Question about DIY CO2

[IceH2O]

Why does everyone use 2 liter bottles? Wouldn't you get a longer running system using 1 gallon bottles?

Would using 2 one gallon bottles on opposite sides of the tank work on a 75 gallon planted tank?

I plan on using excel and probably will till it runs out. How long do you think a 2 liter bottle of excel will last? If 2 gallons of DIY CO2 will work I'll switch over to that. Pressurized has to wait until next yr.

Its a 75 gallon medium (right now) planted tank, 1.75 wpg dosing dry ferts 1x a week and flourish 2xs a week.

My PH is 6.8 KH is 3 and GH 2-3.... KH/GH are before dosing I'll check to see what they are now and edit the post.

edit:
GH is 11
KH is still 3

I have CaCO3 that was sent to me accidentally, could I use this in place of crushed coral or baking soda to raise the KH? I know the KH is okay for injection but I'd rather have a bit more buffer so if anything goes wrong I have a little time to react.

 

[azn_fishy55]

Well,the more volume of water you use,the longer the yeast will last.I switched from 2 2L bottles to 1 1 gallon bottle and I see a great improvement.

 

[czcz]

Recommended Excel dosing is 1mL/10gal, so a 2L bottle should last for ~260 doses.

I think most use 2L bottles because it is easy to scale for the tank sizes where DIY CO2 is most often used. You can double common mixes for 1G bottles if so inclined, of course. After staggering the bottles to increase stability, suggest you focus on reactor/diffusion efficiency to maximize mix output.

You can definitely use carbonate from CaCO3 to raise KH. Agree that a little extra buffer is nice for DIY CO2. Remember though that errors in KH levels will likely be more stressful on fish than pH drops fromCO2 injection.

 

[IceH2O]

I'm terrible with conversions so thanks.

I was reading and posted in the thread concerning the wpg conversion for CF lights.

They say my tank is med-high where I figured I was medium low.

Should I dose the excel daily, every other day, twice a week, once a week?

Guess if they're right I'm going to have to switch to compressed, but I can't do it till next yr.

 

[azn_fishy55]

In my 30 gallon high light I just dose a capful everday,but then I do run out of Excel pretty fast.

 

[Purrbox]

Actually you can use any size bottle that you need for your tanks, you just need to make sure that it is able to withstand the pressure from the CO2 mixture. I'm actually using two 1 liter bottles on both of my tanks since they are so small.

With Flourish Excel the instructions recommend daily dosing since it gasses off (not sure of the exact term). You does a larger dose right after a water change, and smaller doses there after.

Presurized CO2 would be much more ideal for your size tanks. You could get one setup and then using a manifold to allow you to use it on both tanks. This will help with the expense.

 

[malkore]

two 1gal jugs likely won't be enough. I used to run that much on a 29gal tank, with sub-par results.

There's really no alternative to a full pressurized system on a 75 gallon. Even a 55gal is a royal pain to do DIY on.