A few weeks ago, I started digging my pond to be. I hope to have it going by spring. I plan to build a scrubber out of a plastic "55 gal drum" (I've got some food grade ones that have been sitting around for years). I'll mount the spray bar through two holes drilled across the top of the drum. Next is cutting a couple of portholes through the sides to artificially light the screen on both sides. Water drops off the screen into a bed of lava rock and back into the pond. The top comes off easy for screen removal and cleaning. Assuming this is a reasonable thought experiment (it's still too tenuous to be called a "design"), how do I cut and drill the drum? A hole saw drill bit for the pipe mount?? A jigsaw for the portholes??? And lastly, how do I plumb the bottom to seal the round side the the barrel for the exhaust floe? Thanks.
Is the scrubber going to be indoor or outdoor? If outdoor, you're going to need waterproof light fixtures, and if that is the case you might be able to find something that is truly wet-location rated. You should be able to use a jigsaw for cutting just about any hole in the drum, for the drain I would consider the hole saw & uniseal.
The scrubber will be outdoors, under a deck, hence permanent shade. But the outdoor location brings forth more lighting questions. If the lights are on 18 hrs a day, I'll be attracting a tremendous number of flying insects and I worry I might get quite a few bugs decomposing in the sump.
You may or may not need the lights to be on that long, but it depends on many factors such as the bioload, screen size, light size, flow rate, etc. You will just have to gauge that as you go though. What are you going to be putting in the pond? I assume this is freshwater also - that's a bit of a different animal, the algae tends to grow very fine like human hair, and detaches easily under too much weight. This is more of a concern during the maturing stage, and as the screen gets older the algae will hold on a bit better. Going back to my first sentence about photoperiod, with FW scrubbers, history has shown me (not personally, but based on examples and customer feedback) that once the screen is mature you can pretty much run any photoperiod you want. If you seal up the container well enough so that the light doesn't bleed out, you will have fewer bug concerns.
The inhabitants of the pond will be a decent sized slider and whatever he decides isn't worth eating. So I anticipate plenty of bio-load for whatever filtering system(s) I employ. Back to the lighting, ideally I would like to light the scrubber at night as the pond itself will be getting sun, especially before the trees leaf out. I'm in a rural location and the night times bugs are, well it's probably not that much different than night time in Iowa. My plan is cut two portholes in the barrel with grow light spots beaming thru the holes. (I've seen some outdoor type fixtures that I plan to try.) Ideas on how to light seal the contraption would be appreciated. Maybe I should start a new thread here, but I am too lazy.... I have a bunch of equipment that came with a reef tank I bought about 25 yrs ago from some dude who was moving, but the equipment wouldn't work right for me in the undrilled tank. The siphon inflow box had too narrow a water level for operation and smaller living stuff got sucked up all the time. My plan is to use a trickle filter (it's got bioballs and some sort of plastic ribbons) as well. Easiest to build would be for the scrubber outflow into the trickle filter, but the opposite arrangement is possible. I suspect that max algae growth would be putting the trickle filter before the scrubber, but max flow rate over the scrubber might dictate a different placement. Or maybe it doesn't matter? I would appreciate hearing your thoughts. Thanks.
What's a slider? beside a White Castle burger...at least that's what my Dad called them If you get some waterproof lights, you can either figure out a way to mount them inside, or cut holes and poke them through from the outside and figure out a way to seal them around the edges. Not necessarily a water seal, but just an air-seal, to keep the light contained. Should be relatively easy to figure out. It comes back to the screen size, that and feeding/load will dictate how big or how many light fixtures you need. The very common cheapo china light is along these lines: http://www.ebay.com/itm/12W-40W-60W...ower-Plants-LED-Grow-Light-Lamp-/221516793201 And a pair of the 100W ones would light up a big screen (like one you can fit in a 55g drum) pretty well I would think. That, or something like it, is what I would use for a poke-through, but I'm not sure how hot they get and if you would have to isolate them from the plastic drum itself, I'm guessing better safe than sorry. You could also go with the Expressions-LTD strip lights, which are supposedly waterproof, and hang them vertically inside the container http://www.expressions-ltd.com/Algae_Scrubber_LED_Light_p/led-grow-light.htm
A slider is an aquatic turtle. It's perhaps the most common in the US. They have voracious appetites and can be quite the messy eaters. Thanks for the lighting tips. Don't mean to seem greedy, but what's your thoughts/experiences using other filters in addition to the scrubber?
Wow, that looks like an excellent fixture. I see you used the word "supposedly" so I infer you have no direct experience with this light. A
Correct. I sent a message to the guy who sells it to see if I can get more info. When I update the "basics", I plan to incorporate some info about a few stock fixtures that seem to work well
Not greedy at all, I'm here to help anyone with anything really... I don't know a lot about ponds, so my advice would be pretty limited. The standby filtration systems for pond systems seem to be the wet/dry trickle type filters or canister filters with removable media cartridges (corrugated filter), something to keep particulates down. Probably because they are outside and you get a lot of stuff blowing into the water. The wet/dry will be good at removing nitrogen compounds (biological filtration) but that's about it IMO. What you could do, if you wanted to use a wet/dry, is build it into the 55g drum. Have the scrubber take up the upper half, and let it drain onto a drip tray over a large compartment of bioballs. The simplest version of this would be a 5g bucket with a bunch of holes drilled in the bottom (or cut out the bottom, and put in a piece of egg crate) and fill it with bio-balls, then put a filter pad on the top of the drip tray. Drip tray on top could be egg crate also, then just lay the filter pad on that. So each time you clean the scrubber, you change/clean the pad, and leave the bioballs in there. Every so often, take out the bucket of bioballs and give them a quick rinse. You would probably want something pre-filtering the water before it enters the 55g drum filter. This could be a pond pump system with a strainer on the intake, something along these lines http://www.lifegardaquatics.com/product-category/pond-water-garden/ those are pool & spa type pumps, not sure if they are OK for running outside i.e. in the rain, etc. I know that when I was a kid we had a pool and that pump was similar and totally exposed so it was made for running outside, I don't think all of these types of systems are like that.
Now I don't think the bugs will a problem. I can keep the drum's water level where a fish or two living in the barrel can have a feast.
