175 watt mh light
- Thread starter pagano24
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stanlalee
Active Member
how big a tank doesn't matter. one lamp can support a 2x2 foot area with a "normal" reflector and up to 3x3' area with a more developed wide coverage reflector (lumenmax elite for example). 175w is good for a tank depth of about 20" give or take a few inches. I had 175w aqualine 13k over a 19" tank and acro's grew very fast and could keep anything and I just had sunlight supply batwings for reflectors
pagano24
Member
i understand, i built my on reflector out of shinning sheet metal from home depot, but here is where im cunfused at my light is hanging from the ceiling about 6 inches above the tank so where do u start measuring how far the light penatrates? Does it start from the top of the water or from the light it self? My tank is 20 in deep.
scsinet
Active Member
You usually look at water depth only. Light penetrates air pretty easily, so the 6" above the water isn't going to have much of an impact.
You've got a few things to think about though... first, do you have a glass shield between the water and the lamp? That lamp is awfully close to the water. A splash can easily shatter a hot lamp.
Also... your reflector... as Stan said, 20" is the general rule of thumb for halides (though I'd have probably said 18"). This is with an average reflector. Your reflector is not average, it's homemade. The bend angles matter to a tremendous degree. I don't know how carefully you measured your angles or if/how you figured them, but unless your homemade reflector is the exception and not the rule, you might not be getting the penetration you want out of this lamp.
I don't buy the expensive lumenarc or other such high end reflectors myself, but I once made reflectors out of the same type of stuff you did, and when I switched to just the basic batwing/spider reflectors it made an enormous difference. Plus, steel (even galvanized) can and will rust in a saltwater rich environment.
You've got a few things to think about though... first, do you have a glass shield between the water and the lamp? That lamp is awfully close to the water. A splash can easily shatter a hot lamp.
Also... your reflector... as Stan said, 20" is the general rule of thumb for halides (though I'd have probably said 18"). This is with an average reflector. Your reflector is not average, it's homemade. The bend angles matter to a tremendous degree. I don't know how carefully you measured your angles or if/how you figured them, but unless your homemade reflector is the exception and not the rule, you might not be getting the penetration you want out of this lamp.
I don't buy the expensive lumenarc or other such high end reflectors myself, but I once made reflectors out of the same type of stuff you did, and when I switched to just the basic batwing/spider reflectors it made an enormous difference. Plus, steel (even galvanized) can and will rust in a saltwater rich environment.