SantaMonica

Clean every 7 days.

That is before cleaning, correct?

Screen Recomendations I've been doing research on the ultimate screen material. I want it to have all the best characteristics, so if you have some ideas as to what the material should do, or what it should have, let's hear it.

Cleaning a new screen will usually get down to the plastic. But if you sanded/roughed it up enough, the 2nd and 3rd cleanings will leave more behind. just brush your fingers across the screen like this...

Update: Screen Sequence Here is the typical sequence of algae on a new screen: First is a light brown coating, like a slime. After a week of that, you clean it lightly, and the next week you get a darker brown. After you clean that, you'll either get very dark brown/black stuff which stays very hard and thin, or you'll start getting some green hair. If it's the dark stuff, clean it right way (don't wait a week). After a few cleanings of this dark stuff, it too will start turning green. After a month or two, most of the growth will be green hair. If you start getting purple cyano on the screen, it means your light is too weak or too far away. If you start getting a hard yellowish plastic-like coating that covers the algae, it means your flow is too low in that area. If you start getting bald spots near your bulb, it means you are leaving your bulb on 24 hours, when you should be turning it off 6 hours a day. If you start getting round holes in your algae, it means pods are eating through it, because you are not using freshwater in your 7-day cleanings.

Would like to hear what happened. I hope to post the 10g soon.

Glad to hear the the success! Here are some improvements that will make it work even better, if you like... increase the bulb wattage; put a timer on the bulbs to rest them 6 hours each night; make sure you remove the screen and clean in your sink with FW, every 7 days. The reason you don't see copepods is because they are only babies... less than 7 days old. You can see them in the water in your display (as long as you don't have any foam/floss)... they looks like white dust.

Update: Empty Spots On Screen Some people have small spots on the screen, about 1" (25mm) wide, that have no algae; these spots are scattered across the screen (not just near the bulb). These spots are where algae actually WAS growing, but the algae could not hold on, so it let go and went into the water. The reasons the algae could not hold on are: 1. The screen is too smooth (most common problem). No matter what material you use, you should use rough sandpaper to really mess up the surface. If the material is clear (like acrylic; not recommended), you should not be able to see through it at all. If the material is not clear, you should not be able to see a reflection, at all. If the material is a solid sheet, holes should be drilled every 1/4" (6mm)... instead of every inch like many people have tried. With solid sheets, instead of drilling holes, it's better to lay a layer of rug canvas, plasic canvas, shade cloth, or perforated drawer liner, across the surface. You would sand this also. 2. The screen is too thin. Screens should be about 1/4" (6mm) thick. This is thicker than most materials, so you should use two or three pancaked layers of material. This gives the "roots" of the algae more to grab onto. 3. The lights are not being turned off each night (18 hours ON, 6 hours OFF). So the algae grows, but then gets weak because it cannot rest. So it lets go. 4. The flow is too low (the opposite of what you would think). Higher flow delivers more nutrients to the algae (so it can grow strong), and also gives the algae more protection from the light (since the thickness of the water on the screen is more.) 5. The bulbs are actually TOO near, or TOO strong (this is very rare, however). It seems that bulbs that are 60 watt CFL (actual, not equivalent), AND which are 2 inches (5cm) from the screen or less, start to do this. If your flow is strong, then try decreasing the light by either (1) reducing the ON hours, (2) moving the light out to 4", or (3) getting smaller bulbs. But only try one technique at a time.

Update: Pancaked screens Since nobody is currently manufacturing a proper screen for a scrubber, we have to make the best of the materials we can get. Whatever material you use, it has been found that stacking two screens together works better than one. This is when you "pancake" two sheet of screen material together; they can be glued, sewn, or clamped together. This gives the algae much more to grab onto.

Then I'd try to make a ventilation hole on top and bottom. And maybe with a computer fan. I have the same problem, and for now I just leave the cabinet door slight cracked.

Wow, the first circular design! I totally forgot that you can use flexible conduit, since it's already split. Looks like you have most things figured out with the plumbing. And since the screen is one-sided, did you double the screen size? Although I guess you could put lights on the outside too. Also, did you rough-up the screen? Only problem I see is the lighting. The red and blue colors were the right idea, but you were correct that the LED's are not powerful enough. Not even close. You MIGHT get some light brown slime growing after several weeks, but it will never grow any meaningful amount to do any filtering. But the fix is easy: Just replace the LEDs with two or three T5 Gro-Lux (pink) flourescent bulbs. You want to get about 100 watts of bulbs in there, so really, three or four 24W bulbs would be best. Just be sure to put them in a plastic tube like you are using now.

