Rating CF screw ins

[ercnan]

O.K., since I'm a plant newbie, I'm going on the cheap at first with this 29g project.
Using 3 "clamp on" reflector fixtures above the tank, and using screw in cf's, what do I use to get the wpg?
The rated incand. output or the usage. i.e. 32w spiral with equivalent of 130w incand. light output.
I'm going to try DIY CO2 with PMDD, so what wpg should I shoot for.
Also, should I go with 5100k, or 6500k.
Sorry for the noob questions, but you guys are great.

[Hoppy]

You don't use the "equivalent" wattage numbers. Those just tell you what wattage incandescent bulb gives about the same light. But, the watts per gallon guidelines we use are for fluorescent bulbs with good reflectors. So, you use the actual wattage of the spiral bulbs, the 32 watt number in your example. Then, depending on what the reflector configuration is you should reduce that by as much as half because of all of the light lost due to restrike on the sides of the tube, and inside the spiral. A good light intensity for a 29 gallon tank is 2 to 2.5 watts per gallon, so you would shoot for 60 to 75 watts if you had regular straight tube bulbs, or around 80 - 100 watts of the spiral bulbs. So, three of the 32 watt bulbs should be enough for moderate light plants. But, that's just a crude idea of what you need. Four of those bulbs would probably be better. And, mounting them horizontally with reflectors that pick up the light from the side of the bulb away from the tank would be best. The color temperature is a matter of your taste. You would probably like the 6500K bulbs best.

[ercnan]

Thanks Hoppy.
That gives me a good idea of where to start.
1000bulbs.com has some 65w 6500K screw ins that I think I'll try.
Based on your info., 65w x 3 = 195w.
Half of 195 is 97.5w (my reflector setup is junk as opposed to "real" stuff, but I have it all already except the bulbs.)
97.5w divided by 29g should be around 3 wpg if I'm figuring this wpg thing correctly.
Sound close to you?
Thanks again.

[ercnan]

But as an aside, those screw ins are $20.00 for a total of $60.00 plus shipping, whereas an AHS 2x55 kit comes in at close to $100.00 plus shipping and also 2x55w 6500k lamps included.
I guess it's a no brainer that the AHS kit would be the far better option, and if I were to go that route, what would that put me at as far as wpg?
How much do you subtract for those types of bulbs? Or do you not because of the good reflectors they have. 110w puts the tank at almost 4 wpg. (3.7 actually)

[tazcrash69]

Originally Posted by ercnan

110w puts the tank at almost 4 wpg. (3.7 actually)

No subtraction on the AHS. you will be running ~3.8

BTW IMO, good stuff, easy to wire, all you need is the place to mount them.

[ercnan]

Thanks taz. I think I'll use the cobbled together stuff I have around here 'till I can get an AHS kit in here. Maybe it and the PMDD stuff will get here about the same time. Meanwhile, I'll load the thing up with plants, and hopefully have a good start.

[Hoppy]

I have the same AHS lights you are looking at, and a 29 gallonn tank. I can assure you that is plenty of light - actually more than plenty. With that light you will have to be constantly alert to spot any beginning algae problems so you can attack them immediately. Things grow fast under that light. And, CO2 is critical with that light, meaning pressurized CO2, not DIY.

[guaiac_boy]

I built a hood for my 46g bow that uses 23W spiral CF's. I have eight of the suckers which "supposedly" give about 4 wpg. I've been able to grow most things just fine, but my stem plants really only look great when they get up near the top of the tank. It was a fun experiment, and it was fairly cheap to do back when that was the primary consideration.

If you can afford it, I'd strongly recommend going with something else. I'd rate my 4wpg of spiral compacts as equal to maybe 1.5 to 2.0 wpg of good T-5's with reflectors or AH Supply's CF's. I'll be transitioning the tank to either a single 36" 96W AH supply unit or maybe a 4x39W T-5 fixture.

[ercnan]

Thanks Hoppy. What ppm CO2 do you run yours at ? Do you have it controlled by the lighting?, or running 24/7. What's the bottle size and how long does it last for you?
As a noob, would you suggest less light until I get it going?
Sort of get my feet wet first before jumping all the way in?
If I got that AHS kit, could I just run one lamp for starters, then just turn on the other one when I get more exp. ?

Questions, questions, sorry to be a pain, but I really want this to work as well as possible. I've got the 55 and 125 waiting in the wings when I get a better handle on it.

Start out small, and hopefully use the trimmings of the 29 to start the other 2.
guaiac_boy, thanks for the input. I can build whatever it takes for a hood, but like you said, cheap may not always be the cheapest option.