Advice on lighting for my 300gal plywood build

[oblrman]

I posted the following request in my plywood build thread (which can be seen here: My 300 gallon tank build) but havent gotten any responses yet. So I thought I would come to this section and ask the planted tank. Thanks!

So we have began work on the tank itself and I will be posting pics soon.

However, we need to start planning the hood so I can get materials for it.

I contacted the guys at fishneedit.com because I liked the prices on their lights and the reviews on MFK were generally positive for them. They said that I should consider getting 3x of the 250w metal halides or 2x of their T5 + metal halide combo (seen here ) since the tank is so deep. But I wanted to see what other folks think.

I know that there is going to be a TON of heat generated so we are planning to have a fan venting the hood. In fact I will probably put the fan on a thermostatic switch. In addition, I will have a thermostatic switch for the lights that will turn them off if the temp in the hood gets to dangerous levels.

Oh, I would like to plant med to high light requirement plants. And I will be doing a CO2 system as well.

 

[mgamer20o0]

you might want to email tom barr. i never had a 32 inch tall tank. that might play some factors into it. with fans you should be able to remove a lot of the heat from the mh. what plants are you look at for this tank? my 120 i started with a lot of medium light plants i couldnt keep up with that high growth and ended up with lower light easy growing set up.

one thing with larger tanks it takes less light to do the same thing. a lot of people talk about wpg but with bigger tanks those types of rules just break down. wish i could be more help but i hope it points you in the right way.

 

[hybridtheoryd16]

I seen a thread on another site a while back where a guy built a wooden canopy and had 12 26watt cfl daylight bulbs above a 265g and he was able to grow alot of plants that suprized me.

I wish i could find the thread to link you but I can't. If I remember correctly he had 250 bucks in the entire canopy and light set up. Pretty cheap in my opinion. And may be a option for you.

Speaking of tom barr he has a thread floating around some where on his site about the minimum thresh hold of light on tanks to grow plants. And he speaks alot about how larger tanks don't need what smaller tanks do.

And its true. My 5.5g tank has 30 watts of 6500k light above it at 5.45 watts per gallon to get my glosso and hair grass to grow properly. And i am able to grow the exact same plants in my 55g with 130watts of PC 6700k lighting at 2.36 watts per gallon.

So I would be willing to bet that you could grow what ever you wanted with the old 2 watt per gallon deal on your 300g. And you would be able to grow quite a bit at just 1 watt per gallon.

When building a large set up like this you may want to keep in mind the price involved in replacing the bulbs. Most plant guys say to replace your bulbs every 8-10 months. Because they loose alot of the lumens in that time period. I change mine yearly and I do notice a big difference but the plants don't seems to mind much at that point.i know MH bulbs are fairly expensive, so with those it may run you a couple hundred bucks to replace all the MH and t5 bulbs yearly or so. Where as cfl's can be picked up at walmart for 6-8 bucks a 4 pack. Just food for thought.