Part 3 of 3
Pump feeds: Since with a pump you have control over the flow, start with the size screen you can fit into your space. If the screen will go into your sump, then measure how wide that screen will be. If the screen will go into a bucket, then measure how wide that screen will be. Take the width you get, and multiply by 35 to get the gph you need. For example if you can fit a 10 inch wide screen into your sump or bucket, then multiply 10 by 35 to get 350 gph. Thus your pump needs to deliver 350 gph to the screen.
You can construct your setup using any method you like. The only difficult part is the "waterfall pipe", which must have a slot cut lengthwise into it where the screen goes into it. Don't cut the slot too wide; just start with 1/8" (3mm), and you can increase it later if you need to, based on the flow you get. I used a Dremel moto-tool with a "cut off wheel":
Now install the pipe onto the screen/bucket by tilting the pipe and starting at one side, then lowering the pipe over the rest. You may have to wiggle the screen in some places to get it to fit in:
Lighting: This is the most important aspect of the whole thing. You must, must, have strong lighting. I'll list again the bulb I listed above:
23 Watt R40 Compact Fluorescent Flood 5100K Full Spectrum CFL
... This the MINIMUM wattage you should have on BOTH sides of your screen. You can get even higher power CFL bulbs, or use multiple bulbs per side, for screens larger than 12 X 12 inches, or for tanks with higher waste loads. The higher the power of the lighting on the screen, the more nitrate and phosphate will be pulled out of the tank, and the faster it will happen. You cannot have too much light. When some folks report back that their algae scrubber is not growing algae or working well, the problem is ALWAYS that they used weak lights, or the lights were more than 4" away. Every single time.
Operation:
Regardless of which version you build, the startup process is the same. First, clean the screen with running tap water (no soap) while scrubbing it with something abrasive. Then dry it off and sand it with sandpaper on both sides. Then get some algae (any type) from your system and rub it HARD into the screen on both sides, as deep and as hard as you can. Then run tap water over the screen to remove the loose algae pieces; you won't see the remaining spores that stick to the screen... they are too small, but they are there.
Put a timer on the light, for 18 hours ON, and 6 hours OFF. You will see absolutely nothing grow on the screen for the first two days. But on day 3 you'll start seeing some light brown growth, and by day 5 most of the screen should have a light brown coating. If this level of growth does not happen on your screen, your lighting is not strong enough (you used a weaker bulb), or it's not close enough to the screen (needs to be no more than 4" from the middle of the screen). Increase the bulb power, or move it closer.
When the screen looks something like this:
...then you want to give it it's first cleaning, on ONE SIDE only. Take the screen to the sink, run tap water on it, and just push the algae off with your fingers (not fingernails):
Wait a week, and clean the other side, gently. Wait another week and clean the first side again, etc. After a while you'll have to press harder to get the tougher algae off, and after a few months you'll probably need to scrape it with something, and it may eventually get so strong that you'll need a razor blade to scrape it off. But for now, be gentle; you always want some algae to remain on the screen when you are done. NEVER clean it off completely. Algae has to remain on the screen to do the filtering.
Don't forget to test your Nitrate and Phosphate before you start your filter, and each day after. I use Salifert:
Salifert Test Kits
Post your pics of how you build it, the growth day by day, and your nitrate and phosphate readings, so we can all see how you are doing! There is a lot of info that I did not include here (in order to keep this short), and I've been asked every possible question there is. So if you have an unusual situation, or you think you have thought of something "new", then post it :)
