(UAS) DIY Freshwater Up-flow Algae Scrubber #algaescrubber
My Current Cichlid Tank
What is an Algae Scrubber?
For a basic answer, my research has led me personally to discover that an algae scrubber is an aquarium filter that works on both freshwater and saltwater aquariums and it works in nano tanks as well as large aquariums! It utilizes light, water, oxygen, and tank nutrients for it to work which in turn allows algae to grow in a small area within your tank, above your tank, or inside a sump below your tank, and it does so in a controlled manner. Now, I didn't attend the York Academy of Sciences, or any other school that goes into depth of what happens on a chemical level. All I know is it works. The algae absorbs any undesirable nutrients in the water, it helps to keep nitrates, nitrites and p04 (phosphates) to near or at zero, and it also keeps other competeing algae from growing in other areas of your aquarium, dt or display tank, keeping it looking clean and healthy. Because trust me algae in aquariums, such as brown algae and hair algae, are a nuisance and they are unsightly. Oftentimes, this type of tank filtration system, an algae turf scrubber, is all that is needed to run an aquarium. However, the more that is learned and as more experiments are carried out, things may slightly change. I will explain more later!
Waterfall Algae Scrubbers
Waterfall Algae Scrubber
There are a numerous types of algae scrubbers used by individuals, but the one that is extremely popular and works real well is a waterfall scrubber. This type of algae turf scrubber (ATS), takes water from the aquarium and flows it downward over a rigid screen and back into the tank. If you have adequate intense lighting and air, in time, algae will begin to grow on the screen. With the correct amount of water flow and nutrients, it doesn't take long for this to happen and when it does weekly cleaning of the screen is necessary to keep the process going.
Up-flow Algae Scrubber
Up-flow Algae Scrubber
Another type of scrubber that has caught a lot of attention lately is an up-flow algae scrubber (UAS). This scrubber is very similar to a waterfall type except this time the rigid screen is immersed in the water with the same high intensity lights as the waterfall design. But instead of water flowing over the screen, air bubbles are forced to flow up from the bottom of the screen. The air bubbles envelope the screen with nutrients that you want removed from the water and in time algae will begin to attach itself to the screen, absorbing those undesirable chemicals as it grows. Kinda cool, don't you think! It ought to because it is very similar to what takes place in the oceans, lakes, rivers, and streams. You can't go wrong mimicking mother nature!
Other Algae Scrubber Designs
- CDMills Designs: A New Unique Algae Scrubber Design
We have seen horizontal scrubbers, waterfall scrubbers, and upflow scrubbers. My new design is an in-flow scrubber that is meant to go under the water in a sump with the light in the middle for 360 degree coverage.
My DIY Freshwater Algae Scrubber Project and Ongoing Experiment
Both the waterfall and UAS algae scrubber filters are extremely intriguing to me. And I may end up using a version of both when I build my new tank. But for now, I have a 29-gallon freshwater Cichlid tank that I want to try the UAS filter on. If anyone else is interested in building a UAS diy algae scrubber, you can check out the forum over at http://algaescrubber.net/forum and click on the Upflow Algae Scrubber(UAS) link, to learn how to properly size your screen, what type of bubble flow rate you will need, and what kind and how much lighting is necessary to get your filter up and thriving. A couple of guys on that sight are algae scrubber wizards. Check out the Santa Monica algae scrubber guru and his algae scrubber designs.
My Step-by-Step Freshwater Upflow Algae Scrubber Build
The Screen Size
OK, back to my current do-it-yourself project. (You can easily see my build by viewing the picture slideshow) My screen size is 3"x4" (12 square inches) which is roughly based on my feeding of 1 cube of food daily. The type of screen size guideline that is currently being used is this: screen size should be based on how much you are feeding your tank. But, I would recommend that you keep yourself updated on this because things change, and I say that because it can happen.
