Today I thought I'd show what's up with my screen. I'm back to using just my main original bucket (that started with pre-grown screen), since the 2nd bucket that I used for the build thread is on loan to the lfs. I'll be posting progress pics of that soon. But for my tank/screen, N and P are zero of course. I check every day unless I forget. The main development has been true green turf, i.e, not green hair or slime. Now, hair and slime are always there (they grow right over everything else), but I started noticing that after regular cleanings there were still some green remaining. I thought I was just rushing and missing it, but it got to be too much green. So on the next cleaning I used the camera, and when cleaning I found for the first time true green turf. I also let it grow more than I normally would, so the pics would show more:
Here is the screen just before cleaning, looking down into the bucket (both sides looked about the same).
Hi-Res:
http://www.radio-media.com/fish/ScreenBeforeCleaning08-27-08.jpg
Here is the screen pulled out (still not cleaned):
Hi-Res:
http://www.radio-media.com/fish/ScreenBeforeCleaningRemoved08-27-08.jpg
Here is the screen after a regular cleaning (scrubbing) with fingernails and toothbrush. Note that tons of green remains:
Hi-Res:
http://www.radio-media.com/fish/ScreenAfterCleaning08-27-08.jpg
Here is the screen after scraping with a razor blade:
Hi-Res:
http://www.radio-media.com/fish/ScreenAfterScraping08-27-08.jpg
Note how most of the green turf is on the top half of the screen, near the lights. The flow is the same; only the light is stronger near the top (the very top is only one inch from the lights). It had been exactly on one month since I'd used a razor before this. It took that long for the real turf to grow (both red/brown and green). Real turf takes so long because it is very tightly packed and strong, with very little water. It looks like the green turf grows a bit faster than the red/brown, however, and is not quite as strong; it grows longer too. However I still could not scrub it off with my fingernails or a toothbrush, no matter how hard I tried. Only the razor could get it off. Took about 5 minutes; not bad for a month of growing.
Anyways, intrigued by this green turf, I went down to the beach with a camera so I could search for what I've been wanting for a while: Pics of how real turf lives. Sure enough I found it on the pylings of the pier at Paradise Cove (just north of Malibu):
Hi-Res:
http://www.radio-media.com/fish/TurfBeach.jpg
Hi-Res:
http://www.radio-media.com/fish/TurfBeachCloseup.jpg
It's exacty what was on my screen. The white specs you see are sand. In order to get the second (closup) pic, I had to pinch the turf very hard and pull it out... like pulling out plant roots; then I held it up for the pic. Note also that it's low tide, which means that the turf holds its color and stays alive for many hours in direct sunlight with no water. Further down the beach I found the same turf on rocks that were 100 feet away from the water.
So, like I said before, real turf is used to living out of the water, and that's why I say that to simulate this (as Aday's machine does) you need some type of on-off-on pulsed flow, and the easiest way I could think to do this was a wavemaker timer (although, as I'll post soon, other folks are coming up with ingenious ways too.)
And again, the importance of light is clearly apparent with this green turf, since it grew no more that 6" away from the lights at the top. And lastly, it does look like some of the red/brown is being replaced by the green, which makes sense since the original red/brown came from IA with their different nutrients and lighting.
