DIY Led 10 gallon build thread/alternative diy co2 thread

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krap101

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I think it's about time I finally started this. I'm probably going to be running 12ish 3w leds (3.7v ~800ma) for a total of ~3.6wpg and diy co2. Since I can't take my 29 or my 40B with me to school, I want to be able to continue my planted tank at school, and 10 gallons don't have very good lighting to start with.

I'm also considering finally starting my baking soda co2 system. When you heat baking soda, it releases co2, but it needs to be pretty hot. I'm wondering if could run copper pipes from the heatsink to a container with the baking soda, and use the heat from the leds to power my co2. If not, I can use a peltier (thermo electric cooling) where you run it at 12V, one side gets very hot, and the other gets very cool. Electricity isn't a problem, so the efficiency of the peltier shouldn't be an issue. One problem I see possibly is condensation, but we can worry about that later. I guess baking powder can come in a liquid activated form, where when you add a liquid, it will begin releasing co2. This could work very well for this application. Either add the liquid at the beginning, add a needle valve and some container that can keep up with the pressure.

I'll post a little more once I get my budget approved (parents) and find a suitable power source. If I make two strings of 6 leds, that'd be 1.6A and a little over 22V, which is reasonable. I'm hoping to be able to be close enough to the power supply voltage to be able to not have to have a resistor in the series, but any suggestions will be helpful

Thanks!
 
I'm a little confused about lighting equivalencies. I've read from a few sites, that 1wled =4w normal as well as 12w=25w and 25=175w. Right now I'm leaning towards 4-6 normal watts per led watt, but can anybody confirm?

Aquarium Lighting; Kelvin, Nanometers, PAR, Bulb, Watt, MH, LED, Light Basics.

That site gave off a few of the numbers, and others came from random forum posts around the web.
 
Nano-Reef dot com also has a large DIY LED community and guides. 12 3w at 800mA is going to be a lot of light for a 10 gallon. I'm planning on growing SPS with the same fixture over a 12g JBJ. You might want to invest in a dimming puck/driver to photo-acclimate.
 
I just posted that just before you posted that :p

Anyways, I'm trying to find out. I'm wanting to be in the 3-5w range, but I'm having trouble finding consistent information. Now I'm thinking I may be able to cut that number in half, going with a safe estimate of 3-4 watts. That means with 6 leds, I'll have an equivalent of 54-72w...
 
Good article, haven't seen that around. I'll have to sit down and give it a once over.
From what I have seen there is no good comparison to differentiate LEDs and the common lighting systems now. What really matters is the PAR values, and unfortunately the meters are hard to get your hands on so limited knowledge is available. I would look through examples on some sites, and look for where people have recorded PAR values and use that to judge. If i recall correctly, a tight grouping of 4 LEDs had something around 600 PAR at maybe 8" and 1000mA. I'll look.

EDIT: haha you did it again. Were you thinking all whites or what? I'm not exactly familiar with growth requirements of planted tanks.
 
You need all whites for plants. And maybe 1-2 blues just for color enhancement. The newest spectrum that's all the buzz is 9325k bulbs. So I'm guessing 3x6500k 3x 10000k and 2x blue is sufficient.
 
Ok i drastically overstated my last post. 300 PAR around 8" and 700mA.
NEW LED PENDANT FOR PICO - Nano-Reef.com Forums
Still though, plenty to grow plants.

If you use the methodology like in that RC build (like i did) and use independent power and pucks, you can only run them in strings of 6. (without getting into weird voltage power supplies) If you use something like a meanwell though, you can run larger strings, and is AC powered, so they are super easy to wire up.
 
I was thinking of maybe using a notebook power supply, and burn off the extra voltage as heat?

I was planning on getting the cre xre p4 in the cool white color. (~6500k I think)


I suddenly got confused.. I was thinking that the leds would draw as much power as they needed (so I won't need to control amperage with my laptop power supply/charger, but how would I control what amperage I'm running at without something like a buckpuck? Could I even?
 
I was thinking of maybe using a notebook power supply, and burn off the extra voltage as heat?

