SantaMonica

Well replacing RODI/RO/Distilled with tap is not really one of the benefits of a scrubber, especially with a reef. But you are correct, algae does remove a lot of the impurities of tap. If your tank is in a position where you can experiment, then you might give it a try.

As for the wrapping, it's been recently discovered that the screen-wrapped-around-pipe design will clog up and stop working when the algae gets thick. It grows heavily where the screen is wrapped at the top, and blocks further flow from going down the screen. Instead the flow starts going out the ends, completely missing the entire screen, thus killing what algae was previously growing on screen. It affects different screens in varying amounts; the higher the lights are (thus closer to the wrap), the more it clogs. One solution is to use a one-inch light shield along the pipe, to keep light off the top part. Another is to cut holes along the top (but even they will clog eventually). Best solution is to use the screen-in-slot method. Just practice building one a few times. Or get someone else to build it for you.

. Update: The Trick of Dark Brown Algae This has now happened to many people who have new scrubbers. They get early growth, but it's not the green stuff that they see in most pics. Instead it's a dark brown super-thick "coating", or a black "tar", that looks like it was poured on: What you have here is the type of algae that grows when nutrients are extremely high (!). After a few cleanings, when the nutirents come down, the color will lighten up to some balance point where it will stay. The big problem, however, is that people think the screen is not growing, so they leave it in to "grow more" (by not cleaning it). BIG MISTAKE! This type of algae does not grow thick, at all. It never gets more than 1/4" (6mm) or so. And worse, since it's SO DARK, it block all light from reaching the bottom layers, thus causing those layers to die and release nitrate and phosphate back into the water. So the solution is to clean ANY and ALL dark brown/black algae right away, and don't even wait until the end of the week. Basically, if you cannot see your screen, then light is not reaching it and it needs to be cleaned. You'll only have to do this a few times before the nutrients come down and the algae color lightens up. Don't fall for the Dark Brown Algae Trick.

Hi Andrew... great to see your first attempt at a scrubber. Question: Did you wrap the screen around the pipe? Also, can you post more pics, from different views? Please include pics with the lights in position.

Successes of the Day: todj2002 on the SWF site: "since installing scrubber, N and P are still both at zero. i cleaned it again today. not any big deal, but huge progress for me. finally beat the algae after two years of trying. using scrubber with chaeto and RO water now. finally getting somewhere." Marine_Nick on the RP site: "Thought I'd update on my screen. When setting it up I was concerned about light pollution from the sump into the room, and noise from the falling water. as my tank is on an outside wall, I wanted to put the screen outside if possible. I already had an old 18 x 12 x 12 tank, so had it drilled and put a small wier in it, the water is pumped from the sump up and out through the wall to the screen, runs down the screen, through the weir, back through the wall and back into the sump. All of this is in a small shed I made which contains all the lighting etc, my screen is 18 inches tall by 12 inches wide and has a light on either side. Screen has been running now for 4 weeks, and my nitrates have dropped from 30 to 7 and phosphate from 0.25 to 0. In the last 4 weeks, nothing else has changed in my tank other than more fish being introduced, and therefore more food being added, and still the parameters have dropped!! Overall I'm really happy with results so far and hope to see the nitrates drop to zero in the next week or two. Big thanks to Santa Monica for this thread and all the info!" jtrembley on the MD site: "I got frustrated with the skimmer (EuroReef, rated for 80) on my 40 gallon a while back. It was pulling out *lots* of crud, but I was having trouble with detritus building up, and rising P values. Since yanking the skimmer and DIYing (poorly) a rev. 2 scrubber [acrylic box style], phosphates and nuisance algae are down, and the backlog of detritus is slowly being consumed. I'm seeing lots more worms (particularly the small ones that build white, spiraling tubes) and 'pods (amphi- and cope- that is, but not octo-). Here's the funny thing: at the 3 year stage of my 40, I started getting lots of nuisance algae, despite having one of the hands-down best skimmers for small tanks, an MCE600, on it. Thinking that I was doing something wrong, I put an MC-80 on it. After another year, I started getting more and more detritus building up in the display, despite having a *lot* (over 2k GPH) of flow. And then I noticed something else: I no longer had many fan and bristle worms, amphipods, or copepods left in the sytem, either. So...I started swapping out my old LR for new, to replenish the critters. And I tried Fauna Marin and vodka dosing. But the critters weren't really spreading, and the nuisance algae was getting worse, and my P was rising despite water changes. So, I thought about it, poked around, and looked at Eric Borneman's study of *fresh* skimmate (i.e., not stuff that was left in the cup to rot). And I realized something: having a high quality skimmer on the tank was probably stripping the tank of big chunks of its potential cleanup crew. So I took off the skimmer, and put in a turf screen to cover the water's surface in what used to be the skimmer's chamber in my sump. Low and behold: I'm feeding more; I'm once again seeing fresh worm tracks in my sand bed; the copepods are back; the nuisance algae is dying off; P is undetectable by hobby kits; and the detritus is slowly clearing up. And I'm not doing as many water changes. I checked pH this morning, it was 8.2, before the lights are on. I'm honestly not seeing the down side. So yeah, removing the skimmer and putting in a $5 turf scrubber fixed my tank of "old tank syndrome". Just for giggles, I just tested my N (0.2 or 0.5 Salifert) and P (0.05 Hanna photometer). No visible HA, turfs, or cyano in the display, and I can (easily) feed 2X cubes of Hikari mysis, some dulse, and 2 scoops' worth of Reef Chili daily (again, in a 40). And I haven't done a water change in a month. I'm honestly not seeing a downside to scrubbers at this point."