***I will also be providing updates at the end of this hub on a regular basis to show the progress of growth on my upflow algae scrubber as well as any changes and upgrades I make***
Sidethought: I have a theory about this guideline, and it is only a theory and it would only apply to freshwater tanks (it could apply also to a fish only saltwater tank, I suppose). My thinking is, the size of the screen should be based on the average size of your fish (adult size). For example, I have 6 mbuna cichlids and one catfish. I have had them for over a year and their average length has grown to 2-inches. So if you take the average size times the amount of fish of have, you will get your average screen size in inches. Thus, in my example, you would have to have a screen that would be 14 square inches, which would account for a little more growth and overfeeding. I don't know, it's just a theory but it ends up close to the current recommended screen size guideline based on feeding. But as it is, I stuck with the current guidelines for my build. Maybe someone else would like to experiment more with my theory. Say for instance you have 42-inches of fish in your tank. You would need a 42-inch square screen (7"x6"). Any thoughts? Again, it's just a theory!!
The Screen Material
- The first thing I did is I went to my local all-in-one store (Wal-Mart) and went to the sewing/craft department and found that they sell a 6-pack of Craft Designer screen. I don't remember what I paid for it but it was extremely cheap and I have enough to build lots of scrubbers!
- The 2nd thing I did was cut my screen. I cut the screen 3-inches wide by 5-inches. I cut it an inch longer because an inch of the screen is going to fit down inside a 1-inch piece of PVC. You will see this later on in the build.
- The 3rd thing I did was got out my 2-inch hole saw and removed the drill bit. I used the hole saw blade to rough up the screen material on both sides. This tool works like a charm because of the saw blade teeth. It really cuts into the plastic screen material and this is important because you want the screen to be extremely course so algae will attach itself easily to it. Rough it up good!!! (click on thumbnails to see full size)
- The reason this is so important is you want the algae to attach itself to the screen. If you leave the algae screen smooth it's a good possibility that the algae will somewhat stick on, but it will probably slide off when it gets to full maturity. You don't want that to happen. So this point can't be stressed enough! Rough up your screen, rough up your screen, rough up your screen!
The Algae Scrubber Container
I'm not real good at building stuff out of acrylic (yet) and I wanted to keep this build as cheap as possible so I searched around for a suitable container that could house my algae screen. I wanted it big enough so that if I wanted to expand the screen size I could but I didn't want it so big that it would take up a lot of room in my aquarium. I happened to find a lock top airtight container that was 36 oz. The dimensions of the box is 8"x5.75"x2".
I was also looking for a container that had a top that was slightly inset so I could install suction cups on it so it would end up fitting tightly against the glass inside my tank. The container I found was perfect! I got it at Bed, Bath, and Beyond for $4.99.
The Algae Screen Holder
- I don't know what else to call it so I will just call it the 'screen holder'. I made mine out of 3/4" PVC pipe and 3/4" end caps. On one side of the PVC I cut a groove just wide enough to fit the width of my screen. It is approximately 3 1/4" wide. I made the groove twice the size of the screen thickness. The reason I did this is because I wanted the screen to be able to move forward and backward in the water. Another words I wanted it to sway back and forth, much like it would if it was floating in the ocean. I didn't have a table saw to cut the groove so I clamped it between 2 pieces of wood, a line was drawn down the middle, and then I used a 3/16" drill bit with a point on the tip to drill holes down the line. I kept these holes very close and was able to do it because the bit had the pointed tip (and that was the secret, because I could push down hard and set the bit right on the line without it slipping off the PVC). It took some time but I think it turned out OK. When I was done drilling I used a file to smooth out the sides of the groove.
- After that, I turned the PVC pipe over and made another groove on the opposite side. This is where the water flows up through the holder and then on up through the screen. You could always just put 4 or 5 quarter inch holes instead. That would make it a lot easier, LOL! Lesson learned!
- Next I drilled 2 small holes from the front of the holder to the back. These small holes hold 2 small zip ties that just slip in but do not get attached. This holds the screen in nicely and it allows me to remove the screen quickly and easily. With a pair of scissors I snipped out 2 small areas of the algae screen so that the zip ties will go through easily. Plus, this will allow up and down play in the screens movement. So now it will not only move forward and backward, it will also bob up and down. (Remember to use very small zip ties, the smallest you can find).
