Probably a stupid question but when we measure to the bottom of the tank for the purposes of this chart are we measuring to the glass bottom or to the substrate?
Lighting a Planted Tank
- Thread starter WyldFya
- Start date
To the substrate. you need to know how much light will be reaching the base of the plants. that's why i still dont know how much lighting i have 
i have a hanging fixture and i dont have substrate yet!
i have a hanging fixture and i dont have substrate yet!
How do we find out micromols of PAR for our bulbs? You say T5h0 are 65 but how do you figure that out? Im confused by this chart and dont know how to read it. I guess oyu need to know the micromols of PAR of your bulb right? Then you check the depth?
nope, it's all in the chartPyramid_Party;4300505;4300505 said:
the vertical data is the micromols of PAR, the horizontal data on the bottom is the height (in inches) the fixture is from the substrate. measure how high your fixture will be from the bottom and check the PAR reading for that type of bulb
CFL bulbs are a totally different animal. That is because is they do not produce uniform light due to their weird shapes. A straight flourescent light tube because it's uniform light. I'll just refer to this great post here:Pyramid_Party;4311655;4311655 said:
Follow-Up: Household CF Bulbs, Growing HC, and Non-CO2...
I wanted to follow up to this thread to share some more ideas on lighting with household CF bulbs. AirSong originally had posted asking how much light she should use to light her 2.5gal non-CO2 tank... She was interested in growing HC or other carpeting plants. To her, I answered that she would probably need more than 15 watts. I didn't want to leave it at that however. I set out to investigate and find the right answer. As such, I duplicated her setup: tank size, fixture type, water depth, distance of light from the water, etc... and then took some measurements.
The answer is that you can use anything from 14 watts to 27 watts, and beyond. It all depends on how you set it up...
I personally believe that many hobbyists underestimate the need to accurately quantify their light - especially when they are plagued by unexplained algae or dying plants. The growth in non-CO2 tanks is quite slow and getting feedback takes too long. It's good to know from the start that your lighting is in a good range, so you can eliminate it as a variable if your tank is "less than desirable".
As I discovered, these CF bulbs (14-23 watts) seem fairly tame, but how you use them can mean the difference of not having enough light, and having way too much. And believe it or not, that difference can manifest itself just by moving the light up or down a few inches.
I created a several slides to show what I'm talking about. I hope this will help illustrate how things like reflector type and distance make a big difference, and can't be overlooked - it is also the reason one person's success with a particular bulb may not be your success.
(Hopefully, you've turned off that pesky "image resize" in your user preferences - if not, make sure to unscale for readability. )
Diagram1 - Household CF Bulbs
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Diagram2 - Measuring Household CF Bulbs
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Diagram3 - 19W, 5500K Example
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Diagram4 - Does Color Temperature Matter?
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Diagram5 - 23 Watt Extremes
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Diagram6 - Reflector & Orientation
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Diagram7 - 14 Watt Example
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Cheers!
Since lighting is measured by type of lighting/lamp and the bulbs, what would be the difference with using higher watts?
Say, using a T5HO 24 watt vs a 54 watt T5HO? Some people run higher watts but since it isn't measured by watts anymore, what benefits or problems would there be with higher watts?
Say I got a T5HO over a 29 gallon, Im using only one bulb and according to the chart it brings me to medium lighting. If I were to add another bulb or higher watts what will this do?
Say, using a T5HO 24 watt vs a 54 watt T5HO? Some people run higher watts but since it isn't measured by watts anymore, what benefits or problems would there be with higher watts?
Say I got a T5HO over a 29 gallon, Im using only one bulb and according to the chart it brings me to medium lighting. If I were to add another bulb or higher watts what will this do?
the difference in watts is the length of the bulb. 24w is 2ft and 54w is 4ft. you can add a 54w if you want, if you dont mind it looking like a ridiculous teeter-totter on your tankPyramid_Party;4323965;4323965 said:
Hi, Im a little confused here. The distance between the light source and the top of the substrate is 24 inches. I have two 54 watt T5HO's (4ft) for my 5 feet tank. Obviously my lighting fixture is a few inches short for my 5 ft tank from each end but the 54 watt T5s were the closest fixture in size that I could come up with. So under what category does mine fall into? Low, medium, or high? I hope I didnt confuse you either.
TIA
TIA
based on the chart, one T5HO bulb at 24" gives you approx 42 micromols of PAR. two bulbs gives you 84, so that puts you at the bottom of the high-light category. but you gotta keep in mind that your light intensity will not be the same at the edges of tank since you dont have a fixture that spans the whole tanksepehr;4326181;4326181 said:
it all depends on the length of tank, height of the fixture, etc. in general, two rows of T5HO bulbs will give you high lighting on ANY tank. the biggest myth out there is that freshwater plants need a ton of light, and this couldnt be further from the truth. and the WPG rule is largely to blame for this. people try to use fixtures meant for saltwater tanks over freshwater planted tanks. this is a big mistake. a freshwater plant simply does not need the lighting corals do.Pyramid_Party;4327548;4327548 said:
Tom Barr has even tested Takashi Amano's famous planted tanks with a PAR meter, most of them have readings even lower than what is considered "high" light according to this chart. the hard part is getting people to understand they dont need a ton of light. the WPG rule is so embedded in their brains they refuse to believe anything else. but adding lots of light will lead to a tank that is nearly impossible to manage. it will be difficult to keep co2 up to par with tons of light. i'm gonna post a new thread in a few minutes about this high light myth...
