lighting for 20H

[guppygirl]

Hi all,
I've been investigating lighting for my heavily planted 20 gallon. I was looking in Foster and smith and I though maybe instead of doing CF's I could do NO fluorescents. So I was thinking 2 double tube strip lights. It says it fits 2 24" bulbs, which means I would get exactly 4 wpg. I know this is still in the 2-4 wpg range, but is it too much? I am planning to add co2 by DIY either with the hagen natural plant system or soda bottle.
Also, what bulbs do you recommend if it isn't too much?
Thanks!
Robin

 

[Silly me]

Full spectrum lights with a color value of 5500K to 6700K is best.. there is lots more option but not woth the extra money..

 

[guppygirl]

So it isn't too much light??

 

[Nisha]

That does sound like a lot of light to start with but your plants will love it. You are definitely going to need CO2 and good substrate/ferts. Also make sure to plant heavily or you might end up with severe algae problems. Your plants will get huge so be prepared to prune a lot as well.

If you feel that it's too much light once you set up, you can always put the lights on a timer and restrict the time they are on.

Good luck!
~Nisha

 

[Silly me]

its the same I have over my 15g. I have 4.8wpg and its not to much light at all. I do have a lot of watersprite in the tank, but dont have a algae problem. or ever had..

 

[Discomafia]

Don't forget... the larger the tank size, the lower the wpg required. Plus the wpg rule works only for tanks 30 gallons or more. And since the tank is a 20H, you've got to make up for that additional height.

And like Silly me mentioned, 5000K to 6700K is the correct rating you should be looking for as the light it emits is of the same frequency of midday sunlight. Be sure to plant your tank full of plants right from the start, which will allow you to get a feel as to what plants you can and can't keep, also it'll let your tank get that early advantage over algae.

C02 is the other one, so make sure you've got it up to notch, and if you're wanting to really plant your tank, make sure to restrict surface agitation so that means no airstones or other things... Good luck, and keep us updated with a pic or two when you've got it all sorted out.

 

[guppygirl]

keep us updated with a pic or two when you've got it all sorted out.

Will do. I'm planning on using either pure onyx sand or flourite on the bottom layer and onyx sand on top. Is this ok or should I just use all onyx sand?
I think I'll definitely get the two NO fluorescents.
The measurements on the 20 are 2 feet long, 16" high and 1 foot wide. I don't know if this is a 20H, but I know it's not a 20L!
The filter I think I'm going to use is simply a small powerhead with a quick filter with bio-balls in it attached to the powerhead. Will this create too much surface agitation?
Thanks for all your help so far guys!! I really appruciate it.

 

[guppygirl]

anybody??

 

[Silly me]

Sounds good. I just use flourite, but thats just me..

also your filter idea sound great..

 

[Nisha]

If you use flourite on the bottom and onyx sand on the top, the onyx sand will end up on the bottom anyway because it's smaller. Better to use all onyx sand, all flourite or 1-2 inches of flourite with some normal gravel on top. I used the latter and it worked well for me.

 

[guppygirl]

Yeah, now I just have to convince my mom to buy another bag of onyx sand! Oooh, now I have a bunch of ideas... gotta go write them down!!!

 

[NikkiY]

... the larger the tank size, the lower the wpg required.

I don't quite understand this. Why the wpg be lower for larger tank? Is there some kind of fast rule to follow to calculate the amount of light for a large tank?

Thanks.

Nikki

 

[Nospherith]

... the larger the tank size, the lower the wpg required.

I don't quite understand this. Why the wpg be lower for larger tank? Is there some kind of fast rule to follow to calculate the amount of light for a large tank?

Thanks.

Nikki

I think it has something to do with intensity. Lets say you have 120w over a 60g. That's barely 2 wpg, but it's still giving you alot of intensity and you should be able to grow most plants --(well, all but the high light plants I guess)--. On the other hand, if you have a 2g nano, you could have 6w of light and technically that would be 3wpg, but it's only giving you 6w of intensity, which isn't going to grow much.

 

[Yenko]

I'll just use the Takashi Amano explanation:

The smaller the tank, the more WPG it requires. Takashi Amano's smallest tank, with a volume of one liter has an 8 watt light. That's roughly 32WPG. Unheard of, right?

If you go up to a 10 gallon tank the lighting is around 6WPG. Seems pretty excessive, but if you go up to a 70 gallon tank, he has around 1.2 WPG, which most sites would call insufficient for a tank like that, despite the fact that he grows extremely high light species like Glosso and Riccia Flutans in the tanks.

For my 70 gallon tank I'm going with 120W of lighting. The canopy will be DIY and use 4' 40W T8s. I will design it to allow at least 5 of those tubes to be installed if I want to allow 200W, more than twice what Amano would use. That's because eventually I plan to elevate the fixture 6-18" above the tank level to allow emergent growth. When the tank reaches its final plan, it will be using no CO2 enrichment; the only completely submerged plants will be slow-growing low light plants that would gain little benifit from CO2 enrichment anyway. Besides, the nature of emergent plants is to completely abandon leaf growth underwater and merely use the submerged portion for nutrients and support, which would reduce CO2 consumption.

 

[gale]

So how many WPG would I need for my 20 long? I don't want so much that I need co2 but enough so at least the low and maybe even some mid-light plants would grow without being too leggy.