I have 2-175&1-250 over my tank and the bulb height is about 13" off the surface of the water. I’m thinking of lowering everything to about 8". Other then the heat these lights put off is there any reason I shouldn’t lower? Then my next question is do I need to acclimate the new light height to the corals?
Hard corals are very susceptible to high par lights and it will bleach. That is why when you get hard coral you should put low on the bottom for acclimation then slowly bring it up to where you want to keep them.
If you decide to lower the light. It will be the same way and you will have to re-acclimate the corals to the strong lighting. Same thing happens when you replace new bulbs. Some corals may bleach do to the high par of the new bulb.
Ok so I did a little brain storming to figure out an easy way for me to lower my light incrimentaly. I had a hood made and my fixture sat on top of the hood,(it was open top) so what I did was got some shelving brackets and some tracks and screwed it to the inside of my hood.my light fixture is a little smaller then my hood so it fits inside of it.so I can lower my lights by 1/2" at a time. So my question is what height should the bulbs be from the surface?
Will there be a splash guard? How is the light spread? the closer you bring the light down the more concentration it will be on that location and no light spread.
Why are you bringing the light down?
I don’t think the par changes that extreme +/- a couple inches either way with halides…
i’d do whatever distance you feel comfortable with for the splash/ reaching in factors… somewhere 8’’ - 15’’ is where i’d be… are you looking for the most light possible? , or best spread? those two will give and take from each other with the height up/down…
i don’t think there is a “perfect” answer, just what works for your setup…
the par meter could help out your descision also, but i really don’t think it would matter much
:TWOCENTS
I am lowering the light because its only 175w,and I have seen others with light fixtures that sit very close to the water,(yours included when you had your mh) I’m trying to get a little better par by just lowering the light. Yes I will be needing new bulbs and I will reacclimate to the new bulbs.yes I know mh isn’t the most efficient but has been proven to work. So since this is what I have I’m just trying to adapt and over come with what I have.
gotta make the best of it right? or go rob tims led piggy bank :BB)
LOLLOL
In that case though jason, i guess you can put it as close as you feel comfy with the distance from splashing. like you said, its a small one (halide), i think its fine to go close… how’s the reflector’s spread working out for you?
I do have a piece of plexy that I removed a while back so not so worried about splash.as for spread I will need to wait till tomorrow when lights come back on to check that.
What size is your tank?
180g
Rosti had the same light fixture as me except his was 150w mh’s and he just used the leg brackets which are only like 3-4" high. I had my 250w mh’s about 8-10" high. The only bleaching I think I really had was from my ricordia’s
That’s kinda what I was comparing to. I saw the short legs those fixtures have and that was my thinking
I did not use the short legs on my fixture but I did experiment lowering the lights and raising them and have had them as close to 3-4" above water when it was that low though I needed a fan for the heat and in the summer even at 10" I needed a fan on the hot days. During winter though it was great cause my heaters only turned on at night.