Lighting calculator

[Ray]

I have to say, coming back to the hobby after a 10 year hiatus, lighting is the area that got WORSE. Before we knew roughly how many watts of T5 or T8 per litre were needed to grow different types of plants with or without CO2.

Now we have beautiful efficient lightweight LED lamps but can’t say what they are putting out without a PAR meter that most people can’t afford to own.

What should we do? Lobby the manufacturers to all publish independently tested PAR values according to a certain standard? Should all the LFSs stores rent out PAR meters like the reef shops do?

75 watts on a 329l sounds low if you want to carpet or go big on stems. I reckon crypts, ferns and mosses will go with it, especially if you add CO2. But I’m only guessing


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[EA James]

Thanks again @Wookii
Yes I'll be adding quite a few more plants, in stages. Nothing difficult or demanding though as initially i was setting up as low tech.
Best solution i suppose would be to add the EA tubes back in and keep an eye on what happens, then think about the T5 tubes if things don't work out?

 

[EA James]

@hypnogogia thanks for the link, that's another option for me. Cheers

aquarium lighting is probably the area of our hobby that I find most interesting.

It's the one i find most confusing 🤣

@Ray check out my thread on the aquascaping section and you'll see what i'm going for, nothing demanding really although i would like a nice red stem or two but on the light basis maybe not. I'm hoping Ludwigia Palustris might be alright for me

Thanks all 👍

 

[jaypeecee]

Should all the LFSs stores rent out PAR meters like the reef shops do?

Hi @Ray

I wasn't aware that reef LFSs did that? Does that include MA? Is this online reef stores only?

I'd really be interested in knowing more.

Thanks for mentioning this.

JPC

 

[Ray]

Hi @Ray
I wasn't aware that reef LFSs did that? Does that include MA? Is this online reef stores only?

I'd really be interested in knowing more.

While I was checking the price of PAR meters recently I noticed in the US Bulk Reef Supply loan them: https://www.bulkreefsupply.com/7-da...spectrum-underwater-led-par-meter-apogee.html and perhaps foolishly assumed that means this was normal.
However googling just now I'm finding lots of people saying "how do I rent a PAR meter?" and nobody offering answers so it may be I am guilty of spreading misinformation! It may be worth calling around however...

 

[jaypeecee]

While I was checking the price of PAR meters recently I noticed in the US Bulk Reef Supply loan them: https://www.bulkreefsupply.com/7-da...spectrum-underwater-led-par-meter-apogee.html and perhaps foolishly assumed that means this was normal.However googling just now I'm finding lots of people saying "how do I rent a PAR meter?" and nobody offering answers so it may be I am guilty of spreading misinformation! It may be worth calling around however...

Hi @Ray

Yes, you have confirmed what I suspected. My focus over the last few weeks has been on Cyanobacteria eradication. But, I hope to return to the small (!) matter of lighting very soon. I see you are in Switzerland. Do many Swiss hobbyists use PAR meters? With the Swiss reputation for precision engineering, they'd probably do an excellent job of making PAR sensors.

JPC

 

[Melv85]

Hi guys.

Sorry to jump in.
Was looking for a similar thing as @EA James was looking for.
And Just seen @Wookii
Has a fluval plant 3.0 over his 12 inch deep tank,
I’ve recently bought this light for a similar setup, and after years out, I haven’t got a clue really.
Can I pick your brain please mate 🙏🏼

 

[Wookii]

Hi guys.

Sorry to jump in.
Was looking for a similar thing as @EA James was looking for.
And Just seen @Wookii
Has a fluval plant 3.0 over his 12 inch deep tank,
I’ve recently bought this light for a similar setup, and after years out, I haven’t got a clue really.
Can I pick your brain please mate 🙏🏼

Fire away mate, I'm no expert on the lights, but I'll answer what I can.

 

[oreo57]

A procedure that can work fairly well if all you have is lumens:
First convert to LUX:
https://www.rapidtables.com/calc/light/lumen-to-lux-calculator.html
Then LUX to PPFD:
https://www.waveformlighting.com/horticulture/convert-lux-to-ppfd-online-calculator



30" lists 4000 Lumens.
Footprint of light panel is roughly 28" x 4".
Beam angle is 120 degrees.

Use 12"..
Area @ 12" is 21 + 28 + 21 X 21 +4 + 21" = 22.3 sq ft in free air..
Translates to 1930 LUX.
25.47 "PAR" (PPFD)

14361 LUX . At the surface of a 30x 12" (3sq ft) tank
192.54 "PAR"....
Height would be 2.3" off that "surface" (3 sq feet) ignoring the spill at the 38" l/right.
So you now have a surface "par" and a free air at 12" "par" measurement.