I was planning on getting the cre xre p4 in the cool white color. (~6500k I think)


I suddenly got confused.. I was thinking that the leds would draw as much power as they needed (so I won't need to control amperage with my laptop power supply/charger, but how would I control what amperage I'm running at without something like a buckpuck? Could I even?

You can limit current drawn from the laptop PSU with a resistor on the cheap. Or you can build a constant current driver. If you are not very good with circuits and schematics, I would suggest a resistor or a commerical driver.
Here is a little example of how you design a simple circuit:
6 leds that drop 3.4v when driven at 1A of current...
24v 6A SMPS

Each led will drop 3.4v. So that is about 22V total.

Ohms law: V = I*R
24V-22V/1A = 2ohms

So youll need a 2ohm resistor to limit the 6 led string at 1A. This neglects wire resistance and impedences.

Your resistor will dissipate some power.

P=I^2*R
1A^2*2ohms = 2W of power dissipation. So youll need a power resistor rated for more than 2W of power dissipation to limit the string current to 1A
So, why cant you use a buckpuk or meanwell?

Matt
 
When I started to think about this project awhile ago, it seemed so much easier just to use a laptop power supply. I haven't thought about it (rethought) in depth yet, but I still have my original assumptions (not sure how well founded they are though)

If you're suggesting a switching mode power supply, then wouldn't I be able to ignore the resistor at the end?
 
When I started to think about this project awhile ago, it seemed so much easier just to use a laptop power supply. I haven't thought about it (rethought) in depth yet, but I still have my original assumptions (not sure how well founded they are though)

If you're suggesting a switching mode power supply, then wouldn't I be able to ignore the resistor at the end?

Nope, youll need a resistor for any PSU you choose. Or some other way to control current.

Diodes will attempt to draw enough current to destroy themselves.

You are thinking of a PSU + controller combo such as a meanwell LED power supply.

Matt
 
Now that that is out of the way (thanks :)) what power supply would you recommend?

If I go for the 24, I'll need a 1.8 ohm resistor, and (.8^2*1.8 at ~1.152 watts.)

If I go for the 22, will the last led in the string just take up the slack and be dropped to 3.5V? or will it not work?

I guess I'm onto buckpucks now... Buckpucks basically make sure only 800ma (I think they only come in 700ma or 1000ma flavors) gets through, and kind of protects your leds. Beyond that, they serve the same purpose as the resistors, right? If I remember correctly, the circuit has two paths. One path is if it is over the rated current, and it goes through something and is somehow lowered, the second path somehow boosts it (capacitor?) and I saw it on instructables awhile ago.
 
Now that that is out of the way (thanks :)) what power supply would you recommend?

If I go for the 24, I'll need a 1.8 ohm resistor, and (.8^2*1.8 at ~1.152 watts.)

If I go for the 22, will the last led in the string just take up the slack and be dropped to 3.5V? or will it not work?

I guess I'm onto buckpucks now... Buckpucks basically make sure only 800ma (I think they only come in 700ma or 1000ma flavors) gets through, and kind of protects your leds. Beyond that, they serve the same purpose as the resistors, right? If I remember correctly, the circuit has two paths. One path is if it is over the rated current, and it goes through something and is somehow lowered, the second path somehow boosts it (capacitor?) and I saw it on instructables awhile ago.

To drive 12 LEDs I would go with one of these:
Nanotuners.com

It will also allow you to dim the leds. Cheaper than bukpucks and more reliable.

Matt
 
So, the adjustable dimming function, that controls current right?

To me, it looks like the 60-24 will be the best option for this tank and others, as I will be able to run 3 strings of 6 leds at 800ma and 3.7v if I choose. If I get the 60-27, I'll be able to run 21 leds at ~750ma and 3.7v. If I wanted to one string of 12 leds, the 60-48 would work, but would not allow for any expansion to another string unless I pushed the leds down to 650ma.

Your thoughts on this?

Also, I read somewhere that mixing strings of leds is a bad idea, so if I wanted to add moonlights, would I have to use an entire string?
 
So, the adjustable dimming function, that controls current right?