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Nice construction Iceman. The rug option kinda reminds me of a racecar... high performance but constant maintenance. That fluorescent light cover is going to be a bit smooth and slippery, and since it has no holes, there might be the problem of algae letting go during cleaning (or even during growing, if it gets thick enough), thus giving you completely blank areas. But as least it's not fragile or temporary

Update Of The Day: Waste is Food: Reef tank owners sometime get into the frame of mind of "food is food, and waste is waste". Thus they put food into the tank, and they remove waste from the tank (skimming, siphoning, waterchanges.) But actually, both food and waste are Organic, and thus are both "food" (food for something, somewhere). Corals and inverts may not directly eat the big krill that you feed your fish, but they do eat the waste from those fish. Further info: http://www.reefkeeping.com/issues/2002-07/eb/index.php

Yes evaporation will increase, unless you enclose it with acrylic or plastic.

Yep. Ammonia (ammonium) is the most favorite food of algae. But because ammonia get used up so quickly by bacteria in the rocks, algae then turns to Nitrite, then Nitrate, for its nitrogen

Yes, the balls and wool need to go. They only add nitrate. If you have live rock, then you should be ok while the scrubber starts growing. If not, use a polyfiler or carbon for the first couple weeks to remove ammonia, until the scrubber is going. The scrubber will remove ammonia too, after that.

Use a pump feed:

How about this for an updated pic:

My water tests today, all Salifert: N03: 0 (clear) P04: 0 (clear) Si: 0 (clear) Ca: 490 Alk: 9.3 Mg: 1500 pH: 8.4

Thanks. Ca / Alk is constant, by dripping kalk in the top-off (about one drop per second).

90gal reef (algae scrubber system). Scrubber has been the only filter (besides LR, of course) for six months: http://radio-media.com/fish/Tank.htm

For the new year I finally got a camera, learned how to use it, and took some pics. They are linked below, and will be updated as new pics/vids are taken.

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Last Results of 2008: dave3441 on the UR site: "an update for you, been running scrubber since day 1, 19th nov 08 [7 weeks] and tank cycled very quickly 10 days!, although i did have some seeded tonga rock which i kept live bout 15 kgs, the rest was out of water for 36 hours so would have died off. started adding fish at 5 days just 3 chromis to get things fired up then added more fish and corals at 3 weeks still no sign of any additional spikes. its been about 6 weeks now and i have had the very faintest of blooms, just a dusting on glass. cant believe how good this cycle has been compared with first tank set up in 2002. scrubber has been cleaned weekly, to be honest i am cleaning both sides every week as it gets so clogged up . starting to see some more stable green algee now, and this does not come off like the brown/red/black slime does. i just use a george forman plastic spatula and run it down both sides of screen. i would say i get about 1/2 normal size tea cup off screen each time. i gotta say i think this is a very good system, as the algee is definatly growing on the scrubber rather than all over the tank. i have never seen a new tank without the dreaded algee bloom occuring before. i must add i am skimming, although just with a small mc500 deltec which needs emptying approx every 3 days or so. just did battery of tests today approx 7 weeks running now: sal 1.024, temp 27.5, phosphate absolutly zero crystal clear reading not even hint of blue."

