Planning a Co2 System for my 75g

I think I'm ready to start using Co2 in my 75 gallon planted tank. Wanted to get opinions on the setup and make sure I'm not missing anything here. I'm using the Fluval 3.0. I was going to post the settings, but I always forget you can't view them remotely.

Fzone Regulator w/ Bubble Counter and Check Valve: Amazon.com : Fzone Aquarium CO2 Regulator MinI Dual Gauge Display with Bubble Counter and Check Valve w/ 110V Solenoid Fits Standard US Tanks Easy to Adjust CO2 Level : Pet Supplies

NilocG Diffuser: Amazon.com : Aquario Neo Co2 Diffuser | NilocG Aquatics (Large) : Pet Supplies

VIVOSUN Digital PH Tester:

Aquatek Co2 Proof Tubing: Amazon.com : AQUATEK CO2-Proof Tubing 16 Feet : Aquarium Air Pump Accessories : Pet Supplies

As for the Co2 cylinder, I'm going to stop by AirGas at lunch today and see if I can get that from them.

 

Watching...

 

You'll want a Dwyer RMA-151-SSV flow meter. This will replace your bubble counter. On a tank that size, your bubble counter will be a constant stream of bubble, moving so fast you won't be able to count them.

I would also look into a reactor instead of a diffuser (if you are using a canister filter).

pH tester is good, a pH monitor / controller would be best.

 

Hi, I don't use CO2 but would like to see other comments on this

 

Indeed, a pH controller would be nice but....is it worth it if you have a solenoid?
CO2 rated tubes should not be more than $1/foot. Again, not big deal but that's not a "must have" unless you inject via atomic diffuser or other means that require high working pressure (30-50 psi).

 

You'll want a Dwyer RMA-151-SSV flow meter. This will replace your bubble counter. On a tank that size, your bubble counter will be a constant stream of bubble, moving so fast you won't be able to count them.

I would also look into a reactor instead of a diffuser (if you are using a canister filter).

pH tester is good, a pH monitor / controller would be best.

I'm using a Penn Plax Cascade 1200 canister filter. How about this?

Any alternative or off brands for the flow meter? The Dwyer is a bit pricey.

 

Indeed, a pH controller would be nice but....is it worth it if you have a solenoid?

A CO2 controller is what controls the solenoid in that scenario... So yes it's worth it. Ensuring the tank is always at optimal CO2 concentrations, not relying on a simple on/off timer.

I'm using a Penn Plax Cascade 1200 canister filter. How about this? https://www.amazon.com/NilocG-Aquatics-Atomizer-Diffuser-Aquariums/dp/B07594GKGJ/ref=sr_1_4?crid=15MORQDA6MPIR&keywords=co2+reactor&qid=1572533643&sprefix=co2+r,aps,157&sr=8-4

Any alternative or off brands for the flow meter? The Dwyer is a bit pricey.

Atomiser / diffuser inline is different than a reactor, but they should work just as well. The Dwyer is the only model other hobbyist are using/having success with that I know of. It's not mandatory, it's just a nice add-on to have a visual representation of how much CO2 you are actually injecting into the tank. You can't physically count bubbles on medium - large tanks.

 

Ok thank you

A CO2 controller is what controls the solenoid in that scenario... So yes it's worth it. Ensuring the tank is always at optimal CO2 concentrations, not relying on a simple on/off timer.





Atomiser / diffuser inline is different than a reactor, but they should work just as well. The Dwyer is the only model other hobbyist are using/having success with that I know of. It's not mandatory, it's just a nice add-on to have a visual representation of how much CO2 you are actually injecting into the tank. You can't physically count bubbles on medium - large tanks.

There is no need for "always optimal CO2 concentration" in my opinion. Let pH fluctuate. It's OK. It is natural. Fish don't care unless there is so much CO2 in the water that they cannot expel their own CO2 into the supersaturated water. For that situation, all you need is a drop checker or simply watch your fish daily.

