B.a.d.a.s.s.

Hopefully in this photo, you can see epiphytic algae growing on the green filamentous stuff. Hey presto, a 3D screen;

 

This thing is growing like crazy now. After another 6 hours;

 

Bought an ipad light meter app (not the most accurate probably, I would admit) and measured the light output at screen distance from light source and it's 650ft candles (7000 lux), almost identicle to the LEDS I've been using at the same distance. If we assume the photosaturation constant at 400ft candles, then this screen cannot be light limited, either with LEDS or MH at a distance of 8 inches.

 

Well, it's not died yet. I figure the test will be to see how it grows back after harvest;

 

Cheers Kerry, it does seem to grow rather well at the minute, now for the first of the regrowth test pics;
Harvested;



Seem to be able to let this screen grow 3 weeks between harvest without detachment, perhaps because blue penetrates better or perhaps it's because I've controlled the water depth better, maintaining 3 inches. Either way the growth on the screen is still alive, even with a bit of red turf appearing. First two weeks was 87 watt cheap Chinese grow lights;

 

After some research on light intensity I have concluded that I will not be able to over light this screen. So I've raised the screen to within 3 inches of the light, and raised the sump level to accommodate (it's only a slow flow through sump so if the return pump fails, increase in sump level is only 5mm or so).This Metal Halide is pumping out 13000 lumens at the centre of the screen and as far as I can tell, this is 182uE. This level is probably around the saturation level (although not maximum growth which is 6 times higher).

This pic at 14 days but only one day with higher screen;

 

Cheers Peter. I think this screens ability to cope with 10 ml cubes a day is a start but it could do so much more, if needed. Scrubbing capability should be a function of screen size multiplied by available light (on this screen anyway).

 

A couple of days into a cleaned screen (got rid of the cable ties) and oxygen production is certainly higher than ever before. Oxygen production = photosynthesis = happy bunny;

 

Decided that the pump may be overkill on my screen so I've decided to turn it off and just rely on the very small amounts of flow from my display overflow pipe. This is only a few days with such low flow but going to clean the screen today and see if there is any noticeable difference in growth.