High-Power LED Fixture for a Planted Tank

[BigJim]

It's been a busy week coupled with a case of spring fever, so my tanks were a bit neglected this past weekend. I'm planning to get to them tonight and get some pictures. In the meantime, here's a quick literal update:

I didn't get the CO2 tank for my birthday, but I got $50 towards the purchase of one. There's a fish swap/flea market next Sunday, so I'll scout around there for a deal and hit the internet if I can't find anything. I'm thinking at least a 10lb cylinder so I can possibly hook up a couple tanks.

I still need to pick up a phosphate and a new nitrate test kit, so I haven't adjusted my ferts at all. The high-light plants aren't growing as quickly as I'd expected. I'm hoping it's just a shortage of carbon and not a light deficiency (or possibly excess).

GSA has taken over the front glass again. It's not thick enough to look very green, but it makes the tank look cloudy.

The najas grass and the mystery plant are running rampant. The mystery plants is over two feet long now and is starting to branch out. I still haven't seen any roots, but I might try planting it like a stem plant. The glosso has new, very short growth. I'm thinking about trimming some of the older, taller shoots and planting them to attempt a shorter carpet.

 

[Bige]

I rent my gas and tank from a welding shop for $3 a month. Idk if you have asked or have the option. Benefit is that you just exchange tank. No filling cost. If you own your own, you have to have your tank cleaned before filling. Maybe something to look into.

 

[BigJim]

I'd rather own my tanks. Renting wasn't that cheap around here and you still need to pay for the refills. My nearby welding gas supplier closed down so I have to find a new one. I've got three empty tanks from my cutting torch and MIG welder that need filling also, so maybe I'll get my act together and find one.

 

[BigJim]

Here's a FTS. I pulled out the water sprite before it takes over the tank, so it's looking a little bare.

Here's some glosso growth. There are a lot of shoots like this and they're all very short.

Here's a shot of the mystery plant. Still no sign of roots. I pulled it out and dumped it in my 40B.

Any suggestions for plants? I've found some deals on AquaBid that I might take a chance on.

 

[fort384]

Is the rotala w growing ok? I see 1 big stem in there...


How about some mid grounds like dwarf hair grass or maybe some more stems. Try some rotala m and really take that fixture for a drive

 

[Fdsh5]

Following: I also have the mystery plant in my gourami tank. Grows like crazy but never see a root.

Sent from my iPod touch using Aquarium

 

[BigJim]

The rotala is growing, but not very fast. The big stem you see is the tallest of the bunch. There's three or four shorter stems by the tall stem and another three or four stems behind the mystery plant.

 

[wmsky]

I followed this: DealExtreme: Customer Uploaded Photo Gallery - 2000mA 30W Power Constant Current Source LED Driver (85~265V)

It's in the customer images section on the LED driver page I linked to earlier in the thread. I have no idea how the poster figured out which resistor could be used to control the current, but it does work.

Hi,

Great thread. I've already ordered the LEDs and driver to build a more conservative version of your light. However, I have a question about the pot that you used, because there seem to be a contradiction between the schematic and the description of the schematic you linked to. The description says that when the pot is at 0, the parallel combination of 390R and 100R is applied. But the schematic says the pot is 1k - 10k. In that case, when the pot is at it's physical 0 point, it still has a resistance of 1k, so the the parallel combination applied would be 390R + 1100R. So, did you use a 1k - 10k pot, or a 0 - 10k pot?

Thanks.

-- Bill

 

[BigJim]

wmsky, welcome to AA!

Off the top of my head, I'm not sure what the exact resistance range is on the pot I used. I know the top end is 10k, but I'm not sure about the bottom end. I grabbed the first pot I saw with the 10k upper range because I wanted to finish the project and I intend it to be temporary.

Looking at the schematic again, I see your confusion. With a 1k-10k pot, you lose a bit of the lower end adjustment compared to the 0-10k pot. I wasn't really concerned with low-end adjustability since my goal was a high-light tank. I wired the pot so it's in the 10k position when the the detent clicks, so I know when I've got max current and the knob won't turn with an accidental touch.

