss on a rock.

Can anyone help with the O2 issue.

 

[Underwurlde]

I think you have a CO2 problem, not an O2 problem!

What levels of CO2 have you got in there?!?!?!

Andy

 

[pentazona]

I'm not sure but when i only had one bottle feeding 1 bubble every 2 seconds the fish were still gasping at the surface.

I have read that it is near impossible to overdose CO2 with a DIY Yeast CO2 bottle.

I had good water ciculation and suface agitation but still had this problem.

 

[frozenbarb]

I'm not sure but when i only had one bottle feeding 1 bubble every 2 seconds the fish were still gasping at the surface.

I have read that it is near impossible to overdose CO2 with a DIY Yeast CO2 bottle.

I had good water ciculation and suface agitation but still had this problem.

Its possible to overdose DiY.
I Would get a drop checker or find a way to measure your co2

 

[Underwurlde]

Dude, you have a tiny, TINY 20L tank!

Go figure, stop suffocating your fish!

Bubble rate is ONLY an INDICATION of CO2 levels BASED ON AN INITIAL KNOWN LEVEL OF CO2

Measure pH and KH please & I will give you an indication of CO2 levels, but only very inaccurate...

Andy

 

[mibson]

Dude, you have a tiny, TINY 20L tank!

Go figure, stop suffocating your fish!

Bubble rate is ONLY an INDICATION of CO2 levels BASED ON AN INITIAL KNOWN LEVEL OF CO2

Measure pH and KH please & I will give you an indication of CO2 levels, but only very inaccurate...

Andy

Dont bother measuring your co2 right now!

I can say with 99% certainty that you have too much co2!!!

I have EXTENSIVE DIY co2 experience....

Your tank is very small for the co2 you descirbe.

Your fish are only surviving because you are adding lots of air to drive a bit of the co2 out. If you stop your air inputs your fish will die within 1 hour....

with a 20L tank you only need one bottle for co2 and this bottle could be a ONE liter bottle (even smaller perhaps) (1/4 - 1/8 gallon) - change the sugar and yeast in this bottle every 9-10 days

Cheers

 

[pentazona]

Always assumed that i couldn't overdose with DIY CO2. Will take one of them out the tank straight away.

If i use a 1 litre bottle should i half the amount of yeast sugar and water i am currently putting in a 2 litre bottle?

Thanks for the advice.

 

[mibson]

Always assumed that i couldn't overdose with DIY CO2. Will take one of them out the tank straight away.

If i use a 1 litre bottle should i half the amount of yeast sugar and water i am currently putting in a 2 litre bottle?

Thanks for the advice.

Yes, you CAN overdose with DIY , especially in small tanks.

Yes use half the sugar and yeast amount. I have found that using 1/2 quick rise yeast and 1/2 regular works best to keep the rate consistent for 9-10 days. Also the more o2 the yeast get BEFORE you hook the bottle up to your tank the longer the bottle will last and produce co2. I do change every 10 days but I have left it for 3 weeks before with only a small drop in co2. So if you mix your yeast sugar (and make sure you have Kh of at least 70ppm) and let it sit for 36-48 hours with a fan blowing lightly across the top of the bottle the yeast will have access to lots of o2, this will allow the yeast to incorporate sterols into their cell membranes thus making them more tolerant of the chemical changes within the yeast bottle (alcohol and PH changes).

I would remove both of them for 30 mins and add one back in a few hours

Your tetras could have permanent damage....keep an eye on them.

Cheers

 

[pentazona]

OK i have done this now and will change over the CO2 Yeast solution for tomorrow.

I will keep an eye on the tetras, hopefully i haven't done any damage as anytime i noticed them gasping i have pumped up the air input in the tank.

 

[Underwurlde]

Yes, good.

easy mistake to make really....

Andy