uh question!? about lights

[jezx]

wen ppl say pc (power compact) what is the difference of that to a normal fluorescent fixture? cuz i got a buncha fluorescent fixtures laying around, could i juss buy the bulbs n plug it in??

[qwiksilver]

PC's have a higher output. More bang for your buck. Better par (photosynthetically active radiation) and more lumens (an easier more reliable way of measuring light). Normal output (NO) lights are allright for fish only or shallow softy tanks... some people even do ok with some LPS corals right at the top, but I would compare NO lights to an overcast day and PC's or VHO's (Very High Output)to a hazy day. Then you have your Metal Halides which are full sun, which give you the sweet glitter lines. So, it depends on the application you are using them for.
PC's and VHO's actually require different ballasts to run than a NO. PC's also require a different socket configuration. There are two pin bulbs, four pin bulbs, four pin straights, four pin squares, etc. So, they won't actually fit in where a NO bulb would even if they ran on the same ballast.

If you are looking for a way to add more light without forking out a lot of dough, you could try the screw in base PC's. They fit into a normal bulb socket that you find in your house. So, you could try to wire something up yourself if your handy, buy the 23 or 25 watt 6500K screw in PC's from HD for $8 and then, voila... a cheap way of having more intense light. Run a couple of actinics and your laughing. HTH

[kuatto]

Not to highjack the thread,but what brandname are these screwin pc's sold under at HD?

[jezx]

thanks for the info, but if i were just to go fowlr, is NO lights ok? and if i juss put softies near the top thats iite?

[StirCrazy]

Originally Posted by jezx

thanks for the info, but if i were just to go fowlr, is NO lights ok? and if i juss put softies near the top thats iite?

yes and no, there are softies that have high light requirments and softies that have low light requirments and ones in the middle. VHO, T5's, or PC's would be a lot better.

for what it is worth lummins is only accurate for measuring the exact same type of bulbs, to compare different types of bulbs then measuring the PAR is the only way to get a acurate comparason. if you haqve a meter than measure lumin the only thing it can tell you is when to change you bulb.

Steve

[qwiksilver]

Make sure if you do try to go with T5's that they are the High Output kind, cause there are NO's out there that are sold as HO, so you could get robbed in that regard. Sorry, I don't know if I missed it or not, but how deep is your tank. If it is about 12" or so then NO would be allright for softies, pretty well regardless. If it is between 12 and 20 then you'd want PC's, VHO's. Anything deeper and light won't penetrate as well.
Stircrazy, the brand is actually irrelevant. 20,000 lux (lumens per square meter) is more than 10,000 lux regardless of wether the first is Corallife and the latter Hamilton. All this says is that the first is more intense than the second. You are right though in that PAR is an even better reading. However, even better than PAR is PUR (photosynthetically usable radiation). But, to really get PUR we have to know PSR (photo. stored radiation), but I don't know of anyone that has the tools to find these out, as you have to scope out the pigments in the corals to see what is stored, subtract that from PAR and then you have your PUR. But, we shouldn't aim to provide just enough PAR to equal PSR, cause there could be factors that hinder PUR, such as water clarity, corals overgrowing corals, surface agitation, etc. So, for sake of simplicity and reliability, lumens are an appropriate means of measurement. And, the meters are readily available and fairly easy to read. Sure, I'd love to know my corals PSR and my bulbs PAR at the surface, but it's just not really feasible for me.

Kuatto, I can't really remember the bulbs name. I know it is in a white box with blue on it and it says "DAYLIGHT" on it. I used them on my fuge and they were really sweet. The only problem is they are a little yellow (too bad they are 6500K and not 10000K ). But if you add actinic to them they look good. If I remember right they aren't where the florescents are kept, but towards the front with the halogens spotlights at the store I go to. HTH

[jezx]

alright thanks for the info all. my tank is 20" but what if i were to put the softies on top of the rock, so it'll be round 3-6" below the lights is that ok?? And what kinda softies are good for juss NO lights??

[qwiksilver]

Mushrooms, zooanthids, colt coral, toadstool ( I have personally found the leather family to do better under the lower light than the brighter light, pers. obs.), Star polyps ( a great coral IMO), xenia just to name a few good ones to start with. Don't expect good growth, though, as it is LOWER light. If you want faster growth, then go with the stronger bulbs. HTH

[jezx]

thx

[StirCrazy]

Originally Posted by qwiksilver

So, for sake of simplicity and reliability, lumens are an appropriate means of measurement.

the problem with using lumens is that it is a measurment of a narrow band of visable light only and it is an average over a given area. PAR, PUR ect which is the real importance also incorperates light readings that are not in the narrow band and are also usable by the corals or plants.

the real problem that wreaks havic with lumen measurments comes into play when trying to compare lights that are composed of different spectrums. say you have two lights that are both a final output of 10000K but to get there they use different combanations of red, green and blue. sence lumen measurment is primarly of the green spectrum (if not all in the green if I remember corectly) you can have one light that is heavy in green with just enuf bule and red to balance it, or a light that is heavy in red and blue with a little green. the first bulb will measure a lot higher lumen out put than the latter but the latter will supply a higher PAR rating than the first. so this is why the lumen rating doesent work as good as we would think as I have found out from my own testing and that other have also confirmed in there testing. another problem with a lumen meter is it assumes that the light output is totaly uniform so in reality it is a hypothetical reading, where when I use my PAR meter it is a given that it is a pin point measurment that has to be in the same conditions for each measure, but because it measures the whole usable spectrum the make up of the light isn't as much as a factor as with a lumen meter.

what a lumen is good for, and I used to use it for this purpose, is to track the overall intensity drop of a specific bulb to determin its usefull life for some one who doesent want to drop the change for a PAR meter as a lumen meter can be had for 25 bucks.

I do agree we shouden't be shooting for the minimum light thats why I discourage the use of NO's except for actinic lighting. Some people have sucess with but I see more than don't than do.

as for PAR testing I don't do surface testing at all, (I might start doing some that way also) but my tests have been done through an average of 8" of water and 6" of air combined to give a realistic value not a theoretical black box value.

Steve