To me, it looks like the 60-24 will be the best option for this tank and others, as I will be able to run 3 strings of 6 leds at 800ma and 3.7v if I choose. If I get the 60-27, I'll be able to run 21 leds at ~750ma and 3.7v. If I wanted to one string of 12 leds, the 60-48 would work, but would not allow for any expansion to another string unless I pushed the leds down to 650ma.

Your thoughts on this?

Also, I read somewhere that mixing strings of leds is a bad idea, so if I wanted to add moonlights, would I have to use an entire string?

Yes, the dimming feature controls the current draw. You can look at the current/voltage curve of the LED to see what voltage it will drop at a given current draw. They ought to drop 3.7 max when drawing their maximum (safe) current.

If you are running all whites, id run one string and use one meanwell. If you have different colors and want to mix the colors (and have the money) you can use a meanwell for each string.

Each string will need its own meanwell.

Let me know what you plan to do and I will be able to help a little better. ;-)
How many leds total? How many colors? What functions do you wish?

Moonlights are a bit more tricky, as you usually just use a few. If you have a long tank and need several, then another meanwell (cheaper non dimmable version) would be a good choice.

MAtt
 
Maybe moonlights aren't the best idea, since I'll be living in the dorms, and my roomate might not like the blue reflection on the ceiling.

I'm not exactly sure on how many leds I want yet.. I'm hoping to have a medium-high/high light tank, without totally burning my tank up with too much light. I forgot about the increased efficiency/watt, and the first plan was to have 12 in a 10 gallon tank (fw planted) and that would have given me 36 leds watts. The more conservative estimates are 3-4w/wled, so this might possibly give me over 100w of "real" light. If I get 6 leds, 18wled, that's 54-72 "real" watts, which is kind of but also reaching sun-like levels, if you know what I mean :p, but now I'm worried about having 4 leds over my fish tank with coverage and all... I want to do this right, but at the same time not spend more money than I need to. I've allotted maybe $40 for the leds, and now $32 or so for the meanwell, and I still haven't even considered heat sink and possibly optics costs.

I'm hoping to eventually possibly get them running on a controller like here. It seems like if I tried using an real time clock, it may make things easier.

http://www.aquariumadvice.com/forum...hts-sunrise-sunsets-and-cooling-130818-5.html

You said I'd need a new meanwell for each string. Does this include strings of same color? I was counting on the 2.5A and the 24V, so I could run two strings of 6 or 2 strings of 7 when I try to make this project bigger (29 and 40b tanks) I'm using strings as in each branch of a parallel circuit. I'm hoping you're meaning strings as in different colors, or making a larger light will be more complicated than I thought.

I'm expecting one color (I'm not a reefer :p) using 6500k cool whites. I'm almost afraid some of the spectrum will be left out, as a side effect of how leds work, and it will wash out the color of the tank. As for total leds, I'm thinking 4-6 should work. I'm also wondering about running more leds at a lower power (current). 4 leds seems a bit low, but then again, it is only a 10 gallon.
 
All of these led power supplies run just one string at a time. A 10g tank is going to require 16 leds or so. The main concern here is getting the light coverage. I made an LED light for my 7.5g reef that is a 12in cube. I needed 2 strings of 4 leds to cover the 144in^2 of area.

Youll wind up spending more than you think to do this right. ;-)

You are off to school, right? You should be eligible for financial aid. :-D

I spent about $150.00 to build my light and its a bare bones light. No fancy fixture or anything to enclose it.

Matt
 
I'm looking to just use the heatsink as the "fixture" and create some legs out of acrylic or something (aluminum maybe)

I'm wondering what is preventing me from running a parallel series off this driver? I'm not trying to be difficult, but I am a little surprised. After a quick search, the closest I have come to the meanwell unable to run parallel circuits was that if one led goes out, you could possibly damage the rest of them.

Power supply question - CandlePowerForums

"They're using another meanwell driver and like you said Bob, it's a 48v(max) driver but it's a bunch of watts and you can run parallel strings off of the initial series and the driver is dimmable. It's a plus for them but sounds like a pain to me."

