This is a prototype light base for growing phytoplankton

I've always wanted to grow phytoplankton, but didn't want to do the typical PVC pipe and shop-light setup. And I was looking for something new to design and print. This is printed in PVA, but I'll probably move to PETG for the final prints.

There are 14x3 LEDs (42) running at 12v. It was pulling almost 1 amp, and they were getting too hot. I put in a 5 watt 5 ohm power resister in series, and that dropped the current down to 550ma. Still a little warm, but not baking at least.

In my next version I'm going to try to use some 3w Red/Blue LEDs like these on a heatsink: Red/Blue LEDs

Here are the LEDs that I actually used: Waterproof 5050 plant frowing light red/blue

And these are the power connectors I used:10 Pair DC Jacks

Here is the rendering of the base from Fusion 360:

And some completed pictures:

The neat part of this design is the micro-switch. When the bottle is placed on the acrylic lens, the lights turn on. They turn off again when the weight is removed. It takes about 5 oz (400ml) to turn on the light, so the 1 liter flasks I have will work perfectly.

Thingiverse Files

Here are some growth shots from the first four days:

After 1 day, 200ml of Mercer of Montana phyto in the left flask, 20ml in the right. Each picture taken at about the same time at night, with the phyto base lights off so the green can be seen:

After 2 days:

After 3 days:

After 4 days:

So I can certainly confirm that 6.6 watts of red/blue LEDs (Four red for each blue) can grow Phyto.