Excerpt from "Feeding The Reef Aquarium", by Ron Shimek http://reefkeeping.com/issues/2003-02/rs/feature/index.php "It will become apparent that many of the problems we have with reef aquaria, such as excess nutrients, excessive growth of undesirable algae, and the inability to keep some animals alive and healthy is simply due to the feeding of inappropriate foods, compounded by feeding in the wrong manner. "Bacteria, in fact, are an important food for most benthic or bottom-dwelling marine animals. This is because bacteria have higher nitrogen to carbon ratios in their cells than do either typical animals, plants or algae. As a consequence, many marine animals are specialized to eat bacteria, either directly out of the water column or indirectly as a frosting on sediment or detritus particles. "One quite good study discussing zooplankton availability and concurrent feeding by planktivorous reef fishes has been published (Hamner, et al., 1988) [...] These researchers examined a reef [and found that] during a 12 hour period [in a section of reef only 3 feet wide, there were] 1,098,000 potential food items, about 70 percent of which are copepods and larvacean tunicates. "A large amount of the zooplankton food that would have impinged upon the reef does make it to the reef, albeit modified into the form of fish feces. This [waste] is rapidly ingested by corals and other benthic animals. "Also, what is apparent is that the fish eat ALL the plankton approaching the reef. NONE of it will reach the reef during the day when the fish are feeding. "All of these fishes [listed in this article] eat large amounts of crustacean prey, particularly copepods. "From this study, it is apparent that these fish are feeding continuously throughout the daylight hours. They are eating small items, but on the average they eat an item of food every three minutes, all day, during a twelve hour day. During that period they eat an average of two grams of food per day. [...] On the average, if you wish your fish to have the same mass of food that they are likely to eat in nature, presuming the data of Hamner et al., 1988, is applicable to other fishes, you should feed each fish in your aquarium that is the average size of a damsel fish, the equivalent of about 70% of a cube of this food per day. Large fishes would get proportionally more. "During the day on a natural reef, it appears that virtually no moderately large zooplankter would reach the coral on the reef's face [because they are eaten by the fish]. Nonetheless, this area would be bathed in a diffuse rain of particulate organic material derived from fish feces [waste], dissolved material and microzooplankton. "All aquarists may significantly control the amount of particulate food in their aquarium. This food will mimic either the zooplankton or the particulate organic material components of coral reef feeding dynamics. For the animals in a system to be healthy, those animals must be fed foods that more-or-less duplicate the qualities of their natural foods, and they must be fed in a more-or-less normal matter. Reef aquarium foods and feeding regimes tend to fail rather spectacularly on both accounts. "The standard reef aquarium is probably fed once about once a day (Shimek, 2002), and the average daily feeding ration weighs 15.39 ± 15.90 grams, or roughly a half of an ounce, wet weight, of food. On a natural reef, this would be enough to provide roughly eight damsel fish with their normal daily allotment of food. Unfortunately, this amount of food all occurs effectively at once (or over a very short period) in an aquarium, whereas on a natural reef it would occur over a 12 hour period. Additionally, aquarium food is a relatively high-protein material. When most reef fish\es encounter planktonic patches of food, they eat voraciously, and material gets passed through their guts in a rapid manner resulting in incomplete digestion. This is precisely what happens to many fish in an aquarium when it is fed. If you watch some of your plankton feeding fishes, such as clown fish or damsels, you will see that shortly after the initiation of feeding they start defecating food at an increased rate. In effect, they are pumping food through their guts. The faster the passage of the food through the gut, the less the fish get from it. Perhaps in nature this doesn't matter, as the food is always coming at them. In the aquarium, this effect could be quite deleterious. "In aquaria, fish that naturally feed consistently on small particulate material throughout the day are being forced to exist on bulk feedings once a day or with less frequency. Under such conditions, the animal is going through continuous cycles of near starvation followed by satiation followed by near starvation. This cyclic feeding simply must have a deleterious effect on the fish. Under such situations one could expect lower than normal growth rates, higher stress, increased susceptibility to disease and possibly problems with nitrogen metabolism. "The amount of food impacting on the [natural] reef over the course of a day is substantial. Over a section of a natural reef about three feet on side, flows a continuous flood of water carrying with it about 2,000,000 food items with an aggregate weight of about two pounds in a 24 hour period. These tiny food items would be like a rain of diffuse nutrition on the reef and reef animals, particularly the fish. "It is apparent that coral reef planktivorous fishes, and this is most of those kept in aquaria, would benefit from changes to the normal aquarium feeding regimen. They should be fed by some sort of continuous feeding apparatus. The food dispensed by such an apparatus should be particulate in nature, and very small. The largest sizes should probably be on the size of a brine shrimp or smaller. Such food need not be specifically formulated to be highly nutritious: Rather it should be of low to moderate nutritional value. If aquarium fish are able to eat more continuously and slowly, they will get much more nutrition out of each food item than they do now. Feeding a low quality food should result in significantly less nutrient accumulation than is now commonly seen in tanks. "In effect, we need to turn our feeding regime on its head. Rather than feeding a small amount of highly nutritious food once a day, we should be feeding a large amount of low nutrient value food frequently. Such a feeding regime as this should reduce significantly the amount of pollution effects in reef aquaria. Additionally, there would not be a daily pulse of nutrients to temporarily overwhelm the biological filter. In turn, there would less potential growth of problem algae and the development of a more balanced and easily controlled assemblage of animals within the tank. [skimmers remove plankton, particulates, and copepods] [scrubbers add copepods, and don't remove plankton or particulates]

Fantastic. And with 7-day cleanings, it will get even better.

