Lighting Upgrade Concerns

[Super_Blueberry]

So I'm looking at swapping out my 6 current T12's with a custom LED array, and I'm curious what results (either good or bad) you experts might expect this change to bring.

It's a 100g heavily planted tank. 24" from lights to substrate. Dirted, PPS Pro daily ferts with CO2 injection. Currently my T12's produce just under 2200 lumens each, for a total of just over 13,000 lumens. Looking at replacing those with 8 30w chips that produce 2800 lumens each, for a total of over 22,000 lumens. I want to stick with 8 chips to eliminate any spotlight effects, but do I have to drop the wattage?

I currently have a hard time getting enough light at the substrate level to grow a lot and I'm hoping that the increase will help WITHOUT making the upper level a pure algae farm.



Thoughts?


Sent from my iPhone using Aquarium Advice

 

[Brian_Nano12g]

I'm not too familiar with DIY LEDs, but 30w chips seems awfully high. Typo? For high output diodes, such as CREE, they're usually 1w or 3w max. But either which way, once you figure out what you need exactly, I'd aim for high output but definitely get dimming capability with either a manual type dimmer or controller. So in case you overshoot your desired light level, you can simply dim and fine tune, until you have light, ferts, and co2 balanced.

Also do yourself a favor and get some red diodes in the custom array. Something like 660nm. All white chips tend to look a little cool and produce a lot of blue wavelength due to the nature of most "white light" emitting chips actually being blue diodes with a yellow phosphor on it to produce white light. This, IME, produces low CRI and washes out colors, making your fauna and flora look drab by comparison. Also consider the angle of your optics. You may need more focused ones to adequately get light to the substrate depth. And to be sure, I'd measure the PAR rather than the lumens to determine if you're on or around your target light intensity at substrate. 24" is a long distance for light to penetrate. Might be worth it to rent a PAR meter when working with DIY LEDs.

 

[Rpeinhardt]

Brian beat me to the points I'da made so I'll just +1 them:

640-660nm is your chlorophyll B absorption frequency. I think the peak is 642 nanometers.

Chlorophyll A is....450nm? I forget.

Hit those and use a green LED to keep the overall light white-looking.

You're going to need to watch out that you're not hitting your tank with too much light and growing algae if you focus on PAR frequency. One watt of PAR light is more potent than one that falls outside.

 

[Super_Blueberry]

Here's a snapshot of the chips I was going to use. Perhaps it would be better to use more chips but of smaller wattage, and mix in some reds and greens?


Sent from my iPhone using Aquarium Advice

 

[Rpeinhardt]

I'm unfamiliar with Tai Da Hong. I'm guessing you chose that brand for cost purposes.

I'd be wary but I'd the savings are significant, hey why not?

I'd skip forget trying to hit specific wavelengths with those. It doesn't look like they give you a spectrum analysis of the units anyway.

Maybe mix warm and cool whites to try and hit those lengths better but, without knowing more, it's all just conjecture.

What's one of those guys cost?

 

[Rpeinhardt]

Also, how much heat do they put out compared to your T12s?

 

[Brian_Nano12g]

Just make it easy and go to BuildMyLED.com and go for the Dutch XB model. Or dual units of the non-XB with focused beam angle optics.

 

[Brookster123]

Just make it easy and go to BuildMyLED.com and go for the Dutch XB model. Or dual units of the non-XB with focused beam angle optics.

Truth!!

Sent from my SAMSUNG-SM-G900A using Aquarium Advice mobile app

 

[Super_Blueberry]

They come to around $2/each for a 30W chip. Cheap enough to try

http://m.ebay.com/itm/221527896128

Not necessarily the exact ones I would buy, but it's my starting point

 

[Super_Blueberry]

I've looked at buildmyled before, but the problem is I don't know how wide they are. I need the 60" model, but will one do it? Do I need 2? 3? 4? At $400/each that will add up fast....plus I don't know how many will physically fit in my hood. $1200 vs $60 and some time tinkering.....

This is why I'm asking around


Sent from my iPhone using Aquarium Advice

 

[Brookster123]

They'll build you whatever you want/need. Call them up, tell them and they'll build it! Easy! My fixture is about 3"wide, very sleek..

Sent from my SAMSUNG-SM-G900A using Aquarium Advice mobile app