[customtanks]

In terms of watts what is a good wattage to shoot for a 70gal tank with DIY LEDs so it can be a high light tank? I would think 3w per gallon would be over kill, i do have a PAR meter. Im jus trying to get a ball park figure on what others r running. I have a couple drivers 2-50w an about 3-30w drivers wanna se what i should use as a steping stone to start off with.

 

[Yo-han]

It really depends on the LEDs in my experience. But I used two TMC grobeam 1500 (30W each if I recall right) for the same size tank and was able to grow a lush glosso carpet. I don't think you need to go over 1 WPG unless you use some very inefficient LEDs.

 

[marty93aus]

If you have a PAR meter, I would temporarily wire and install the drivers, LEDs at the height you would like, and then get a measurement from your meter to the lowest point of your substrate? I think you'll get different readings from a filled tank and an empty tank, 70g is a lot of water for a test, but you just want a rough idea?

I'm using 2x current satellite + fixtures and 1x normal current freshwater fixture, all 3 lights are LEDs.
The current sat + are both rated for 60W each and the normal current sat is rated for 18W. They don't pull those wattages.

The lowest point of my substrate is 20inches from my lights, the tank is filled and planted. HC being the most light demanding plant I think. Current USA says I have a PAR of 64mm at 20inches, with all three lights turned on.

thats a very rough idea I can't compare my lights to yours as well as my tank.

I am a beginner hopefully my idea is a good idea?

Cheers.

 

[customtanks]

It really depends on the LEDs in my experience. But I used two TMC grobeam 1500 (30W each if I recall right) for the same size tank and was able to grow a lush glosso carpet. I don't think you need to go over 1 WPG unless you use some very inefficient LEDs.

Tanks for the info guys, what u guys gave me in info is what i was thinkin about running 60w-80w more the later tho.

 

[TropTrea]

With LED's there is no direct number in conversion between Watts and the amount of light you will get because of the range in efficiency of LED's and the differences in the spectrum's. As an example you can find LED's that give less than 60 lumns per watt of power as well as some that now approaching 200 lumns per watt of power. Then you have the spectrum differences where some create more light in the green range that is useless for plant growth and others that only produce a marginal amount of green light.

To give you a comparison on a reef tank that 90 gallons I was able to get PAR reading at the substrate of 100 with 150 watts of LED lighting using Cree XP-G neutral White and Cree XP-E2 Royal Blue LED's. This combo would not work for a fresh water planted tank. On the other end of the spectrum I'm now running only 2 Watts of Neutral White lights on 10 gallon planted tanks with mainly horn worth that is growing out of control also using XP-G2 LED's.

On some of my earlier builds with LED's with none brand name LED's I could not get a PAR reading of over 40 at the substrate of a 75 gallon tank using 240 watts of LED's.

So right now if your looking for efficiency I would say it is a lot of doing research on what your buying for LED's. Right now I like using Neutral Whites because they have a much stronger red spectrum than cool whites. Others use Cool Whites and supplement them with red LED's. And still other use Warm Whites and supplement them with blue LED's.