# cfl lighting correct?



## mattinmd (Aug 16, 2014)

How much the fixture focuses vs spreads light is less about the diameter and more about the shape of the reflector surface...


If the 10.5" they used is something like this, with a nice smooth, fairly parabolic curve:
http://www.walmart.com/ip/Bayco-10.5-Brooder-Clamp-Light/14003468

It will focus the light into a much smaller spot than a fixture that has ridges in it like this one:
http://www.walmart.com/ip/Bayco-8.5-Clamp-Light/14003467

Those little ridges cause light scattering, which in some contexts is good (ie: do you want a spotlight or a floodlight?)

Also, make sure you read your PAR after the light has had several minutes to warm up, as they do increase in brightness a bit (some older models quite a lot) over the first 10 minutes or so.


----------



## Bryanmc1988 (Apr 3, 2012)

I have the dome fixture with the ridges in them... And the light has been running for over 10hr before I tested with the par meter. 

So what am I doing wrong here?


----------



## mattinmd (Aug 16, 2014)

Well, the ridges will reduce your PAR. As I already said, they scatter light... Scattering reduces PAR, and increases the area covered. If you want more area that's good.. if you want more PAR in a small space, that's bad.

The results in that graph suggests that the reflector in that domed fixture is very good, and very focused...

See how the 15w CFL is beating out a 26w reflective floodlight by a factor of more than 2 at 20"? That means that dome is focusing the light a lot better than a standard reflector floodlight does, and is hitting about 1/4 the surface area at 20" distance.


----------



## Bryanmc1988 (Apr 3, 2012)

So instead of my buying 9 clamp light reflector to get the whole 125gallon tank at 50par from left to right...

What do u think about using only 3 light fixture like this?









When I mean 3 I mean taking the fixture off the pole and hanging each one up...

They use helagon bulbs and there is a 500watt and a 1000watt fixture, not sure how these work or heat but can I put in a smaller watt helagon bulb in a fixture rated at these watt on the box?

Also what do u think about this fixture? It's from Walmart. For about $33 for the 2 per pole or $11 per fixture each


----------



## Dead2fall (Jun 4, 2014)

Bryanmc1988 said:


> So instead of my buying 9 clamp light reflector to get the whole 125gallon tank at 50par from left to right...
> 
> What do u think about using only 3 light fixture like this?
> 
> ...


Those halogen bulbs get HOT. I wouldn't use them. Plus I don't think they're the correct spectrum.


----------



## mattinmd (Aug 16, 2014)

+1 on the heat... those things generate more heat energy than light energy. They are enough heat to be a fire hazard if you do dumb things like toss a shirt on them.

A 500w halogen is around 8000-9000 lumens, that's about the same amount of lumens as a pair of 54w T5HO's (4000-5000 lumens each)... That means that most of that 500w is pure heat.

As for the spectrum, halogens are 3000k, slightly "cooler" than a 2700k incandecent with similar spectral profile otherwise... probably not "optimal", but plants will grow in almost any spectrum. Some spectra are less efficiently used, but the idea you "must" have 6500k is a bunch of horsehockey in my book.


----------



## Bryanmc1988 (Apr 3, 2012)

So what's the best choice to go with in terms of low budget and less fixture that is needed...

Say 3 dome work light fixture with a ??? Watt bulb for each fixture on the 3 open holes at the top of the tank?

Looking for low cost but enough to get around 50-55 par at 24"-27" from the substrate to the light?


----------



## Hoppy (Dec 24, 2005)

I don't think you can get that much light from a CFL bulb in a typical dome reflector at that distance from the light. There are several T5HO light fixtures that will probably work.


----------



## mattinmd (Aug 16, 2014)

Hoppy said:


> I don't think you can get that much light from a CFL bulb in a typical dome reflector at that distance from the light. There are several T5HO light fixtures that will probably work.


Any chance you can update your article to reflect that fact? The existing PAR graph is potentially misleading....


