• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Is my DIY LED setup low/mid/high?


6 Nov 2015
calgary, alberta
I have a 40 liter tank.
I made a DIY setup using three cheap GU10 LEDs from Ebay.
Each bulb is supposed to have these characteristics:
- cool/pure white 6000-6500K
- 500-550 lumen
- 6W

I was under the impression that this light is more then adequate to grow plants. I though I have a medium to high light setup. The light fixture is 3 cm above the water and it looks very bright to me.
I use EI dosing method: dry ferts for macros, Fluorish for micros, Fluorish Excel for CO2, root tabs.

My barely surviving plants are:
- Anubias barteri (even anubais is not happy in my aquarium)
- Ludwigia inclinata var. inclinata (was told at LPT that is low light easy plant)
- Rotala wallichii (was told at LPT that is low light easy plant - now I know better)

- Is my lighting appropriate for my tank?
- Is it low, medium or high?
- Can you see a lack of balance?

Any ideas and advice is welcome

Last edited:
Until one of the experts answers this I would suggest you have far too much light for a non pressurised co2 tank. For example I have a total of 24 watt led lighting over a tank 80x60x40cn high

Most of the time the surface is covered in floating plants too. I wouldn't be surprised if 1 bulb would be sufficient for the low tech tank so I'd say you are in high light territory. If you started pumping the co2 in and had sufficient flow your plants would probably take off.

Sent from my GT-I9505 using Tapatalk
Are you also using DIY lights with regular bulbs?
Thanks for the tip.
I let only one bulb over rotala wallichii because it loves high light.

A strange thing - before installing the LEDs, i used three 50W halogen lights and both anubias and ludwigia showed good growth. Why do you think was that?

Now i have one LED over rotala and one halogen over ludwigia - hope they will like it.
My suspicion would be the same. 500 lumens do sound a lot over 40L when I am using 1400 over 180L with CO2. Can you dim your lights downs? You can also raise the light fixture to be further away from the water surface.

Sent from my GT-I9505 using Tapatalk
Unfortunately my lights are not dimmable and I can't rise the fixture (without making it unsafe - small kids).

What if I add some hardy plants to block some of the light?
- Anacharis Egeria densa - let it float
- duckweed

Not a big fan of either, but I maybe I can use these to learn how to balance an aquarium light+co2+ferts.
Later, I could start introducing plants that I really like and slowly removing these ones.
Good point Foxfish! I had 3 in my head for some reason? Must have been tired...
Lovelife..mine are tmc aquabars.

Sent from my GT-I9505 using Tapatalk
If you reduce the light then the demand for C02 is also reduced but high light required high C02!
Anubias do not require high light in fact they seem most happy in subdued light very often in the shade of over hanging plants.
You may get other opinions but I can light my whole lounge with three 6w Gu10 bulbs.
If you reduce the light then the demand for C02 is also reduced but high light required high C02!
Anubias do not require high light in fact they seem most happy in subdued light very often in the shade of over hanging plants.
You may get other opinions but I can light my whole lounge with three 6w Gu10 bulbs.

Thanks for the advice. I am experimenting with lighting for a couple of days now. Most likely will just leave 1 bulb and see what happens.

How long should I wait before changes could be observed in slow/medium/fast growing plants?
I basically copied this build .

Blimey, I don't want to patronise you, but please be careful if your setup is the same as that OP!

Even without the risk of dropping the unit in the water or splashes/condensation, some of those cheap LEDs from eBay are really really unsafe. As in live components at mains voltage exposed and touchable.
Those GU10 leds are constructed to fit a 220 volt fitting, they are not realy very good dimmable about that.. 🙂 But if you take'm apart you'll see there are no LEDS running on AC 220 volts. There is a little build in voltage regulator inside the fitting.

I've not yet measured the voltage output of the regulator, i suppose it will be as usual DC 12 or 24 volts.. If you are lucky and bought the GU10 leds whuch are assembled with screws. You could screw it open and take off the LED heatsink, cut of the regulator and connect them all to a DC 12 or 24 volt powersupply. Then it will be a lot safer to use and dimmable with a cheap PWM controler.. 🙂
But if you take'm apart you'll see there are no LEDS running on AC 220 volts.
Yes they are. A converter that size will not be 240V isolating and does not need to be. One of those wires on the left will be connected to one of the wires on the right, thus will potentially have 240V on it (with respect to earth and you as a person !). In fact, as the unit is supposed to be sealed, and thus during normal operation the user cannot touch any wires (dropped in fish tank is not normal operation), there is absolutely no need for the electronics to be isolating.
Yes they are.

🙂 So good to have you around.. Thank you!.. I did have to measure the output because of you and 😱 it regulates the voltage down around DC 7.3 volts. (Do you want it on pic? Since i have a bit of a hard time for you to believe me. 🙄 with the same respect to earth and you as a person !) So indeed i was wrong 😳, but than you could connect 2 in serie and run 'm on 12 volts.

Times change, sizes change.. 😉 Nicola Tesla era is rather developed also when it comes to regulators and their dimensions. 🙂
but than you could connect 2 in series and run 'm on 12 volts.
Not really. Unlike normal incandescent light bulbs LED's run on constant current (amps) not voltage (volts). This is why you have to have electronics between the voltage supply and the LED's. The electronics pushes for instance a constant current of 350mA through the LED's, assuming they are 350mA rated LED's. What you measured is the voltage drop caused by injecting say 350mA. This voltage will vary with temperature and age of LED's, but the current will stay 350mA.

If you really want the LED's isolated, you could ascertain the current going through the LED's (meter in current setting, but beware 240V knocking around) and buy a matching suitable LED driver. Then just wire the LED's up to the to driver. If buying from Ebay make sure from UK as cheap Chinese LED's drivers (like LED's) leave a lot to be desired in reliability (and safety !!).

350mA one here for instance.
https://www.tlc-direct.co.uk/Produc...w=350ma leds&gclid=CMmG2-Org8kCFcSfGwod3nEG5A
Depends on the kind of leds used ian_m, for example if you use high power cree leds which could have a forward voltage from around 3 volts and connect them in serie, you need 6 volts to run 2 of them and 12 volts with 4 and 24 volts to run 8 leds

and for example with SMD leds which run on 12 or 24 volts it doesn't matter how much strips you connect in serie it stays 12 or 24 volts only the amps/watts will go up and so need a powersupply able to deliver these watts. 🙂

With taking little units like this apart for diy experiments you have to try things.. Most of the times the internal components tell you zip and are blanc with no descriptions. I only saw a +/- sign at the output, so it told me it's a tiny voltage regulater/converter from AC to DC.. 😉 In my case this disessambled UG10 unit contains 3 leds and the tiny power supply converts the ac 220 to DC 7.3 volts fluctuates a bit.. So make it 7.5 v. Didn't inspect the plate the 3 leds are soldered on, but i wont be surprised if it are 3 cree leds in serie with a forward voltage of 2.5 volts. Maybe 3 volts and it might run on 9 volts to without a problem.
All LED's are current based, there is no other type.

LED strips generally have resistors to limit the current, which wastes power, which is why LED strips are not that efficient, but can be driven directly from 12V. Bigger LED bulbs generally have a power supply in them, so they can be run from constant voltage.

Below is the transfer characteristic of a white 500mA LED, blue line is at low temperature and red line at high temperature. Thus say 4V will produce 500mA when cold, but will produce an LED destroying 750mA when hot.