Tank update: I think I scored big on Craigslist yesterday. I purchases a pair of 20lb CO2 cylinders for $35. One still has something in it too, but I don't know how much. The bad news is I think both tanks are out of hydrotest date. I have to do some more research. One tank is definitely aluminum, the other might be, but I didn't find any obvious markings when I looked the bottle over.

I'm hoping to see if my free CO2 regulator is in working order tonight, but it might have to wait for the weekend. The solenoid clicks when you plug it in, but I don't know about the actual regulator. If the regulator works, I'm a small powerhead and drop checker away from the high-tech CO2 system I swore I'd never get when I started with plants.

 

[Hatty]

What kind of thermal paste did you use? Thermal adhesive or thermal grease? Thermal grease is abundant around where I live but im afraid it wont hold the leds to the aluminum tube.

On a side note, I ordered less and a driver from a company called cutter electronics. The less are a little more expensive but they have a much larger selection. Plus they have an led driver with a potentiometer built in. In total I spent about $100 for 12 leds and a driver. More expensive than what you spent but I like the led color I chose a bit more.

 

[BigJim]

It's a thermal grease called Stars heat sink compound. I got one hundred 1g packets of the stuff from eBay for $10 not knowing how much I'd need. I only used about 1g, so I'm pretty much set for life on heat sink compound. I used 8-32 machine screws to secure the LEDs to the tubing. They're complete overkill and I had to use nylon washers to prevent shorts. Good luck with your build. I'll have to keep Cutter in mind. My brother wants an LED fixture now.

Another tank update:

I've got a whopping $35 invested and my ghetto-fabulous CO2 system is up and running. One of the tanks has about 50-60 psi and that's enough to get me going. I found a local fire extinguisher company that has hydrotest equipment. I'll call them today and find out what it's going to cost me for a test and refill.

My regulator is a total beater, but it was free. My friend's cousin bought a pet shop on impulse and doesn't mess with live plants. I found the regulator in the basement of the shop in a pile of old equipment. I tried to buy it, but he told me that if I didn't take it, he was going to throw it out. The chrome is peeling off and the outside brass is a bit green, but the guts are still clean. I may change out the gauges, but the needle valve and bubble counter work well. I've got the CO2 at one bubble per second for the moment.

I found an old Penguin 660R powerhead in my bucket of old equipment. Unfortunately the clip that holds the powerhead against the side of the tank disappeared a long time ago. I tried just hanging the powerhead in the tank by its cord, but I found a big hole in my sand Saturday morning because the powerhead angled itself a bit. I found a couple suction cups that seem to do the job. I've got the CO2 line pumping into the aeration port of the powerhead and I'm using the RUGF attachment to shoot the CO2 straight down.

Now I need to make a drop checker. Anyone have any good DIY designs?

I went to a local fish swap yesterday and scored some nice plants. I got a bunch of Alternanthera Reineckii (Telanthera Rosefolia) and a bunch of Nesaea Pedicellata. The vendor told me "You picked two of the most difficult plants I've got here. I usually don't even bother bringing the Nesaea because no one has a tank that will support it." I figured I'd save him an explanation and proceeded to tell him about the lights and the CO2 system. His response: "Enjoy your plants then. You're the first person I've had today that should be able to grow these."

Both plants were grown emersed, so I'm expecting a little die-off, but I'm excited to see how these do. I trimmed the guppy grass to prevent it from covering the glosso, but I'm thinking I'm going to pull the whole mess of it out and just have medium to high-light plants in the tank with the exception of the Crypt Lutea. I cut up my Crypt Parva into a bunch of plantlets. The giant wad was just too crowded. New growth was shading old growth. I've read recommendations to cut up Parva when you pull it from the pot. I was afraid to do it, but once I got one plantlet out, the rest just seemed to want to be separated. It came apart really easily with a good razor blade.

My goals this week are to get a CO2 tank refilled and get a phosphate test kit and a new nitrate test kit. Pictures tonight if I get a chance.