One of the advantages of algae is that it grows pods. You don't want to trap the pods and remove them. Anyway, anything that can float and get into your return is food for somebody.

I would not do a cotton filter. First, nothing should fall off the screen (it grows and attaches to the screen), and second, any thing (food, algae, waste) that does float around, you actually do want going into your tank so the corals and fish can eat it, instead of it rotting in the cotton and only releasing nitrates.

Scrubbers are different from a fuge in so many ways: o With a scrubber, there is very little water standing in the way of the light. Also, the light is (or should be) very close to the scrubber... 4 inches (10cm) or less. The power of light varies with the square of the distance, so going from 8" to 4" actually gives you 4X the power, not 2X. And the nutrient removal power of algae and macro is proportional to the power of the light, because it's the photosynthesis that is doing the processing. o Rapid flow across the algae give more delivery of nutrients, compared to the slow moving water in a fuge. o The turbulence of water moving over the sections of algae help remove the boundary layer of water around the algae. This boundary layer slows the transfer of metabolites in and out of the algae. There is no turbulence in a fuge (if there were, you'd have bubbles). o Pulsed Flow: The option of being able to pulse the flow on/off/on (and use a fan) REALLY helps get rid of the boundary layer of water, and also helps kill the slime that tends to cover up real turf (although green hair and brown slime still do lots of filtering). This is how turf algae grows on the beach, with wind and waves. o Surface Area: When you clean/scrape a scrubber screen, the surface area is not reduced like it is when you harvest macros. o Traps no waste/food like a refugium or DSB does; waste/food flows right past the screen. o Does not release strands into display, like chaeto. o Does not go sexual, like caulerpa can. o Is 1/10 to 1/4 the physical size, for the same processing power. o Weighs nothing (holds no water), so it can be placed on regular furniture. o Cools the water. And if a fan is used, it REALLY cools the water. o Does not ever produce hydrogen sulfide (rotten eggs), like DSBs or denitrators can. o Can be set on top of the tank, so pods drain right into tank. o Is free (you build it). o Is portable. o Can run two or three, for backup or extra filtering, in the same space as one fuge. o Will oxygenate the tank if main return pump goes out (if the scrubber drains into the display.)

Good readings, yes. Overflow: That was what I meant in point #4.

