Actinics - PC vs VHO

[EdMiller]

I would like you opinions and experiences with either PC or VHO actinic lighting.

I have been using 2 x 96w PC actinics along with my MHs for the past two years. I have not been experiencing great success with the PC bulbs. I am averaging bulb failure in under six months, sometimes in as little as three. I'm getting a bit tired of the expense of these bulbs usually around $50 - 60 each plus shipping, I've tried several brands and none seem to last any better that the other. I was checking, and I can run VHOs with the PFO electronic ballast that I have, and would like to know if these are any better than the PCs. I figure even if they don't last any longer, at least they are about half the price to replace. of course I'd have to replace the sockets, but that would be a one time cost that would make the VHOs equal to the cost of the PCs. After that they would be cheaper.

Comments please.

 

[Entropy]

IMO there really isn't much comparison. VHO actinic (mainly URI super actinic) is the king of actinic, still waiting (for years I might add) for a decent challenger.

 

[TropTrea]

the biggest culperate to PC's is heat. From the florscent family they are probably the hottest bulbs you can get. The other problem with the PC's is there design puts two tubes extremly close together with makes an effective reflector extremly difficult to design.

The actual output of a PC is about 15% greater per watt of power compared to a T8 bulb. and 20% higher than a T12. However with the PC's your only getting 55% to 65% of the light into the tank do to the reflector design. With the T8 your getting 60% to 85% of the light into the tank and with T12's 60% to 75%.

So the two big issue you need to look at are.
Cooling those PC bulbs, and having the most effecient reflector system possible.


example
bulb type light output light after reflector
PC 1,000 units 550 to 650 units
T8 870 units 522 to 740 units
T12 835 units 500 to 630 units

If I had a choice I'd go with the T8's with a well designed reflector.

Dennis

 

[Lager]

I switched from PC's to VHO's bout 6 months ago useing the URI bulbs..No Comparison ! No more Pc's for me

 

[EdMiller]

Thanks, I think the choice is clear. I've posted this same question on three forums and the overwhelming vote is VHOs. I plan to build a new hood with more cooloing fans, 4 vs 2, and will make the switch to the VHOs.

 

[Reefmaniac1]

I was never impressed with PC lamps. They came out while I was out of the hobby and when I got back in, everyone tried to sell me on PCs. I looked at tanks with them on there and remembered how my old tank looked with VHOs and there was definitely NO comparison, so I stuck with what I had.

That being said, T5s are showing some great results, PAR wise (with proper reflectors) and URI (or whatever they are called now) is getting ready to release a T5 super actinic...so T5s should finally have a great actinic lamp. That's been the hold up for me in switching over.

 

[fishy-doc]

VHO all the way!

 

[EdMiller]

If I were looking to replace the ballasts tool, I'd go with the T5s also. Unfortunately my ballasts will only run the 48 " T5 bulbs, which by my nearest calculation won't quite fit into a 36" hood. They do seem to be a very promissing light. Still, the VHOs look better than the PCs by a long shot as far as I can tell.

 

[TropTrea]

Actually T5's and PV are are extremly closely related. Basicly if you took a t5 light and bend it in half so both ends were now on the same side you would have a PC.

Where there shortfall comes is by design they are two bulbs almost touching each other wich make an effecient reflector nearly impossible to build.

Yet I can go back just 5 years when I was given a wholesale demonstration of PC's and they ahave realy come a long way since then. At that time you had one voltage 24 volts and two color selections 5.5K and actinic. They definatly were brighter then a 40Watt t12 florescent and with the space savings you could put 4 of them in the same hood that originally held 2, T12,s

I actually saw a manufacturer borouchere comparing there old 55W PC and ballast to there new 65W PC and new ballast, the output difference was 50 % greater for the slight wattage difference.

On actinics though I definatlyu note the difference in the spectrum of the PC's compared to the t-8s The PC's were peaking closer to the 400 to 410 nm range while the T-8's were closer to the 420-430 nm range. This would result in a slightly less bue output on the PC's almost going into the Blue Green range.

Dennis

<a href=showthread.php?s=&postid=7004611#post7004611 target=_blank>Originally posted</a> by Reefmaniac1
I was never impressed with PC lamps. They came out while I was out of the hobby and when I got back in, everyone tried to sell me on PCs. I looked at tanks with them on there and remembered how my old tank looked with VHOs and there was definitely NO comparison, so I stuck with what I had.

That being said, T5s are showing some great results, PAR wise (with proper reflectors) and URI (or whatever they are called now) is getting ready to release a T5 super actinic...so T5s should finally have a great actinic lamp. That's been the hold up for me in switching over.

 

[DesertBandits]

By the way if you are getting bulb failure in 6 months it isnt because PC sucks, its you. I bet those PCs are pretty close to your MH and your hood gets really hot inside. Fix your heat problems first, it doesn't matter what fluorescents you put inside there, they are still gonna be short lived if your PCs cant make it for 6 months.