 

[Hatty]

I was thinking about attaching my LEDs with screws like you, but changed my mind and opted for thermal epoxy. I ordered some last night so hopefully it will be here soon. Anyways, by doing this, the amount of holes I'd have to drill were greatly reduced and the durability of the system is improved (less components to erode or break).

Speaking of shorts, I am also concerned about that. Contrary to your design, I'm going to install mine in the current, single T-8 aquarium hood thats installed on my tank. I like this for two reasons: 1. It hides the LED support and electrical system and 2. the glass partition keeps the water away from the LEDs to reduce the chance of shorts. I'm still debating whether or not I want to coat the exposed solder joints with rubber to completely seal the system. But since I have the glass partition, I probably wont.

Packing all the LEDs in a small area leads to problems of inadequate lighting coverage. I'm going to make it so the LEDs can be tilted to spread the light around, but it worries me a bit. Any suggestions?

 

[BigJim]

Pictures as promised:

Alternanthera Reineckii

Nesaea Pedicellata

Powerhead with UGF adapter

CO2 tank with regulator

Full tank shot

Hatty,
Look at the viewing angles on the LEDs. My Crees have a 90 degree angle. Some LEDs have a wider angle. Optics can help put the light where you want it. I left my solder joints alone because I have a glass canopy on the tank. My biggest concern with putting a bunch of high-power LEDs in a stock hood is heat buildup. I built my fixture frame out of aluminum for heat sinking purposes and it still gets pretty warm. Wrapping the LEDs in a plastic hood will make things worse.

 

[meegosh]

Now I need to make a drop checker. Anyone have any good DIY designs?

Quite possibly the cheapest drop checker in the world:

Simple DiY Drop checker for under $2.00

 

[BigJim]

Thanks meegosh! I think I've got the general idea down, so I'll dig through my junk box and see what I come up with.

I saw that people in that thread talking about changing out the drop checker solution. Is it necessary? If so, how often?

Also, how toxic is bromothymol blue? I've seen a lot of "not very, but I'm not sure" responses. I don't have much luck with suction cups and I'd hate to nuke my tank if/when the drop checker pops loose.

 

[fort384]

The solution will fade over time. I change mine out about every 6 weeks.

Not sure on toxicity of bromothymol blue. You might find an msds on it if you do a google search. I am guessing it isn't too toxic since it is pretty neutral in pH, you are only using a few drops, and even those few drops are highly diluted.

 

[fort384]

http://www.sciencelab.com/msds.php?msdsId=9927468

It looks as if it is somewhat toxic at acute levels... But it is a level 2 HAZCOM for health... And there is no LD50 which tells me that it is probably not going to cause a huge problem if 3-4 drops of it in an already diluted form are released into several gallons of solution.

Looks like there is a lot of anecdotal evidence out there too of folks who accidentally got some in their tanks and I didn't see any that reported negative effects.

 

[BigJim]

Thanks fort. That's pretty much what I found too. The "toxic to lungs, mucous membranes" statement in the MSDS scared me a bit. I guess if the tank gets contaminated, I have a bunch of activated carbon handy.

 

[BigJim]

My cheap CO2 system must be doing the job. I haven't caught the plants pearling, but I've seen a lot of bubbles rising, especially from the glosso. The algae buildup on the front glass has slowed and the thicker algae on the side glass appears to be receding. There's some new growth on the rotala and the moneywort and the telanthera and nesaea have both perked up. It's definitely encouraging me to get my act together and find the test kits I need to tune my fert regimen.

 

[mfdrookie516]

I am definitely going to petition the mods to change this title. I didn't realize it was a build thread for your tank! I'm kind of upset I haven't been following.

I do have to ask a question... and make a statement. Why don't you have a background? Aren't you right there recommending backgrounds every time somebody asks for a critique?

Once that glosso fills in, you're going to have a very nice looking scape. I kinda like that little cave thing you've got there... not usually a fan of resin decor, but I like that. Whats the plant over in the back left corner?