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Discussion Starter · #1 ·
I have read the article on PAR but I am quite lost with it all. If I give you all my specs and dimensions and distances, can you all tell me my estimated PAR?

Standard 55 Gallon: 48"L x 20"H x 12"D

Light Fixture: Dual 48" Shop Light, with 2 T8 bulbs, at 6,500K each. 32 Watts a piece. I also have added foil tape to he shop light to act as a reflector.

Distance from Water Surface: 10"

The reason I ask, is because I am not sure if I have enough light. I want to add an extra dual shop light, but I am not sure if that will be too much or not. Please let me know, and if you need further info, just ask.
 

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Discussion Starter · #2 ·
Anybody?
 

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T8 with decent reflector(Im not sure how good foil tape is) 30 inches from the substrate is not enough light IMO. Especially if you plan on your tank being heavily planted. Not much more than 15 PAR at most in my estimation. I don't know if adding another shoplight will raise the par enough in my opinion. Because a 55 is only 12 inches front to back, and adding another light just might be spilling a lot of light outside the tank. Your may have to lower your current light
 

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Discussion Starter · #4 ·
T8 with decent reflector(Im not sure how good foil tape is) 30 inches from the substrate is not enough light IMO. Especially if you plan on your tank being heavily planted. Not much more than 15 PAR at most in my estimation. I don't know if adding another shoplight will raise the par enough in my opinion. Because a 55 is only 12 inches front to back, and adding another light just might be spilling a lot of light outside the tank. Your may have to lower your current light
Very true and I thought about that. I would just lower it to 5 or so inches. That would have to be better, right? Cause I do understand about losing a lot Of Light.
 

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I run that style of light fixture and the way you are using it is not enough light.

I keep one fixture (2 bulbs) over a much shallower tank and find it barely adequate.
Over a 2' deep tank I need 2 of them to maintain somewhat low light.

T-8 shop fixture that runs 2 bulbs of 32 watts each.
Fixtures sit on glass tops over the following tanks:
72 Bowfront 48" x 24" x varies- this is the tank with 2 fixtures.
45 gallon, several tanks: 48" and they vary from about 15" x 21" to about 16" x 16". All these tanks have one fixture.

Based on plant growth, species I can and cannot grow, and how the plants respond on the side nearest the window (much better growth) I will say that these fixtures, that height above the substrate, are all roughly low light, to the lower end of medium light.
If I lifted any of these 10" above the tank it would be too dark to keep the plants alive.
 

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Discussion Starter · #6 ·
I will be lowering it to around 5" (maybe a bit lower) and not 10". Just wanted to specify that. Also a lot of plants in my setup are low to medium light plants, like...various anubias species, amazon swords, java moss and a couple crypts.

So keep in mind that the light fixture can and will be lower than 10". Stating 10" was more of a base and truly an estimate of where the current fixture is at.
 

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Discussion Starter · #7 ·
I suppose if everyone is saying that 4 bulbs isn't enough PAR for my 55, and I have 2 at the moment, 4 can only help do I suppose I will go with the 4 bulb fixture then!
 

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You could use one - 2 bulb T8 Home Depot Diamond Plate fixture at about 5" above the tank top (or about 25" from substrate). This fixture has a much better reflector than other shop lights. I'm not sure how good the foil tape is as a reflector. I really wish my 2 bulb white painted fixture was T8 to see how an extra bulb would compare to the Diamond Plate fixture since the shop light on the chart is only 1 bulb. I don't know if you can just double the PAR for it or not. If so it would be close to the diamond plate numbers meaning it's not much better than a regular white painted fixture ... I can't believe that. Need to ask Hoppy about this. That's why I'm always hesitant to recommend this fixture since I can't see how it really compares on the chart. Here's the chart I'm talking about:




I, along with several other people on the forum use this fixture for our 75 gal tanks. I have a cold water tank so it's hard for me to really judge how good it is. Even when I first started using this fixture my tank temp was only in the high 60's .. probably never gets much above 72. Not a lot grows quick in cold water (running around 59-60 right now), except Water Sprite. I'm thinking I might have to put a heater it on just to keep plants alive. Others have said plants grow good in their tank though.
 
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