----------



## Bryanmc1988 (Apr 3, 2012)

dont need too as the graph in hoppys page is correct and here is what i have done...


















home depot 8.5" dome reflector with 6500k 23w screw in cfl (Philips brand- not the crappy after market brand) where you see the red mark lines are where the lights are hitting at 60 pars

its sitting at 24" from the substrate. and shine's 60 par all over the tank, front to back and from left to right...


now if i just used one fixture on each hole opening at the top, i would still get the 60 par in the middle but as i move the par meter to the corners, it drops down to around 29-30 par... the front and back from the fixture still gives me 60 pars but the corners will drop which is weird but for this reason, i had to add another fixture about 3" apart from one another to get a full 60 par all the way around a 125 gallon tank


P.S. dont buy the eco start cfl bulbs.... although it looks and labels the same on the box, the light is nothing close... its about half of what you get from the philips brand... (30 par on the eco start 23w cfl vs 60 par from the philips 23w cfl). The price is not much different to in my area, not sure about yours, $10.97 for eco start cfl or $12.97 for the philips brand... for an extra $2 i rather get a reliable cfl bulb from a known brand for its works... and like most people say, you get what you payed for....



total cost for me to get this lighting is about $90, a lot less then the $500+ for a 6' fixture t5ho...


----------



## burr740 (Feb 19, 2014)

These are 23w 5000K in 8.5" domes over a 20H, approximately 18" from sub


----------



## jeffkrol (Jun 5, 2013)

bryanmc1988 said:


> dont need too as the graph in hoppys page is correct and here is what i have done...
> Total cost for me to get this lighting is about $90, a lot less then the $500+ for a 6' fixture t5ho...


*



used se quad 72" 6500k led aquarium light freshwater plant discus 112x 3w #115

Click to expand...

*$200.............


----------



## mattinmd (Aug 16, 2014)

Bryanmc1988 said:


> P.S. dont buy the eco start cfl bulbs.... although it looks and labels the same on the box, the light is nothing close... its about half of what you get from the philips brand... (30 par on the eco start 23w cfl vs 60 par from the philips 23w cfl).


Ok, so it sounds like the real issue was the eco start CFL bulbs having low output... Glad it worked out.

As for the spread, the Hoppy graphs generally only report the peak PAR values, not a tank-wide average. In the case of a t-whatever that "hot spot" is going to be a strip right under the bulb. In the case of a circular reflector, it is going to be a disc right under the fixture.

What you did by adding more lamps to get an even light distribution is the right way to go... tube fixtures often need multiple to get even front-to-back, so this isn't a unique issue.


----------



## Bryanmc1988 (Apr 3, 2012)

What do u guys think about building a good diy led fixture? How many work one need for a 125 gallon aquarium? And what's the average cost of a diy led build? Cheap star led?

Bump:


jeffkrol said:


> We quad 72" 6500k led aquarium light fixture


What's the light spread on this led from 24" and 27" high from the substrate? Will it cover the whole 125 gallon tank and what would the par give?

Bump:


burr740 said:


> These are 23w 5000K in 8.5" domes over a 20H, approximately 18" from sub


Isn't 100+ par way to much and will lead to massive algea problem even with co2 injections?


----------



## jeffkrol (Jun 5, 2013)

Bryanmc1988 said:


> What do u guys think about building a good diy led fixture? How many work one need for a 125 gallon aquarium? And what's the average cost of a diy led build? Cheap star led?


Great idea, but don't really expect to save much since normally you will overdesign (dimming ect) 100 cheap 3w 6500k emitters only runs about $30


Bryanmc1988 said:


> What's the light spread on this led from 24" and 27" high from the substrate? Will it cover the whole 125 gallon tank and what would the par give?


PAR like this:









Lensed at 90 degrees, removable to increase spread to 120 degrees


Bryanmc1988 said:


> Isn't 100+ par way to much and will lead to massive algae problem even with co2 injections?


Depends...
On the plus side of the beamswork quad 3W fixture is 2 power supplies so you can easily run 1/2........


----------



## Bryanmc1988 (Apr 3, 2012)

When u say depends what does it depend on? I was referring to the tank he had setup up with 100+ par, isn't it to much for his tank or I mean for any tank that can get 100+ par at the substrate?


----------



## jeffkrol (Jun 5, 2013)

Bryanmc1988 said:


> When u say depends what does it depend on? I was referring to the tank he had setup up with 100+ par, isn't it to much for his tank or I mean for any tank that can get 100+ par at the substrate?


http://www.liveaquaria.com/PIC/article.cfm?aid=4


> *Light*
> Light is one of the more perplexing components to algae control, as algae will thrive under low OR high intensities. Without aquatic plants, low light conditions will favor the growth of algae, since there is no competition for the light or other nutrients.


