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JMeesh
07/14/2007, 10:19 AM
hi guys. i recently upgraded from a 72w pc fixture to a 175w single ended metal halide setup. this is all over my 20 gallon tank.

in the 72w fixture i had 1 10k bulb and 1 blue bulb, both running 36w of course. its the coralife one. in the 175w i have an old 12k reeflux (i think) bulb donated from a great guy locally. i have a spider reflector, and a magnetic g.e. ballast. the bulb is about 8 inches off the water.

my question, finally :) is this - why does my tank look dimmer? it looks not as bright as when the pcs were over it. im not talking about under something as i know pcs reflect more. i mean smack dab on top of the center rock. it is much more purple, for sure. i understand the whole kelvin rating system, no problem. it just looks dimmer, weird as i now have more than 100 more watts and its halide not pc.

should i be able to see clues about the par my tank is receiving? my frogspawn changes its look some, it seems to stretch a bit more, but gets nice bulbs on the ends of it where as before it was just a tube.

of course, this is only after 2 partial days so my tank is nowhere near acclimated to it. i was just wondering, and as i mentioned in a different thread, i have no patience!!!! any ideas?

meesh

lcashman
07/14/2007, 11:00 AM
be patient....with the higher K bulbs the tank may look dimmer, but actually the corals are recieving more intense light.
Also be careful on how long the lights are on....especially when changing from pc to mh. You may end up bleaching/burning corals with the different intensity.

JMeesh
07/14/2007, 11:17 AM
yea ive got my eye on the tank for sure. i ran 2 days with only about 3 hrs of halide at the end of the day. i dont want to injure anything.

do you know of any visual indicators that would clue me in to the amount of par? i have kenya, xenia, frogspawn, zoos, ricordia. i know the best thing would be a meter, but alas i have none.

thx cashman

meesh

lcashman
07/14/2007, 11:23 AM
keep an eye on the frogspawn...like you stated in your first post. Also, if the corals do not like the intensity of the light, they will move or stay closed until adjusted to the new light source.
Most of the corals in your tank will adjust to the new light quickly. As you increase the length of time, you'll see more differences in the corals.
Once again....be patient and everything will adjust to the new light.