- If you want, you can loop the zip ties under the PVC and zip them, but this would be a headache each time you have to clean the screen. You would have to cut the zips and then replace them with new ones every time. Too much work! Just keep them full length and push them through. They will stay put.
- For my next step I wanted to find a way to mount the algae screen holder to my scrubber container. What I decided to do was to find 2 small pieces of PVC or plastic pipe that I could insert into the bottom of the 2 PVC end caps, pointing down.
- I then dry fitted the holder into the container and marked on the bottom of the container (which actually is the side of the container) where the 2 pipes touch it. I drilled out 2 holes in the container and then pushed the 2 pipes into the holes. What I ended up using for the pipes was a white plastic BIC pen. I pulled out the pen part and cut two 1-inch pieces of the round white plastic. Along with 2 other holes that I drilled in the bottom of the scrubber, these serve as the water inlets to the scrubber from the aquarium.
- In addition, I also painted the screen holder black with Krylon spray paint made especially for plastic.
- Then I drilled a number of air holes in the top of the scrubber.
The Algae Scrubber Face Plate
- I put the lid back onto the container, which will serve as the face plate. I cut out a rectangle the exact dimensions as the scrubber screen. I plan on spray painting the lid black so that light will only go through the rectangle opening, so it will shine directly on the algae scrubber screen.
- Next I mounted 4 suction cups to the face plate (lid). From the pictures you can see that the suction cups are just sitting on the top. Once I drilled the holes for them, they sunk down nearly a 1/4". I then stuck it against the tank glass to see how good it fit. It fit perfect!
- Others that have built up-flow algae scrubbers have also been using magnets to hold their scrubbers up. I chose to go with suction cups because it was easier for me and I don't have to worry about having to seal magnets so they don't rust in the water. Of course, this is a personal preference and if you are building one you can use magnets if you want.
Air Bubbler for the Scrubber
- The algae screen that is mounted in the PVC pipe holder goes all the way to the bottom of the holder. So I took off the PVC 3/4" end caps. When you look down through the pipe from the ends you see that the screen splits the PVC in 2. I installed an air hose to go down one side of the PVC pipe and it then turns and goes back down the other side of the pipe. So another words, there is an air hose in the front of the algae screen and one in the back of the screen. On the end where the hose turns I pinched the hose and put on a small black zip tie to totally clamp the end shut.
- I then pulled the 2 pieces of hose from the one end tight against the screen and made a mark where the 2 hoses reach the other side of the screen.
- I then removed the hose and took a needle and punctured hundreds and hundreds of holes into both hoses between the zip tie and the mark I made. Believe it or not, this did not take long. I made sure to puncture holes everywhere, on the top, sides, and bottom of the hoses.
- I have 2 Whisper 40 air pumps that I have running to the algae screen holder. One for each hose (but really it is just one hose that is clamped on one end). Both air pumps have check valves on them and 2-way plastic control valves so I can control how much air is going into each hose.
- I then put the hose back in the pipe, fit the screen between them, put the far end cap on and then drilled 2 holes in the other end cap to allow the hose to come through.
- I then drilled 2 holes in the side of the scrubber to allow the air hoses to come out.
Painting the Algae Scrubber
- I then took the up-flow algae scrubber apart and spray painted the outside of the container black. I used Krylon black paint and clear-coat for Plastic that I purchased at Wal-Mart. This is great paint and many have used it in their aquariums with success. I'm hoping to join that group. It took a total of 3 coats. 2 coats of black and one coat of clear. I allowed the pieces to dry and bond for 2 days. I then washed the pieces in the kitchen sink to test the bond and to remove any overspray.
- I did not spray paint the inside of the container. I did this for 2 reasons: (1)By leaving the inside unpainted it keeps the sides smooth so algae finds it hard to attach to the walls and sides and (2)this scrubber can be removed from the tank quickly to be cleaned. You pop the 4 locks the box drops into your hand. You then can take the box to the kitchen to be cleaned. You can remove the algae screen holder and then the screen pops off by pulling out the loosely installed zip ties. Once everything is out (which takes less than 20 seconds or so), you can clean the entire inside of the scrubber container with a scrub pad if necessary, and because there is no paint it should clean up quickly. I tried to keep things simple when it comes to maintenance of this filter.