I've seen nothing to counter the above opinion...
Is it harder under high PAR?.....It depends. Low nutrients in the water column, algae scavengers, high CO2, high plant density and algae will be low..

erring on the high side and going down is usually cheaper than the other way around..

my main point to start w/ was a comparative par/par cost of LED vs DIY Cf's..


----------



## mattinmd (Aug 16, 2014)

Very High light is doable, sometimes. 

Basically the higher you go in light, the more chance there is for some small mistake to spiral out of control. 100 PAR is, in my mind, more of a "warning, don't go here unless you know what you're doing" kind of level. 

If you have the discipline to keep at it, the experience to recognize problems early, are willing to keep up on the maintenance, and choose your plants carefully, super-high par is doable. There are a few here who do. They are not beginners.


----------



## jeffkrol (Jun 5, 2013)

Bryanmc1988 said:


> When u say depends what does it depend on? I was referring to the tank he had setup up with 100+ par, isn't it to much for his tank or I mean for any tank that can get 100+ par at the substrate?


Worth reading..
http://www.barrreport.com/forum/barr-report/lighting/7748-the-high-light-requirement-myth

I freely admit to probably "selling" more light than less..but as I said.. it is really much easier to deal with. 
You are always "source" limited..


----------



## jart (Jan 17, 2003)

mattinmd said:


> If you have the discipline to keep at it, the experience to recognize problems early, are willing to keep up on the maintenance, and choose your plants carefully, super-high par is doable. There are a few here who do. They are not beginners.



"...choose your plants carefully..."? Care to elaborate? Are you suggesting that fast growing plants would be best suited for this application?


----------



## mattinmd (Aug 16, 2014)

I'm not one with the experience to answer...

I just know that most PAR limits are somewhat pliable if you stock right... 

I'd suggest reading some of Xiaozhuang's posts in this thread. A lot of it is about going over the PAR limits for low-tech, but the general thoughts and ideas are the same.

http://www.plantedtank.net/forums/showthread.php?t=743785&highlight=


----------



## burr740 (Feb 19, 2014)

Bryanmc1988 said:


> Isn't 100+ par way to much and will lead to massive algea problem even with co2 injections?


Others have explained it pretty well. Here is my 75, four T5HOs, 8 hrs/day











There is no magical secret. 

Plenty of ferts (EI)
Plenty of CO2
Good flow/oxygenation
Weekly 50% water changes. 
General good tank husbandry (clean filters, substrate, etc)


At the first sign of trouble, double or even triple up on water changes until you figure out what the problem is. That will cover a multitude of sins. Usually it is CO2 related.


----------



## jart (Jan 17, 2003)

Thanks for the link *mattinmd*. Interesting read.

*burr740*... I know there is no gold standard for "heavily planted", but I find it amazing that you are achieving that color and plant health with, what some might call, a "less-than heavily planted tank". I mean, your substrate is covered, for the most part, but your stems are mostly trimmed back. Do you keep them trimmed back to make sure your CO2 distribution is ideal?


----------



## burr740 (Feb 19, 2014)

jart said:


> Thanks for the link *mattinmd*. Interesting read.
> 
> *burr740*... I know there is no gold standard for "heavily planted", but I find it amazing that you are achieving that color and plant health with, what some might call, a "less-than heavily planted tank". I mean, your substrate is covered, for the most part, but your stems are mostly trimmed back. Do you keep them trimmed back to make sure your CO2 distribution is ideal?


Hi jart, thanks.

I'd just trimmed the stems a couple days before those latest pics. I do that about every two weeks. They'll hit the surface in about three if I let them. I like to keep them growing in the middle range of the tank for the most part, rather than near the top. They grow slower and are easier to prune and shape....for me at least. Pruning is something Im trying to learn better atm.


----------



## Lazlo (May 5, 2015)

Wow that's a big difference in par. What brand bulbs are you using Barr? I'm setting up 8.5" domes for my 29g currently have 6 13w 6500k Phillips mounted horizontal in the plastic t8 hood. Feel it's way too little light, though once the plants get to top of the tank they do well. Got my diy co2 rolling good and picked up dry ferts. Ready for more light but aiming for 40-50 par. I would like the lights to be about 2" above the glass top around 20" from substrate using 3 domes for spread. Home Depot doesn't have the Phillips 23w in 6500 just 13w lowes has sylvania micro mini in 23w. Seems 13 is not enough and 23 is too much unless it's way above the tank. That's doable but don't really like all the light in the room just in the tank.


----------

