signs of bulbs needing replacement?

[jcraft]

what, if any, are the tell-tale signs of a MH bulb needing to be replaced? Short of going out, that is.

I have 7 month old Phoenix bulbs and I have a feeling they're on the out and outs. Corals still seem happy with a few exceptions- 2 frags, both of the same species, that have been in the same spot for the last 5 months and been doing great have started to "burn" on the sides facing the bulbs (i.e. one side is green, the other white)

Any other signs? I'm colorblind and I find it near impossible to detect slight changes in the intensity of the colors!

 

[Honigbiene]

try checking the intensity with a light meter?????
i`m not sure if that would work but just throwing something out there

 

[Wiskey]

I saw recentally people saying that the Phoenix bulbs are only good for about 6 months, your only other option is to get a PAR meater, that will measure the usable light your coral recieves, but get one with a waterproof probe.

Whiskey

 

[jjjimmy]

If you can see color shifting on your corals and your water parameters have not changed then it is time to change bulbs.

It is almost impossible to go by a length of time because even 2 of the same bulb will burn slightly differently and for different lengths of time.

IMHO it is always best to look at the reaction of your animals.

Jimmy

 

[mckeec]

I am running 20K XMs for about 6 months and also have seen the "burn" on a couple of my corals. As already asked, is this a sign of a bad or old bulb?

 

[jjjimmy]

What are your water parameters. I would think that high Alk would be more likely than old bulbs.

 

[mckeec]

Actually, my alk is a little low and I am raising it. The "burn" is only on the side of the coral exposed to the direct light.