Now the tricky part.. How much does water/glass reflection/refraction @ 12" "train" the light into the tank?

From the above one could assume 4x increase in PAR due to the physics..
101.88 "PAR" at 12"
Listed = 111


48" Finnex planted plus 12" 107 PAR.
35.6W or 3204 Lumens (approx 90L/watt, current standard)
Possibly low.. but Finnex AFAICT doesn't list lumens.

Footprint 45x 2
So place 3" off the water line so we are estimating at 9" in the tank (3 out)
sq ft at 3" = 5.2 + 2 + 5.2 X 5.2 + 45 + 5.2 = 4.77 sq ft
7338 LUX
98.38 "PAR"


20.8 + 45 + 20.8 X 20.8 + 2 + 20.8 =

Comes to 22.5 "PAR" at 12"..
22.5 x 4 = 90
"Actual" = 107

Coincidence???

Anyone want to verify?
Just calculate the LUX based on surface area and lumens at a known PAR height.
Run it through the 2 above listed calculators and multiply by 4..

 

[Melv85]

Fire away mate, I'm no expert on the lights, but I'll answer what I can.

Hi @Wookii ,
Sorry for late reply, gone back to work, and it’s all abit manic lol.
Thanks for getting back to me.
I’m running the plant 3.0 over my tank, mines a deeper (front to back) at 18 inches. But same hight and width (24x12)

Anyway, just wondering what sort of plants your growing? And what sort of intensity for how long you run?

Thanks

 

[Wookii]

Hi @Wookii ,
Sorry for late reply, gone back to work, and it’s all abit manic lol.
Thanks for getting back to me.
I’m running the plant 3.0 over my tank, mines a deeper (front to back) at 18 inches. But same hight and width (24x12)

Anyway, just wondering what sort of plants your growing? And what sort of intensity for how long you run?

Thanks

Well, I’m not using it anymore, as I’ve switched to a Chihiros WRGB II, but I was running the Fluval Plant 3.0 at 100% for 6.5 hours a day (started at 60% when the tank was first set up) which included a 10 minute ramp up and down. Low light plants, and anything directly under the light grow fine, but I found that with the narrow spread of the light (front to back) my stems as the back of the tank struggled. It may have been less of an issue if my tank was more open with less hardscape, but even so I think a wider light gives better coverage.

 

[Melv85]

Good evening @Wookii
Thanks for getting back to me.

That’s interesting,
I was thinking the same thing, it defo doesn’t seam anywhere near as intense as my old t5’s, but others are saying I need to keep the intensity lower, and like you say with the spread the front and back look really quite dark, and my tanks 18 inches front to back, so have to have the light higher to get the spread, so loosing more of the intensity 🤔 hmmmmmm.

Did you have any carpeting plants in there?

 

[Wookii]

Good evening @Wookii
Thanks for getting back to me.

That’s interesting,
I was thinking the same thing, it defo doesn’t seam anywhere near as intense as my old t5’s, but others are saying I need to keep the intensity lower, and like you say with the spread the front and back look really quite dark, and my tanks 18 inches front to back, so have to have the light higher to get the spread, so loosing more of the intensity 🤔 hmmmmmm.

Did you have any carpeting plants in there?

I started off with Montecarlo, but it barely grew. I maybe didn’t give it long enough, but I don’t think the Fluval would have provided enough light for it - and certainly my hardscape layout didn’t lend itself to it. I switched to Marsilea Crenata and it was much better, being a slower growing lower light plant. I also preferred the way it looked and it’s been zero maintenance so far.

 

[Melv85]

I started off with Montecarlo, but it barely grew. I maybe didn’t give it long enough, but I don’t think the Fluval would have provided enough light for it - and certainly my hardscape layout didn’t lend itself to it. I switched to Marsilea Crenata and it was much better, being a slower growing lower light plant. I also preferred the way it looked and it’s been zero maintenance so far.

That’s what I’ve got in the front of mine, it’s growing, but it’s growing up, no carpeting, and looks far from healthy.
That’s a good idea, maybe I’ll go down a similar route
Abit of a shame tho, it’s not a cheap unit.

Got any pics?

 

[oreo57]

This guide may be of some help..
https://www.advancedplantedtank.com/blogs/beginners-planted-tank-101/carpeting-plants

Generally carpets are much easier w/ high CO2 injection AND the CO2 gets to the bottom. Lower light is then somewhat less important.