Additional UAS Information
- The holes in the bottom of the up-flow algae scrubber allow water to come into the container which is being pulled up by the air bubbles. The air bubbles wiggle up the screen and vent out through the holes mounted in the top of scrubber. Excess water gets pushed out the holes that I drilled into each side of the scrubber. Hopefully that made sense!
- Lighting comes from outside the aquarium. The light shines on only one side of the scrubber. I made a light using PVC: a 3-inch to 2-inch reducer pipe, a 2-inch rounded cap, and a small section of 2-inch PVC pipe to link them together. Many 1/4" holes are drilled to allow for air flow. I installed a rubber socket from Home Depot into the end of the PVC cap. I am using 1 ecosmart 14W flood cfl light bulb.
I've been noticing that a number of people that are starting to use an UAS filter in their tanks are beginning to notice at times that their nitrate and phosphate levels are beginning to rise and sometimes algae starts to grow a little bit in the display tank again. I think this is due to photorespiration. Algae grows when a number of things happen. First off, there must be enough light and CO2 (carbon dioxide) present in the water. Without these 2 things plants can't function correctly. Then of course the algae needs fertilizer to feed on which comes by means of toxic waste from fish and other creatures in the tank for example. What is unique about algae is it can grow in somewhat lower lighting conditions if there is an abundance of CO2 in the water and it can grow with high amount of lighting intensity with somewhat low CO2 levels. But if CO2 drops to zero, then the algae converts over to using oxygen for photosynthesis instead of CO2. This done for survival of the algae but it also creates a toxic situation within the plant that can cause the algae to release ammonia as a by-product. When ammonia is released into an aquarium and the levels become high then nitrites and nitrates rise to counter it. This may be what is happening in some systems. Solutions? Not real sure. But I'm going to continue to run my Aqueon QuietFlow 50 power filter which has a bio-holster to remove toxic ammonia and nitrites and a diffuser grid to help remove additional toxins just in case there is a spike in ammonia. Additionally, I'm going to purchase a generic ammonia alert monitor to hang in my tank to see if the levels rise. If they do, then that could mean I have depleted all my CO2 in the tank and may need to cut back the light period for the algae or consider adding a CO2 injector to keep levels up when the light is on. Let me know what you think!
Up-Flow Algae Scrubber Updates (8/13/12)
I will post pics and text when I do my regular cleanings of the filter screen. Today is August 13th, 2012 and I just installed my scrubber yesterday so there is no sense in posting any pics this soon. I will let the scrubber run for 7-10 days and check on the progress. I may have to go longer depending on algae growth. I have seeded my screen with algae that I rubbed on it from a generic scrubber that I had running on some old tank water that sat outside for a few days. It had quite a bit of hair algae growing on it so I hope it will transfer nicely to this screen. Later.
Up-Flow Algae Scrubber Update (8/14/12)
Up-Flow Algae Scrubber Update (8/15/12)
Added a Diffuser 8/16/12
Today I added a diffuser to my light. I think that the light is a little to close to the screen so I'm hoping that by adding a light diffuser it will disperse the light a little more evenly on it.
Also, I installed a piece of rectangle acrylic onto the faceplate where I had cutout the top to let the light shine into the algae scrubber. Even though the scrubber is relatively pushed flat against the aquarium glass with the suction cups, I believe that by adding the acrylic piece it will seal the scrubber better. I'm hoping this will allow more water to be pulled up through the scrubber from the bottom more efficiently and up and over the screen. Just a minor modification.
Up-Flow Algae Scrubber Update (8/16/12)
(8/17/12) Algae Scrubber Light and Hoses Update
Before I built this uas (upflow algae scrubber), I had built one out of a red tinted plastic box. The light intensity bled through the sides of the thin walled box so much that it gave off a tremendous pink glow. In fact, at night, it made the whole room shine with pink. That is why I decided to change the algae scrubber box to one that I could paint black.
