I love these photos! 5 consecutive days of growth on my new L2 scrubber. first photo shows screen with lights set at about 7 o'clock. Photos 2 turned up the lights halfway. Photo 3 about 3/4 turn. Photo's 4 & 5 lights on full! In just FIVE days I was able to turn the lights to max. This is my third week running the scrubber. I am running the lights 16 hours right now. I might go to 18 hours depending on my nitrate levels this weekend. I will post photos of growth after 4th week, hopefully the screen will be completely full of algae.
That's nice growth! You make a good observation here that is worth noting. If you have GHA on the screen and it grows OK when you crank up the light, technically, you can increase the light intensity along with the growth like this. But, you can't force growth to happen by increasing the intensity - meaning, you have to have growth in the first place, excess intensity can cause photosaturation (no growth) If you have a relatively new screen (less than a month old, sometimes less than 2 months old) and you go to harvest and all of the algae comes off, or the majority of it does, you should not put it back into the 100% intensity environment - you should back the intensity down again, probably to the 4-5 o'clock range and monitor to make sure it picks back up again. One of my as-of-yet unrealized concepts with my units is a light-cycle based on the harvest. The driver board has PWM inputs for using a controller. There is a 12V DC output also, so if you have an Arduino you can power it from the driver board. Then you could have a "reset" button that sets the light intensity and ramps it up over the course of a few days. That's just the basic idea, you could also pulse the lights, or pretty much anything else... Reef Angel is PWM out so that is compatible out of the box. Apex and ReefKeeper need an interface board between the controller and the scrubber lights to convert 0-10V to PWM
I like the idea of of a light-cycle based harvest. I have an apex, so I assume all I need is a two channel VDM cable. If I remember correctly the driver board has push to connect wire plugs. See attached photo, I think this is the cable. What interface board would I need?
This one: Aquarium Controller Interface Harness Just the 2-channel version, you can power the harness board off the 12V port on the driver board. Plug the apex wires into #1 input, then PWM #1 out to the driver board. There is only one controller input on the driver board so it dims exactly like the knob does, just electronically. You will want to max the external potentiometer, but leave the SMD pots alone. Those are set to red channels max and violet at 50%. Then those dim in unison relative to the SMD pot setting. So if you have the input dimming signal at 50%, you will get 50% on both red channels and 25% on the violets (which is 50% of 50%). Technically you can adjust the D1 SMD pot (violet channel) to max also. The power supply is sized to handle 3 channels at full 700mA plus the external power load of the harness (or anything else connected to the 12V jack) plus overhead for safety. Plus, it's a Meanwell. You can run it at 100% all day long and you'll never smoke it (well maybe not never...rare...) Technically you can also use the external potentiometer to set a relative maximum, so lets say you temporarily want to reduce the intensity to 80% of what it is across the board, but you don't want to reprogram your Apex. Just turn the potentiometer to 2 or 3 o'clock and that reduces any commanded signal down.
