# CO2 difficulties



## rgrycki (Jun 13, 2005)

copied from AB 

First my tank specs:
Size: 29 gal
Lighting: 115W total lighting; 55w AHS kit+ 20W NO+ 2X20W DIY Wal-Mart 6500k CF to fill in the gaps.
Filtration: Whisper 20 HOB ~ 110GPH
CO2: DIY/2L non-collapsable juice bottle fed into 500ml bubble counter via brass bulkhead fittings then fed to powerhead venturi via valve that came with the powerhead. Both the bottle and bubble counter with fittings were tested for leaks by submersing in 5 gal bucket and blowing as hard as I could into the tubing and watching for bubbles..... leak free (after some work).
REACTOR: 12"L 2"diameter gravel siphon tube capped at both ends...The top hose connection siliconed off / the bottom one was hollowed out so water could pass through leaving only a ledge to retain my media. Media consists of ~2" of coarse algae pad cut to fit in tube. The powerhead (penguin 135 GPH) outlet enters at the top/side of the tube and is siliconed to seal and hold in place. The deflector was left on and angled down and to the side to create a vortex.
Chemistry:
pH 7.2
KH 5 degrees
gH 5 degrees
NO3 20 ppm
PO4 2 ppm
Fert Dosing and w/c as per EI using KNO3 MgSO4 and flourish. No need to dose PO4 b/c tap is 2ppm and I feed heavily. The testing was performed one day after w/c and in the evening about an hour before lights out.
Here's my problem... I only have 10 ppm CO2.

There are a number of things I can contribute it to....
When I had the CO2 going directly to a limewood diffuser placed at the bottom of the tank and in the path of the HOB current my CO2 would regularly be 20 - 30 PPM My plants weren't growing great though because I hadn't yet discovered green light tree stump remover and epsom salt. I made my DIY reactor about the same time I started the EI regimen. As far as my reactor, it doesn't seem to be doing too great. There is normally a large volume of gas swirling in the tube and steady amount of bubbles escaping out the bottom which form a fairly dense layer of foam above the powerhead. My DIY bubble counter reads about .75-1 bps (big marble sized bubbles).
My guesses: 1)The HOB is causing excessive off-gassing.
2)My reactor isn't efficient enough and needs to be adjusted somehow to perform better.
3)Since going to EI regimen CO2 absorption has been boosted and it is beyond my capacity to keep more than 10 ppm CO2 dissolved using DIY methods.
Please help me with any ideas or experiences you have. When I first came to this forum fertilizing scared me and I had no Idea how to Aquascape. After reading the vast amount of experience and information presented on this forum I believe that I have a good grip on everything and this CO2 problem is the only thing keeping me from having not just a good aquascape but a truly great one.
Pictures to come tomorrow.


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## MatPat (Mar 22, 2004)

rgrycki said:


> My guesses:
> 1)The HOB is causing excessive off-gassing.
> 2)My reactor isn't efficient enough and needs to be adjusted somehow to perform better.
> 3)Since going to EI regimen CO2 absorption has been boosted and it is beyond my capacity to keep more than 10 ppm CO2 dissolved using DIY methods.


I would say a combination of all three items is causing your low CO2 levels. I would, however, contribute it to the EI methods giving your plants more of what they need to grow causing them to use more CO2. Did you just start EI or have you been doing it for longer than a couple of weeks?

Why not just hook up another DIY bottle of CO2? A simple "T" connector and a bit more airline tubing would be all that is needed. You would then be able to change one 2L bottle out each week with a fresh DIY CO2 canister and hopefully have more CO2 production. It should also keep your levels more consistent.


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## rgrycki (Jun 13, 2005)

Thanks for the Advice Matpat. I am going to add another generator bottle today. I have been using EI for about a week and a half. Here are the pictures of my reactor and generator.


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