But what was interesting about that box is green hair algae grew really good and fast and I'm wondering if that pink hue/tint was the reason. So as an experiment, I have added a piece of that red box, about the size of a Quarter to the center of my diffuser to see if it would cast a small pinkish tint onto the screen. I will monitor for a few days to see if makes any difference. I'm doing this because my screen is doing OK for now, but instead of green hair algae all I'm getting is light brown sludge. And I seeded the screen with the algae from the other screen so It should be growing or starting to grow like it did before. Time will tell.
I made some modifications with the air hoses too. I am only running one air hose in the screen holder now. It is producing plenty of bubbles for the screen. The other air hose is being vented into a hole on the bottom of the scrubber causing it to pull in more water. The water flowing in now is pushing against the back of the screen which is keeping the bubbles, that are coming up from the holder, tighter against the screen.
Sidethought: I think a big reason why some are not having as much success with a uas verses a waterfall scrubber is the water turn overrate. I think it needs more flow for it to work correctly. The waterfall designs are run on pumps that turn the entire tank water over the screen many times per hour in some cases. But with air being the only thing that moves the flow with an upflow algae scrubber it limits it. I see that some are having tremendous growth but their P is rising as well as nitrites. And some are starting to get algae growth in the display tank again as well. This could mean that some of the water is not getting an opportunity, or enough opportunities, to run through the scrubber. So some of the water is starting to suffer, especially if this is their only means of filtration. It will be interesting to see if what I have done makes a difference and I might try to think of a way to get a small pump to push more water through as well. I will give this new approach some time first.
I have also figured out my lighting schedule. I keep the algae scrubber light on for 18 hours and off for 6 hours. It is turned on at 4:30a.m. and is shut off at 10:30p.m. I will be adding a timer to do this automatically in the very near future. My display tank lights are being run for 4 hours a day right now. They are turned on at 11:00a.m. and are shut off at 3:00p.m. My tank is sitting not far from a sliding glass door and a window. So they get a bit of natural light in the morning and in the evening and that is why I am running my main lights for a shorter time. Plus, it is more natural I feel this way, because the light intensity is more gradual as the sun rises and sets. The tank gets to experience a little of this transition that way as well. These lights will be run on a timer soon too.
(8/17/12) Algae Screen Growth Update
(8/18/12) Algae Screen Growth Update
Algae Scrubber Screen Update (8/19/12)
Update 8/20/12Click thumbnail to view full-size
We Have Green Hair Algae! (8/23/12)
I haven't updated this Hub in a few days because I wanted to just let my algae scrubber do its job and not look at it every so many hours. I tell ya, it's addicting! But I am happy to report that I have a good amount of hair algae growing on the screen. I am very impressed and when I take it out of the tank to clean it I will post the pics. I plan on cleaning it on the 26th or 27th. This will be roughly 14 days from when I started it. Stay tuned for that!
I have done a little tweaking with the lighting period and I think this has resulted in the algae really taking off in growth. I will explain later what times I have my screen lit.
1st Algae Scrubber Screen Cleaning (8/25/12)
I decided not to wait until Sunday to clean my upflow algae scrubber screen. It is quite amazing to me how much algae grew in such a short period of time (from 8/20-8/25/12). When I looked into the scrubber from outside the tank I could see all kinds of hair algae growing and with the light shining on it it almost looked like it was glowing. Each hair was covered in bubbles both large and small. So I removed the scrubber, took some pictures, and then cleaned the screen. I have posted those pictures for all to see. The next I clean it I hope it will even be more covered with algae :)
I had altered my lighting schedule and when I did, I started to get really good growth. Instead of increasing the photo period, I decreased it. In addition, I made sure that when the display lights were on, the scrubber was off.
Lighting schedule for algae scrubber
4pm to 12am on
12am to 5am off
5am to 10am on
10am to 4pm off
Lighting schedule for display tank
10am to 4pm on
4pm to 10am off
2nd Algae Scrubber Screen Cleaning 9/1/12
On August 31st I inspected the scrubber screen and was surprised and overjoyed because it appeared that there was substantial growth on it in only 6 days! I wasn't sure how long I should wait to clean it again so I decided that I would clean it on 9/1/12. This would mark 7 days from from previous cleaning. (previously I had waited about 13 days before cleaning it the first time)
I have included a picture of my algae scrubber screen as seen on 8/31/12 and cleaning pictures that I took on 9/1/12.
