Jump to content

Break in period for MH lighting?


Recommended Posts


Hey guys, I've had my 250 watt MH setup for a while now and I wasn't sure if I really wanted it or not so I went with a cheap bulb (coralvue) and it bleached everything.


At first I though 250 watts was too much for a 29 gal but I've talked to several people on other forums saying that it's perfectly normal wattage and that it was more than likely the tank stressing out and bleaching from extended use right off the bat and the fact that it was a cheap bulb is why the tank never regained it's color.


So, I've been running just the two 65w PC's for the last couple of months and the tank looks great. Corline growth is fantastic and there's much more color.


I've decided to give it another try with the MH lighting because I want to start putting some coral in there. At the moment it's only a FOLR setup. So I just bought an Iwasaki 6,500K bulb.


Someone also mentioned that my tank may need to adjust to the dramatic increase in the lighting and that I should slowly "break the tank in" by only running the light short amounts of time for the first week or two.


I'm still rather new to this hobby (even though I've had my tank for over a year :D ) so I need some advice on what exactly I need to do to minimize the bleaching and what not when I put this other bulb in.


I have 3 80mm computer fans in my hood that managed to keep my tank water at a nice 79~82* during the HOT alabama summer so heat buildup is not a problem.


Any advice?

Link to comment

You answered your own question my friend. You said that people said the halide was to much @250 watts for a 29 gallon right?

So you take it off and go with 130watts of pc's. The tank regains its color and all is well. I would either RAISE the halide fixture or get a lower wattage halide setup.

I have a 175w halide on my 29gallon @14k and it will bleach out certain LIGHT LOVING corals if I dont place them on the substrate and partialy shadded.

Link to comment
matt the fiddler

tank size and brightness levels is a bad comparison


i had 250 ofer a 25 for a long time. worked great no bleaching.

tank size only matters to heat.. the deepness is the critical item.. the same bulb puts the same intensity out in a 300 gallon as a 30 gallon.. at the same place in the tank.... i have corals touching the surface under a 400 W SAKI no porblems. so that isn't your only problem



1- the SAKI is more intense than the coralvue in terms of lumen output. just more yellow...


2- was this one of the older model coralvues? the old model got a batch of bad non UV glass.. that caused bleaching- the newer ones are pretty good IMO


i would keep it 12" off, then slowly lower it to 8" off or so...

Link to comment

Yeah it's about 10 inches or so off the surface of the water. Whether ot not it was a UV shielded glass bulb, I'm not sure. I could check the serial number if there is one if that helps.


Salty, the people I talked to said it wasn't the amount of light. They said that was fine. There are guys over at reef central with way more lighting on smaller tanks (one guy in particular with 2 250's over a 20 long!) They were saying it was something else. Either the tank just was put in shock or something because I started the bulb on a normal 8 or 9 hour cycle right off the bat or it was just due to a crappy bulb.


The two pc's really don't seem like enough. It's like they can sustain life but not grow it. I'd like to keep clams and other hard corals and the two pc's probably wouldn't be enough.

Link to comment
matt the fiddler

keep the 250. slowly adapt the tank to the new lighting though.. IE bridal netting, start with the bulb 15" off, and slowly lower, etc


fast changes is what stresses stuff.. not the high light. jsut think drip acclimating your new bulb- over a few weeks

Link to comment


This topic is now archived and is closed to further replies.

  • Recommended Discussions

  • Create New...