Madeley on the scrubber site has come up with a great plan for an in-sump dual-screen scrubber, that could either be manufactured from plastic, or (if you simplify it) made out of acrylic. So for you technically adept folks, here's his drawing, with my arrows and words added: His drawing is similar to Dohn's on the MASA site: http://www.radio-media.com/fish/UserDohnOnMASA-2.jpg ...but simpler (Dohn's I believe was for HOB, so it's understandably more complex). Operation: Madeley has it so it can be placed in a sump front-to-back (sump being sideways), and it will set on the rim; lights in the middle, screens on both sides through the slots in the horizontal water tray, and water fed in from the hole on the end which would thus be positioned at the back or front of the sump. If it's for a sump 12" front-to-back, then the lower section is probably 11" across, which makes the screen about 10" across. So if the screen is 10" tall, then it's 100 square inches, and lit on one side, which is good for a 50 gal tank per screen, or 100 gal tank total. Each 10" wide screen needs 10 X 35 = 350 gph flow, for a total of 700 gph. Lighting could either be two CFL's hung down the middle, or some type of two-sided T5HO (just think how powerful a row of ten 12" T5's would be. This could be an optional feature.) To mold/manufacture out of plastic, here's what I'd change: 1. Water input-hole: Many sumps I've seen won't have room to route a tube/pipe along the back side of their sumps (in order to connect to that hole), and they'd prefer to not route it in from the front. I'd suggest a side or top connection. 2. The incoming 700 gph water, the way is is laid out, is going to be too strong when it hits that center piece. I'd use two separate holes, and let the user divide the water himself with a "Y" before the input. Also, if you make the two water pathways totally isolated, and if the user puts a valve on each water input, then he can keep the pump running on one screen while he turns off and cleans the other. This is a safety factor because some people forget to turn their pumps back on, and/or, they are feeding the scrubber from the overflow. Also, there would be a perceived advantage because "it never stops filtering, even when I'm cleaning it". 3. Screen slots: If the screen inserts through the water tray from the top, then how do you get it out when it's full? You can't pull it up through the slot when it's full. And if the screen inserts from the bottom, how do you push it up and get it through the slot when the screen is flexible?. What you could do is make the water tray removeable, so it just sets down in there. This way, the tray would lift up and bring the screen with it (would also make cleaning, and manufacturing, easier.) And, you'd want the tray to be in two pieces so you can remove one without needing to remove the other. This would work great with isolated water pathways. 4. Overflowing tray: If something real or imaginary blocks the water from going down the slot, the user needs to know that the water will simply overflow into the sump. This is easily done by lowering the outer walls a half inch or so, in the middle section, so water would spill over the edge. 5. Top heavy: With water in the top tray, and two hoses connected, and lights attached, the cener of gravity is going to be very high, and the unit could tip over. While you could fix this by making the unit sit lower into the sump, this would reduce screen area since more of the screen would be under water. A solution might be to attach weights (rock?) to the bottom. 6. Adjustable height: Due to the top-heavy problem, and the unknown height of water in the user's sump, and also due to manufacturing difficulties, it might be easier to eliminate the ledge (that sits on the sump's rim) entirely, and replace it with an adjustable "lip" or "tab". This adjustable piece would be on both ends, and could be moved up or down so that the screen's bottom could be positioned just at the water's surface. If top-heavy, the unit could be lowered (albeit putting the screen into the water.) An alternate solution to the height issue is to have no lip at all (permanent or adjustable), and instead use some type of legs that go down to the bottom of the sump. This would make the top part of the unit smaller (does not need to set on sump rim), but would not reduce the lighting or screen areas. For balance in top-heavy situations, the legs could be weighted (they could be weights themselves), or they could extend out at an angle like a tripod. To have it built from acrylic instead (by hand), here's what I'd change: The above points still apply (water input on top or side, dual inputs, separate water pathways, removeable water trays, lowered-wall to handle overflow). The issue with acrylic is to use as many long straight pieces as possible, and to avoid any internal cross sections. This pretty much eliminates the lip that would sit on the sump's rim, so something would have to hold the unit up; either an adjustable lip on the sides, or legs on the bottom. An easy solution might be to just extend the outer sheets of acrylic (the ones parallel to the screen) all the way to the bottom, and just have slots in them (like vertical window blinds) for water to get through. If made for anyone other than yourself (in which case you would not know the height needed), the user could just cut off the excess acrylic in order to set the height properly. The acrylic design is very simple; just four vertical acrylic sheets (same size), with two end pieces, a drop-in water tray on both sides, and a water hole on both sides. .

Update Of The Day: Cleanings/Scrapings Cleanings are when you take the screen to the sink and run tap water over it as you use your fingers (not fingernails) to remove the loose stuff and wash it off. It is done everyweek, no matter what, even if you think your screen needs to "grow more first". On brand new screens, this stuff is usually a light brown slime, but it can be green slime, green hair, or even black tar-looking stuff. It's important, especially on the first cleaning, to leave some algae on the screen so it can grow back easily. It's also important to only clean ONE side per week (or one-half, if it's a one-sided screen). Cleaning it under running tap water kills the pods that will start to eat the algae (don't worry, there will be thousands more the next day). Scrapings are sometimes needed later on, after your screen has grown a few months. You'll know if scrapings are needed: You'll try using your fingers, or even fingernails, but nothing will come off. Scraping is only needed every month or so, and of course on ONE side only (or one-half, if it's a one-sided screen). I use a razor blade to scrape, but any straight sharp metal object will work. Go back and forth with the scraper until the algae is removed all the way down to the screen. You shouldn't have to worry about leaving algae on the screen; this type of algae is tough enough that there will surely be some left. You may never need to scrape, however, which is fine. But even if you do need to scrape monthly, you'll still need to clean weekly. Here is a video showing a cleaning and a scraping: YouTube: Hi-res: Part 1: http://www.radio-media.com/fish/Scraping1.mpg Part 2: http://www.radio-media.com/fish/Scraping2.mpg Part 2: http://www.radio-media.com/fish/Scraping3.mpg Part 3: http://www.radio-media.com/fish/Scraping4.mpg