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Stable CO2

So I would wouldn't be surprised if the Grow light 1000 watts Metal Halide yield more lux/PAR then natural sunlight at any given depth in our tanks and the incident angle of the metal halide is constant, but the sunlight is variable though out the day so the net light will also be greater with the metal halide also.

I envy you that you understand all this matter... But who in their right mind (No pun intended) illuminates an average indoor aquarium with an 85.000 lumen 1000 watt Metal Halide? Would be quite a task to daily top off evaporation.
 
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Regarding incident angle of the sun, remember it's also an aquarium with glass sides so that doesn't necessarily apply in exactly the same way as it would to a lake or pond etc; it could potentially get a lot more sun.

It's an old Zinc bathtub and a sort of aquaponic filter and a little aquarium hooked together. Approximately 350 litres, it's a closed system that needs an occasional water change if i like to add fresh water
That constant flow of water filtered through high plant biomass could also be an additional reason the aquarium is algae free, especially when you consider the aquarium is only a relatively small window on what must be an incredibly stable system :)
 
Regarding incident angle of the sun, remember it's also an aquarium with glass sides so that doesn't necessarily apply in exactly the same way as it would to a lake or pond etc; it could potentially get a lot more sun.


That constant flow of water filtered through high plant biomass could also be an additional reason the aquarium is algae free, especially when you consider the aquarium is only a relatively small window on what must be an incredibly stable system :)

That's also my best guess.. :) Plant mass is king! And before it has this i always see algae growth, but it vanishes as soon as the plants kick in as soon as sun intensity goes bonkers.

 
illuminates an average indoor aquarium with an 85.000 lumen 1000 watt Metal Halide?

well the running cost would be quite a bit alone. But yes I must confesses I had overlooked the amount of light the Hetal halide was outputting:oops: :thumbup:

Checked out the ADA RGB solar for comparison

upload_2020-4-5_18-38-12.png


which has an output of 3000-3500lm which converts to 21,000 Lux output at 30cm above the water (Lux (lx) measures illuminance, which is the amount of light on a surface per unit area.) at 30cm above the water

So for the Phillips HPI-T Grow light 1000 watts Metal Halide the output in lux would be height and reflexor dependant as well, with the right reflector and 30cm from water it would make the direct sunlight seem dim.

But yes direct Sunlight has x5+ the output in Lux than an ADA RGB Solar, but ADA solar directly above tank so incidence angle better so more light will penetrate, we would need to calculate the Solar Zenith Angle. At the equator its 90 degrees and for Me and Zozo its about the same all year round maxing at about 60 62 degrees Here

So without doing the maths OFC with an incidence angle of 60 degrees for the Sun and 90 degrees for the ADA RGB solar it would be a close race on a mid summers day, but for a six hour period think the ADA light would yield a higher net value
 
That's also my best guess.. :) Plant mass is king! And before it has this i always see algae growth, but it vanishes as soon as the plants kick in as soon as sun intensity goes bonkers.


Those mutton chops can't be real, they must be self-adhesive or attached using Velcro on or something o_O
 
Hi Folks,

I see no mention of PAR in the ADA Solar RGB spec. Par for the course (pun intended). No spectrum either - therefore difficult to compare with sunlight.

JPC
 
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Hi Folks,

I see no mention of PAR in the ADA Solar RGB spec. Par for the course (pun intended). No spectrum either - so difficult to compare with sunlight.

JPC

IDD :rolleyes: Typical manufacturers using units of measurement that we are not really interested in Lux and lumen when all we are interested in is PAR, but you have to use what you can to compare.
 
Well this subject has been a good one . The OP original question sort of got lost . [Hi what’s the best way to know you have stable CO2? ] The answer is do you have good plant growth? You can measure, test etc.. but it’s simpler than that.. do you have minimal algea? Are your plants growing? I’m not a scientist ,biologist or plant expert by any means. I’m just a guy who enjoys growing plants in a tank full of water no more no less. I can’t answer all the science questions but, a little common sense will go a long way.
 
Hi all,
Well this subject has been a good one . The OP original question sort of got lost . [Hi what’s the best way to know you have stable CO2? ] The answer is do you have good plant growth? You can measure, test etc.. but it’s simpler than that.. do you have minimal algea? Are your plants growing? I’m not a scientist ,biologist or plant expert by any means. I’m just a guy who enjoys growing plants in a tank full of water no more no less. I can’t answer all the science questions but, a little common sense will go a long way.
I think you have to differentiate between low tech and hi tech.

In a low tech, the plant mass is going to effectively deplete the CO2 during the photoperiod, you can get a measure of this by the variation in pH (as the CO2:O2 ratio changes). A larger plant mass will deplete that CO2 more effectively, it's back to <"Canford Park again">. During photosynthesis one molecule of O2 is produced for every molecule of CO2 incorporated. Because plants are carbon based, and they grow, we can see that they are net CO2 consumers and net oxygen producers.

There are ways of "flattening the curve" of CO2 depletion, the one I would recommend would be increasing <"the gas exchange surface area">. There is a much fuller discussion of this in <"maxing CO2 in Low Techs">, where this graph comes from.

5cxa-jpg.jpg

Partially why I like a floating plant in the tanks is that they aren't ever CO2 limited, they have <"Diana Walstad's "aerial advantage">. This is also why I think that the <"no water changes, low tech because they cause CO2 fluctuation"> isn't an argument that holds any water.

High Tech.
I'm not a CO2 user, but I think the idea behind the "stable 30ppm of CO2" during the photoperiod was so that plants aren't carbon limited, and can effectively make use of the PAR and nutrients available to them. You can still end up in a situation where CO2 is depleted (because PAR drives photosynthesis), but you can't safely go much beyond 30 ppm CO2 without asphyxiating your fish. If you don't have any livestock you could definitely add more CO2 and the plants could then utilise more PAR and nutrients.

cheers Darrel
 
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