I probably could have waited a few more days to clean the screen because not a whole lot of algae came off the screen even though to my eye it appeared that there was a lot. I was worried that if I waited to long that my water would start turning green. So for my next cleaning I'm going to wait longer as an experiment to see what happens. I am going to see what kind of algae growth I get if I wait 14 days and whether or not waiting this long affects the tint of the tank water.
9/7/12 UAS Algae Scrubber Update
Ok, I recently cleaned my algae scrubber screen on 9/1/12 and I was going to try and go 14 days until I cleaned it again. But when I looked today my hair algae is growing like crazy! In fact, it is growing so wildly that the hair is popping out of the air holes that I have on top of my scrubber. I don't want to clean it yet because I want to see how long I can go before I have to clean it. Thankfully I was browsing over at my favorite website (algaescrubber.net) and I came across a forum thread entitled "Ruddybop's UAS test". Ruddybop has a freshwater uas and he posted a video about his growth. His is thicker than mine (not by much though) which makes me happy because that probably means that mine will grow as thick as his as well! But he is doing something unique with his algae scrubber screen. Because our screens are lit on only one side hair algae only grows heavy on one side. So what he is doing is turning his screen around so growth occurs on the other side too. My screen is set up to be flipped from front to back so I decided to do the same thing and so that is what I did tonight. Cool!!
I have been doing some other things to promote growth. I have a hang on back (HOB) filter by Aqueon. It is next to my uas filter. I drilled a hole in the top lid of the Aqueon and ran an airline hose to the bottom of my upflow algae scrubber. I created a siphon and now some of the waste that is being pulled up into the Aqueon is feeding into the algae scrubber directly. I'm feeding the algae! I measured the flow rate and it is giving the scrubber an additional 6 gph. At that rate, my scrubber is receiving close to a full tanks worth of water per day from just the siphon (my tank is 29 gallons and so about 24 gallons per day is going into my scrubber just from my Aqueon filter). This is over and above what is pulled in from the air bubbles flowing up across the algae screen. When I open the scrubber filter there is all kinds of food and detritus floating and bouncing around inside with the bubbles and the algae. Since I did this, my growth has boomed! Not 100% sure if that is the reason, but I like to think so.
I have also mounted on top of my aquarium under my fluorescent display tank lights a horizontal scrubber with a screen that is the same size as my uas screen. I use another air pump that feeds to an airstone that is inside a pvc pipe that runs from near the bottom of my aquarium to about 5 inches above the water. The water gets pulled up from the tank bottom and pours onto the screen (which has an acrylic panel under it) and then drips into an acrylic box that has holes drilled in the bottom. It then drips back into the tank after getting scrubbed over the screen. This screen only gets light when the main display light is on and when the uas is off. For about 5 hours a night both screens receive zero light to give the algae screens a break. This horizontal screen has brown and green growth on it, but nowhere near the growth of the UAS, but it is only meant to supplement the upflow algae scrubber when it is not on. I've already had to clean this screen once already.! The horizontal algae scrubber scrubs the water slightly differently than the the UAS in that it is being exposed to oxygen and CO2 from the air outside the tank, versus inside the tank and I'm sure my display lights are a different light spectrum as well. So hopefully it is filtering a different portion of my water.
Also, I was getting a lot of oily residue on top of the water that was dripping into the box from the water coming up from the tank via the bubbles. So I put a coffee filter in the box so the water filters thru it and leaves behind the oil before dripping back into the tank.
9/9/12 Pics of UAS Algae Growth on ScreenClick thumbnail to view full-size
9/9/12 Algae Scrubber Screen Cleaning
I know that I said that I was going to try and go 14 days between cleanings this time around but the hair algae was growing so long off the screen that it was popping up out of the scrubber and some pieces were floating off into the tank. So I decided to clean it and I have posted my pics of the screen. This cleaning is exactly 7 days from the previous one.