65W PC into 55W setup

[uwscotch]

I think the title says it all. Are there any concerns using 65W power compact bulbs with a 55W PFO Ballast. The 65W are more readily available. Am I just not taking full advantage of the lighting capabilities, or is there a real concern with safety or the quality of the light emitted. On a side not, how high do you recommend MH be placed from the surface of the water? In this particular case, a 175W MH over a 29G tank. How tall of hood? I intend on cooling it with a 4" fan. Any general recommendations would be appreciated. I'm sure there is a recommended safe distance and then there is the realistic distance that people use in their tanks. This should maybe be a poll of how close is your MH and how tall is your hood?

 

[Zephrant]

I've not tried it, but in general a 55watt ballast will not be happy trying to drive a 65w bulb. If it works at all, it will be running too hot, and no doubt fail prematurely.

The other possibility is that the ballast can't provide enough current, and would not drive the 65W bulb at full capacity.

Either way, I would not advise it.

Zeph

 

[mfinn]

I asked the people at www.hellolights.com pretty much the same question and they said there is no difference in the bulbs.
I use 65watt bulbs in 55watt ballasts and the other way around and I haven't seen any problems.

 

[uwscotch]

Thanks for the thoughts. That was a good idea asking a question at Hellolights. They have contact numbers and e-mail addresses but I never think to get in touch with the manufacturers since they are the experts. Any thoughts on the MH distance/hood height? Thanks all

 

[mfinn]

I have 2x175watt and a single 250watt, 9" above the water on a soft coral tank.

 

[dwall174]

I use 65watt bulbs in 55watt ballasts and the other way around and I haven't seen any problems.

I agree with "Finn" it don't matter! I have a JBJ 260 watt fixture that I had to replace a ballast in! They claim it's a 4 x 65 watt fixture, However when I replaced the ballast it clearly looked like a 55-watt x 2 ballast? I think it's just a marketing thing! In fact I replaced my JBJ 65-watt lights with A.H.Supply 55-watt lights & I could see no difference other than I like their 03 actinics a lot better than the JBJ actinics! & their prices are about 1/3 less :razz:

 

[gobie]

It Does Make A Difference. Is It A Tar Balast Or Electronic Balast? If Tar You Stand Achance Of The Tar Melting Out Out Of Balast If It Runs Too Hot. This Will Blow Your Balast And Your Bulbs Will Blacken Pematurely Changing The Spectrum Color Shift To Yellow Or Even Red Causing Algae Bloom. Here Is Somthing To Look At If Multi Bulbs You Are Increasing The Wattage 10% Output X However Many Bulbs If Your Balast Already Runs Hot It Will Increase The Heat Of Your Balast Causing Meltout Of Tar. Get A Hold Of Mfg Before You Do This. Trust Me It Will Save You Money.

 

[mfinn]

I did talk to the manufacture
When I talked to hellolights, they told me that when Custom SeaLife started to market their products they wanted an edge over the 55watt pc bulb market, so they advertised the bulb they had as 65watts even though they were really 55watt.
I currenty have a aro ballast (tar) 2x55 watt and have 2-65 watt bulbs. Everythings cool.

 

[Elmo18]

I just want to add to this as I just saw this old post...

that it is the ballast that drives the bulb. If you have a 55 watt pc ballast and running 65 watt pc bulb, the bulb will burn at the 55w rate.

If you have a 65w ballast and have a 55 watt bulb, then you will overdrive the bulb by a little, but there is no harm in that. The bulb should still last as long, or maybe a little shorter.

- Elmo