Yep. And I built one for a 10g. Will be posting those in the next few months.

Mine is good. Been experimenting on very heavy continuous feeding. Will have a full update soon.

If it's been 20 days, then it's pods. So clean every 7 days now.

Almost certainly pods. How long did it go between cleanings?

Not really. The problem is you are not exporting the algae from the one wall. If you could somehow take that one wall out and clean it once a week, then yes. But since it stays in the system, it undergoes the same problem as a scrubber that is not cleaned weekly: New algae grows over the old algae, shading it, and causing it to die and go back into the water. Now, some displays which are "full" of hair algae will test zero for nitrate and phosphate. But this is because the algae in the display always has "new" area to grow onto. So the new area is fresh growth, which takes up nitrate and phosphate. The algae can continue to spread in your display, and continue to keep N and P zero, until every square inch of rock, sand and glass are covered. Only when it gets this far (which you would not let it), would nutrients start rising in the water.

Update: Yellow rubber algae Many people, including me, get large parts of the screen that turn into a thick yellow growth that feels rubbery. This is caused by flow that was cut off, by algae growing up into the slot. As the slot gets cut off and the flow reduces, the algae that was growing on the screen in that flow now has no flow. And the yellow rubbery algae is what results. It does not appear to hurt anything, but it surely is not effective at filtering, since there is no water flowing over it for it to filter. One solution is to make cross-cuts in the slot. Another is to put a light-shield over the slot. Another is to point the bulbs further down the screen to they don't shine as much on the slot.

No, it's probably the algae that dissolved, leaving pure white rock behind.

Yes red slime goes away just like regular algae.

Update: Displays with lots of Hair Algae It's happened several times now: Someone wants to add a scrubber to their system because they have a display with very thick hair algae on the rocks. They already measure zero nitrate and phosphate, and when they add their scrubber, the scrubber has a very slow start and does not seem to grow much. Of course what is happening is that the hair algae in the display is ALREADY a scrubber, attached to the rocks! It has had plenty of time (months? years?) to establish itself, and most important, it has a gigantic area to attach itself to. So how do you beat it with your newly-built DIY scrubber? You do it with the power of light. All algae operate on the of photosynthesis of light. The stronger the light, the more the algae will pull nitrate and phosphate out of the water, and it will pull it away from any other algae that has less light. This is important to understand: If two areas of a tank are identical, except one has stronger light than the other, the area with the stronger light will grow more algae, and, the area with less light will grow less (or none at all). This is why the top of your rocks grow more algae (it has more light) than the sides do (has less light). So if you already have lots of hair algae in your display, you have to build your scrubber with even more powerful lighting than you normally would, so that the photosynthesis in your scrubber will overpower the photosynthesis of the algae in your display (then, after all the algae is gone in your display, you can reduce the wattage if you want). The bulb wattage to do this is about one CFL watt for every square inch (6.25 square cm) of screen area. Example: Say your screen size is 10" X 10" = 100 square inches; if you did NOT already have a lot of algae in your display, a 23W CFL floodlight on each side of this size screen would be sufficient to keep all nuisance algae away. This would be 2 X 23W = 46 total CFL watts, for 100 square inches of screen. This is about a half watt per square inch. But to beat a large amount of established hair algae in the display, go for maximum power: 1 watt per square inch. This is about twice as much. So, using two of these same bulbs on each side (4 total bulbs) would give you about 92 total watts for 100 square inches, or, almost 1 watt per square inch. This would do it! Note about wattage: We are talking here about real CFL watts, not "equivalent" watts. If the bulb says "23W = 120W", or "23W equivalent to 120W", we are talking about the 23. And if you are using T5HO, such as a 24 inch 24W bulb, you just use the wattage it says. Another trick: Add a lawnmower blenny to the display. He will eat the "scrubber" in the display, so that the scrubber you build gets off to a faster start.

I see now. That T5 was way too far away. I hope your LED's work better. However I think the best result would be two clip-on 23W CFL floodlights, pointed straight down at the screen.

Excerpt from "Waste Extraction, the Invertibrate Way" by Ron Shimek http://reefkeeping.com/issues/2005-08/rs/index.php "The animal poops it out, and from then on the scavengers/detritivores get rid of it." This is, of course, a very concise way of thinking about the elimination of uneaten food from the digestive tract. Unfortunately, it has nothing at all to do with what biologists consider to be waste. Not to put too fine a point on it, but fecal matter is nothing more than uneaten, partially digested and processed food. "Actual waste materials are something else altogether. Strictly speaking, to a biologist, only a couple types of materials are truly waste materials. These are the byproducts of cellular respiration and protein metabolism, which in most animals, are carbon dioxide and ammonia, respectively. [scrubbers remove ammonia and carbon dioxide; skimmers do not]