My current scrubber had been working well. Its a 4"x8" screen with dual 100watt CFL bulbs. I dont have any pictures, but recently as of about a week or so, I have cyano red and green growing out of control in the sump area where my scrubber is. The walls are covered in red cyano covered bubbles and the floor has a garden of 4" cyano slime strands. I also have a bright neon colored green, hard to remove slime algae on my screen that is around the edges that I assume is also cyano. The center of the screen is a yellow green normal looking algae. So far this is only in the sump where there is low flow and 18 hours of light. The DT looks great and has super clear water. Levels all read good. Here are some pics from start up to when it had a nice layer growing. Here is what I believe is the issue with my current design. My slot pipe is only 4" long and is getting flow from a direct connect MJ1200 so flow should be plenty. 1. The spillage of light and low flow in my sump has caused the huge red/green cyano outbreak. 2. The CFL bulbs and reflectors are large and bulky, get salt splash, and spotlight. That said, I want to try and limit light spillage and upgrade to LED's. My screen size of 4" wide by 8" tall and the flow from the MaxiJet 1200 seems to be right on, so I dont think I am going to change that. Looking around I ordered this DIY LED kit with 8 660nm LED's and a 600ma driver. 8x3 W LED With Constant Current Driver Kit. DIY item The only thing I m having a hard time deciding on is how to mount the LED's and contain the light. I like the idea of building a black box with clear sides that has black pockets on the clear sides to hold the lights and sit this on some top braces. But I have some questions. 1. how far should the standard 3 watt LED's be from the scrubber screen? 2. I was going to mount the LED's to Aluminum U channel I have laying around. How hot do the LED's get? Can they directly touch the clear acrylic? 3. I am trying to keep things as low noise as possible. Is there a benefit/drawback from having an open bottom box so the screen touches the water vs having a closed bottom box with adjustable drain and emergency over flow?
Open bottom box should be fine, and there are many methods of blocking the light, things like a black still plastic sheet cut to form around the reflectors or even just cutting up a black garbage can with holes for the lights to poke through. But in your first pic, that's an LED PAR type lamp not a CFL so I'm a bit confused, you said it was CFL? U channel may be enough, but they will tend to run a little hot. And no, don't let them touch clear acrylic. I would keep them 3/4" of more off the acrylic, but this is less of a concern with 660nm and more with just about every other bandwidth (like WW, CW, RB, etc) because those are more intense at the same current when compared to 660s
Sorry, the pic is misleading. I started out with a 12 watt par38 grow light on one side and a 100 watt CFL on the other. I ended up switching to both CFL. Am I on the right track? Is it normal to have so much cyano in the sump with scrubbers? its very strange, its only in the center section. There is none in the DT, left return side of the sump, and right skimmer/drain side of the sump. Also, what is the type of bright green slimy algae that attaches firmly on the screen in lumps? Its the same color as green slime cyano but its on the screen which has a lot of flow moving over it in the lower light areas. (around the edges)
Wherever you have light, you will typically grow algae, so yes, this is somewhat expected. But you are on the right track, once the scrubber gets going strong the algae in the sump might start to fade away, adding light blocking of any kind would surely help though Initial growth stages vary, so I wouldn't worry so much about what you are seeing right now, you should eventually progress into a phase where GHA is dominant.