This won't be a reef tank, so 16 leds at 3w is going to be a ton of light. I'm not sure about the angle on these leds (I'm sure there's multiple), but if I got 6 leds, would I then need optics to spread the beams out to avoid spotlighting? Is that the reason for the need for 16 or is it that the estimates for t5 equivalent wattage was a little over and maybe closer? I'm trying to get to around 3.6wpg, and from what I understand, I'll need 36 "real" watts, or 9-18 "led" watts, depending on the conversion between t8/t12 and leds. T-5ho is like 1.3:1 and t5 is like 1.35:1 or something like that. I read that leds were like 3-4:1 and what I'm basing most of this build on.

Let's start the calculations for coverage. Assume I need to cover 200in^2, and my leds will be around 14" high. My led's will have a 90 degree viewing angle (off the cree web site) so that means that (using trig) each circle will have a radius of 14". With a 90 degree viewing angle, it will be impossible to have even coverage as well as keeping all the light in the tank. I'm guessing a 2x3 formation will work well, or a 2x4 (I think this will give the most even coverage)

I'm still at a loss to how much more light (I guess par is the craze these days) that an led will produce compared to a t5ho or a t-8/t-12. If I used 16 leds (48w) over a 10 gallon, even under normal standards it is too much light, but since these are high output leds, it's worse.

Don't think I'm ungrateful, (I really am), but I'm just trying to figure this out, and I guess I learn the best when I am debating (my family gets really annoyed). People like you make people like me seem smarter than we are :p. Smartness by proximity? Virtual proximity?
 
I'm looking to just use the heatsink as the "fixture" and create some legs out of acrylic or something (aluminum maybe)

I'm wondering what is preventing me from running a parallel series off this driver? I'm not trying to be difficult, but I am a little surprised. After a quick search, the closest I have come to the meanwell unable to run parallel circuits was that if one led goes out, you could possibly damage the rest of them.

There is another thread here when we discussed exactly why parallel series isn't your best option. Off the top of my head I can't remember exactly why, but its not. Series is the best way to do this, parallel can have fluctuations that can blow the diodes if you aren't careful.

Power supply question - CandlePowerForums
"They're using another meanwell driver and like you said Bob, it's a 48v(max) driver but it's a bunch of watts and you can run parallel strings off of the initial series and the driver is dimmable. It's a plus for them but sounds like a pain to me."

This won't be a reef tank, so 16 leds at 3w is going to be a ton of light. I'm not sure about the angle on these leds (I'm sure there's multiple), but if I got 6 leds, would I then need optics to spread the beams out to avoid spotlighting? Is that the reason for the need for 16 or is it that the estimates for t5 equivalent wattage was a little over and maybe closer? I'm trying to get to around 3.6wpg, and from what I understand, I'll need 36 "real" watts, or 9-18 "led" watts, depending on the conversion between t8/t12 and leds. T-5ho is like 1.3:1 and t5 is like 1.35:1 or something like that. I read that leds were like 3-4:1 and what I'm basing most of this build on.

16 seems pretty excessive to me. I honestly think 12 is more then enough for that size for a planted. I think you are getting hung up looking for numbers that aren't really there as far as conversions go. Let me mock up something and we can take a look at it.

Let's start the calculations for coverage. Assume I need to cover 200in^2, and my leds will be around 14" high. My led's will have a 90 degree viewing angle (off the cree web site) so that means that (using trig) each circle will have a radius of 14". With a 90 degree viewing angle, it will be impossible to have even coverage as well as keeping all the light in the tank. I'm guessing a 2x3 formation will work well, or a 2x4 (I think this will give the most even coverage)

I'm still at a loss to how much more light (I guess par is the craze these days) that an led will produce compared to a t5ho or a t-8/t-12. If I used 16 leds (48w) over a 10 gallon, even under normal standards it is too much light, but since these are high output leds, it's worse.

Again, I think 16 is way too much. I would guess you are looking at 350+ PAR where some of these beams cross over in the middle.

Don't think I'm ungrateful, (I really am), but I'm just trying to figure this out, and I guess I learn the best when I am debating (my family gets really annoyed). People like you make people like me seem smarter than we are :p. Smartness by proximity? Virtual proximity?

No worries, asking lots of questions is never a bad thing.

So..much..text.. its too earlyyy.
 
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