 

There is no need for "always optimal CO2 concentration" in my opinion. Let pH fluctuate. It's OK. It is natural. Fish don't care unless there is so much CO2 in the water that they cannot expel their own CO2 into the supersaturated water. For that situation, all you need is a drop checker or simply watch your fish daily.

Optimal CO2 concentrations for plant growth are certainly needed for plants to be at their healthiest, and to keep algae at bay. This is roughly 30ppm in a planted tank with fish, but all tanks are different. At these CO2 levels, fish aren't bothered, and roughly translates to a drop in pH of 1.0.

When using a pH controller, pH fluctuates no differently than when using a simple on/off timer. When CO2 is off at night, pH rises. When CO2 is on during the day, pH drops. Using the controller allows pH to always be at a set level, ensuring plants have a consistent amount of CO2 to utilize when the lights are on. When the lights shut off, the controller shuts the CO2 off and thus the pH rises, until the controller opens the solenoid again the next day before the lights come on. The controller allows CO2 to drop the pH, and then maintains a set pH level by opening or closing the CO2 solenoid meaning a consistent amount of CO2 is in the water throughout the photo period. Inconsistent CO2 is a large contributor to algae and inconstant plant growth. Plant cells accustomed to a certain CO2 concentration perform best at those CO2 levels, when CO2 levels are fluctuating from one photo-period to the next, plant cells do not operate at their best. Plant cells require energy to adjust their cells to varying CO2 concentrations.

Without a controller, aI'm for a drop in pH of 1.0 from degassed tank water, to CO2 injected water. To do this, test tank water with no CO2 dissolved into it, then test again 1-2 hours after the CO2 has been running. Note the drop in pH. If it is less than 1.0, slowly start increasing the CO2 over a few days / weeks until the drop in pH is 1.0 by the time the lights come on for the day. Once there, you can likely add more CO2 = 1.1 drop, a 1.2 drop, 1.3 / 1.4 drop is typically where fish will start gasping at the surface. Once your optimal level has been determined, leave things be to allow plants to adjust to those CO2 levels. Monitor pH from time to time and watch fish to ensure 1) fish aren't stressed / gasping at the surface and 2) to ensure CO2 levels aren't swinging day-day during the photoperiod allowing plants to adjust to that CO2 concentration, grow their best and keep algae at bay.

Surface agitation is key here, you can have both high O2 and high CO2 concentrations in the water at the same time. Move filter outputs to create a light ripple across the tank surface, or add a surface skimmer. This will allow good gas exchange, allow more O2 into the water, and create a healthier environment for fauna and flora. Consider running an airstone at night when CO2 is off, when running larger pH drops. Drop checker should be yellow if the pH drops more than 1.0.

Example:

Tapwater pH 7.2 = Degassed tankwater pH of 7.8.

CO2 set to come on 90 minutes before lights come on.

As lights come on, pH reads 6.8, which is a 1.0 drop from 7.8. Drop checker is a light green. This is good.

1 hour after lights have been on to the end of the photoperiod, pH reads 6.7 which is a 1.1 drop from 7.8. Drop checker is a very light lime green / yellow. No fish are gasping, and plants have a healthy amount of consistent CO2 concentration to utilize.

CO2 shuts off when lights shut off, and pH slowly rises back to 7.8 over a few hours.

Repeat the next day.

 

I don't have a pH controller so maybe I don't fully understand it. When I researched it long ago, I concluded that it is an expensive toy. What I gathered is that pH controller will detect pH. If it goes up beyond a set number, it'll open up the CO2. When the pH drops below a certain number, then it'll shut off the CO2.

Then, you are saying "CO2 set to come on 90 minutes before lights come on". While I agree with this idea, I wonder how it can be achieved if the solenoid is controlled by the pH controller?

 

Then, you are saying "CO2 set to come on 90 minutes before lights come on". While I agree with this idea, I wonder how it can be achieved if the solenoid is controlled by the pH controller?

You can set the controller up using timers / smart power bars to shut off CO2 completely at night, and only control pH from 90 minutes (or whenever you choose) to the end of the photoperiod.