# Lighting 40B with Two Stingrays



## Doc7 (Feb 27, 2017)

Hello all,

I am going to start running a new tank. I want to dose per the Barr low tech non CO2 method which is weekly fertilization and fish waste.

To light the 40B front to back, I have two Finnex Stingray LED fixtures.










The only verified source I have found online running two of these on a 40B is a poster (Michael) on this forum runs them on a 5/3/5 siesta schedule and his tank looks awesome, although he runs a dirt substrate.

Think I should just imitate this? I hate to argue with success but don't know a lot about how the siesta affects plants (ramp up time). My "at home schedule" has no impact on tank lighting other than I want the last lights to turn off at 10 PM, we are all at work too long throughout the day for there to be a pre-work and post-work photoperiod.

Options I think of:
- 5 on, 3 off, 5 on like Michael

- 7 hours straight like I currently have them set up

- I can't find any 40 breeder tanks doing this, but what if I had something like Back Light on 3 PM to 7:30 PM, Front Light 5:30 PM to 10 pm? That would give front and back plants 4.5 hours of their brightest light but some dimmer light during the 7 hour photo period.

I will probably receive my plants on Wednesday and am hoping to pick one method by that time. I have over 140 stems coming for my initial "pack the tank at first" step.

Thanks!


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## hoppycalif (Apr 7, 2005)

I don't have enough data to be at all sure, but I do think you will do fine with the two Stingray lights. I'm guessing you will be in the low medium light range. I much prefer to run the same lighting for about 8 hours a day, no rest period at all, but that is just what I have been successful with. I know if you use a 2 bottle DIY yeast/sugar CO2 system and also dose Excel at 1 ml per 10 gallons of water every day, you will succeed very well, with minimal algae, too. I know that because that's what I do with 65 gallon tank, with a single Planted Plus light, just a taller version of that tank.


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## Doc7 (Feb 27, 2017)

Thanks to the Hoppy PAR meter I can provide some information on a 40B with two Finnex Stingray fixtures. My satellite internet is so bad at uploading photos that I will be doing this on my phone, so I won't be doing some annotations right in the photos that I would have liked to do.

First you will note that I set up the lights at 5" and 13" from the front rim which I found gave a very even PAR from front to rear of the tank for a given distance from the side walls. The clips are holding on two layers of window screen I attached the previous night to prepare for tonight's testing.



















My substrate is a bit shallow from about 2" front to 3" in the back. I estimate about 14-15" substrate to light.










With two layers of window screen on the lights, PAR (which for this meter must be multiplied by 1.08) was about 23 in the center of the tank and 18 on both ends of the tank, where less LED cones overlap.









With one layer of window screen on each fixture, PAR is now 31 at the ends of the tank, and 37 at the center.










The next step I took was to cut off screen covering 4 LEDs at each end. This allowed a more even light throughout the tank. I can always replace this later with a longer length of screen if I like. I also upgraded my clips.

















Now, my PAR is 37-40, end to end, throughout the tank. (this is the status to which I returned my tank after conclusion of testing, for my first plants which went in afterward).

Finally, I tested the numbers without any screen material. Here is what 2 Finnex Stingrays mounted on a 40B rim will get you:










55 PAR at tank ends and 60 in the center!










Here are my starter plants with my one layer of window screen except for the last 4 LEDs on each end.

Hope this helps!


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## hoppycalif (Apr 7, 2005)

Thank you for this data! A pair of StingRays can be described as a Planted Plus for shallow tanks. It is very close to lighting the 40B just like a Planted Plus lights a 65, which is a tall 40B. This is the first time I have seen where someone goes to this much effort to get uniform lighting, combining the use of a carefully located pair of lights with the use of selectively placed window screen filters.

I would have used a single Planted Plus light, hanging about 6 inches above the top of the tank. But, I'm used to thinking hanging the light to adjust the intensity. An advantage of doing that is that it also reduces the extremely high PAR near the top of the tank, which can help avoid BBA on driftwood and rocks in the aquascape. The disadvantage is that it gets hard to avoid the glare from the spillover light.


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## Doc7 (Feb 27, 2017)

With our couch/TV/reading armchair situation, these LED strips are as high as I can put them without building a canopy, so this is pretty much the optimal situation for me now. I like the uniformity because I won't need to worry about placement in tank for certain plant species for others. If it works, it works everywhere, if it doesn't work I can pull that species out and toss it without wondering if it was tank location.


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## Michael (Jul 20, 2010)

When I put the two Stingrays on my 40b, it was already established and heavily planted. None the less, I measured about 40 PAR at the substrate. I would expect the PAR to be higher in a bare tank.

Thanks for posting this.


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## Doc7 (Feb 27, 2017)

Michael said:


> When I put the two Stingrays on my 40b, it was already established and heavily planted. None the less, I measured about 40 PAR at the substrate. I would expect the PAR to be higher in a bare tank.
> 
> Thanks for posting this.


That's a great point.

I know, I know, that Hoppy will tell us that a lot of this, even after years of testing, is full of grey areas; for example, is Medium light (where i define medium light as requiring CO2 or Excel to avoid algae in amounts that are detrimental to the viewer and plants) 40 PAR or 35 PAR? Maybe even 30? This is perfectly understandable because it is dependent on the aquarist, his water conditions, etc.

I do wonder though, is the PAR that typically defines these areas (let's say 20-35 for low and 50+ for high) referring to a planted or a bare tank?

Knowing that you have a beautiful tank, rarely dosed, no CO2, it is apparent that in at least *one case* lights capable of at least 50 PAR on bare tank substrate are working well. This is probably a testament to your skills and your tank's maturity as well.

It's a good thing I don't own that PAR meter or I would probably never stop fiddling.


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## hoppycalif (Apr 7, 2005)

What "low light", "medium light", and "high light" means isn't defined in any way that has a consensus, as far as I know. When I was trying to bring some order to the discussions about light, several years ago, I asked Plantbrain, who lives near me, what the definition was, then started from what he said, and changed my definition every few months, until I was satisfied with it. At this time I believe the lowest light intensity, that ensures that several low light plants can grow, is about 25-30 PAR. And, the highest light that seems to work without any CO2 is about 35-40 PAR, so I call that 25-35 PAR low light. To me, medium light is where some CO2 is very beneficial, where all low light plants grow well, and many medium light plants do ok, and is about 40-50 PAR. Above 55 PAR is then high light, where you have to use CO2 or run into bad algae problems, and with a bit more, 60 or so, you have to try to run the highest concentration of CO2 you can if you want to grow most high light plants without serious algae problems. But, I know many people use 70-90 PAR and are able to avoid major algae problems, so for them, "high Light" is 70 and more PAR. So far, as I see it, planted tank lighting is not yet a science.

Complicating this considerably, is that I always mean the light intensity at the substrate level when I use the term PAR. But, the actual PAR in any tank varies over a wide range, from the substrate to the water level, and usually from glass to glass. Not everyone agrees with that, either.


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## Michael (Jul 20, 2010)

From my own experience, and from the results DFW APC members have from our club PAR meter, Hoppy's categories are about right. Obviously there are many contributing factors that can nudge the categories up or down for an individual tank. It was a big surprise to me that the PAR for "high light" is as low as it is. Very high PAR has become a counterproductive fetish in the hobby.


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