2 250w HQI

[RealReef7]

In the winter I might switch from vhos to 2 250w HQI, my question is I have alot of soft/lps coral on top do you think 500w would bleach them out?

 

[fishtracks]

if you polish your vho reflecters it could be just as good as hqi

 

[RealReef7]

I really want to believe you but... I just cant imagine how it could be better? Further explanation would be great!

 

[James77]

Ya- it won't be better, halides are far more intense than VHO. You will have bleaching problems if you just jump into to full time halide lighting. Either use screens, removing one every few days to reduce intensity or simply reduce the photoperiod and gradually increase it. You can also lower all coral and slowly raise them back up if possible.

 

[SlowCobra]

HQI's actually run at about 330 watts. Also the comment about VHO being as good, that poster clearly has no idea what they are talking about. I have yet to see any of the currently offered VHO bulbs that have an external reflector being used. Do you break open the light and polish the INTERNAL reflector?

As was suggested, get screen material from the hardware store. Put about 5 or 6 layers on top of the tank. Once a week remove a layer. Hopefully this will eliminate any issues with the lighting change.

 

[cobbobby]

Only if you run the HQI ballasts right SC, like the M80. If you run an eballast it will run in the 250-280w range. And yes, in no way imo are a vho going to come close as a hqi mh, especially 250w.

 

[SlowCobra]

Correct on it being only the HQI ballasts.

 

[RealReef7]

Thanks for your help guys when u mean a screen do you guys think egg crates can get the job done? How long will I have to do this?

 

[James77]

Any kind of window screen- use about a half dozen layers and slowly remove them over the course of 1-2 weeks.

 

[dstacy]

i have two 250w HQI for my 55 gallon tank and haven't experienced blanching yet...did start it out with a light diffuser though

 

[RealReef7]

Alright thanks! Just curious will the 2 250w HQI'S heat up the water pretty good?

 

[James77]

They can if not vented right. If you put them in a sealed canopy with no fans, it will warm the water quick. Blow some air on them and across the water and you will barely notice them. VHO also heat the water. I don't know how many watts VHO you run- but if you had 500 watts VHO, 500 watts of HQI halides would heat the water only slightly more.

 

[sedor]

<a href=showthread.php?s=&postid=15487579#post15487579 target=_blank>Originally posted</a> by RealReef7
Alright thanks! Just curious will the 2 250w HQI'S heat up the water pretty good?

I have 2 250W Halides on an open top. I have a fan under my canopy blowing on the sump, but nothing blow over the surface right now. My temp usually goes from around 79 to peaking at about 82.8. So yes they do heat the water some but I bet if I had fans blowing across the water it would be fine. I just don't think the fluctuation is enough to worry to much about it. Kinda simulates the water warming due to the sun in the middle of the day IMO.

 

[RealReef7]

I have 440w's of vho. So it will be a good idea to add 2 fans inside the canopy facing each other? Btw the canopy is open in the back.