Originally Posted by
Mombostic
Also, I did see that I have priced the Sunpod Pro, which is the 500 watt model. On my 90, is the 300 watt sufficient? Is mh really that much better than pc? That model is a lot cheaper. I read the quote way back up there that is was better even than the 520 watt pc--I'm not arguing, but could someone explain that to me? I don't exactly understand why that is. You here everyone on hear everyone on here talking about watts per gallon and all of that, but I have always wondered about the thinking behind that. For example, 55 and 75 gallon tanks are the same depth, so isn't the stuff in the water getting the same amount of light from a fixture, even though the watts per gallon goes down?
Wow, who would have thought you'd actually have to THINK to be a marine hobbyist????
Exactly watts per gallon mean nothing. 10" below the light source is 10" below the light source wether you have a 30g or a 240g. A better method is to use tank depth and length. anything 20" or less there is no need to use anything but 150/175 watt lamps. from 20-24" I still say for 90% of livestock they are still okay if you use quality bulbs but 250 watt bulbs gives you more placement flexability and more importantly in the case of SE bulbs alot more bulb choices especially german style (aqualine and ushio are the only commonly available 10-14k german style 175 watt bulbs). very few people need 400 watt bulbs and the problems that comes with them (heat, cost and scortching non high light demand corals that arent near the bottom of a tall tank). Perhaps a 30" tall SPS dominated tank with anything else placed on the sand bed. The length standard is one bulb per every 2ft of aquarium length (and front to back if you actually have a tank 3ft back to front). You probably want to stick with this on DE bulbs but you certainly dont have to with SE bulbs (what if you have a 5ft 100g
). with good reflectors, adjusting bulb height and no light blocking center bracing you can easily get away with two SE bulbs over a 5ft or 6ft tank.
Basically if money is a concern I'd recommend you get the 300 watt sun pod for your 90g. you will still be able to keep most anything you want. The only things you wont be able to do are illogical anyway (keep the highest demand SPS corals at the bottom of the tank. people with 400 watt bulbs dont do this). and even if you could keep the same things with that 520 watts of pc lighting (many of which you can and cant) they wouldn't grow or strive nearly as well with just that 300 watts of Metal Halides so yes they ARE that much better! rarely does anyone who starts with a pc lighted reef tank end up sticking with pc (unless they have a small tank 30 gallons or less where MH isn't as practicle or neccessary).
