co2 experiment - timelapse

[hadul]

Few days ago I started a little experiment related to the addition of CO2, in order to copy the schedule of CO2 addition on an automatic timer controller - but it's came out ... something else

hypothesis:


tank- 117liters 65/45/40h (cm)
substrate - Shirakura red been sands (with lowering pH properties -- but I think it lost properties due to age)
light - 7:00hour/day - 5:00 with 2 x 24W and 2 hours 4 x 24W - DIY lamp with Juwel reflectors HyFlex- ut to 30 cm above the water surface
fertilizer - vimi all in red + vimi accelerator.
minimum water agitation + surface skimmer
6.7 pH controller with hysteresis set to 0.1 (from 6.65 to 6.75)
ceramic diffusers 2.5cm - 1 buble / second
kh - 3


dslr connected to the PC as intervalometer - picture every 2 min - about 24 hours.
there is over 720 pictures that I centralized in a graph:



sorry that my english is not very well

 

[Martin in Holland]

Seems to keep it pretty stable. How high is your pH before you start injecting CO2 (light off)? Best to aim for a 1 degree drop in pH.

 

[flygja]

I think you can save some CO2 by turning off the pH controller or CO2 solenoid when the lights are off. So what do you mean by it came out as something else? Was there something else that was expected?

 

[hadul]

Seems to keep it pretty stable. How high is your pH before you start injecting CO2 (light off)? Best to aim for a 1 degree drop in pH.

this is the firs part of the experiment, I'll repeat the 24h/shootig to confirm this program on controller and after that, if the result will be similar, I'll replicate the program on a electrical outlet timer.
this was the first thought about this timelapse. I'm not sure if it will work due to multiple parameters of tank (light, waves, ferilizer, tap wather change, nr.b/s)
so the experimet will continue changing one by one of parameters to check the co2 uptake in different condition

I think you can save some CO2 by turning off the pH controller or CO2 solenoid when the lights are off. So what do you mean by it came out as something else? Was there something else that was expected?

it's no need to save co2 refilling is quite cheap
different condition co2 uptake is the new target of this experiment.

 

[ian_m]

Below is one of the "standard" charts mapping hardness pH and CO2 levels. So for your water at 3KH and pH at 6.7 you CO2 is between 14 & 22ppm, a bit lower than the recommended 30ppm for optimum plant growth and not asphyxiating the fish.

Also be very careful with such low KH water, as most pH probes won't read correctly and need about 4-7KH or higher, to read accurately. Also with such low KH you have very little buffering and can suffer from wild pH swings very easily especially if using CO2. Best to mix RO water and tap water to provided "adequate" KH or add buffering salts.

 

[flygja]

So that means your tank uptakes roughly 8ppm of CO2 per hour when the lights are on. That's including losses through degassing of course. Interestingly even with all 4 tubes on, the CO2 uptake doesn't increase. It's still roughly the same time between the pH swing.

 

[hadul]

So that means your tank uptakes roughly 8ppm of CO2 per hour when the lights are on. That's including losses through degassing of course. Interestingly even with all 4 tubes on, the CO2 uptake doesn't increase. It's still roughly the same time between the pH swing.

so whit light on the co2 decreases with 8ppm/h and whit light off the co2 decreases with 8ppm/2h (4ppm/h - only the losses through degassing )
I disagree with that CO2 uptake doesn't increase with all 4 tubes on -
you can see that the time of CO2 addition is higher (~1h14min compared to ~ 50min in other period of time ) and that means there is a higher consumption of co2

 

[flygja]

Hmmm ok... I was just looking at the time period between 18:30 and 19:20 which also ~1 hour.