DIY Nano Algae Scrubber, step by step with pics

[InspectorGadget]

PLEASE DO NOT POST UNTIL I SAY THE LAST STEP HAS BEEN REACHED! This will take me some time to type it all out an get all the pictures right. Thanks guys and enjoy!

This is a step by step guide on how I built my nano Algae Scrubber for nano reef tanks. The Algae Scrubber is made out of black acrylic for my 44 gallon (with constant sump water volume) SPS reef tank. I designed this Scrubber to fit in my 20 gallon glass sump in an unuasable space above my baffles. My goal was to not spend that much money and be able to build something durable that had the following requirements: (1) Fit in my sump (2) effiencly help with removal of unwanted Algae and nutrients (3) Not spend more than $50 of my money(4) be as dark as possible with minimal light penetration to not have Algae growth in my sump (5) fit in my sump (6) be as silent as possible considering it is beside my bed. I have completed all these tasks with this build. Most Algae Scrubbers I see are expensive or way too big to fit in a tight space. Nothing against the DIY King (I love a lot of his stuff) but a light shining through the side of my sump just won't work for my needs. I chose acrylic because it's awesome, will last and with a little practice you can build a ton of stuff for your tanks. So here we go! But first:

*****WARNING******
I am not an electrician, I am a diy guy. This thread contains the use of electricity, power tools and your brain. I will not be held liable for your equipment, damage to your tank, livestock death, personal injury or death or anything else described in this thread that could harm you or anything you have. You are doing this project AT YOUR OWN RISK!!!!******;Vomit;Muted;Hurting

Difficulty: Depends. If you are proficient with the use of power tools and have had experience with acrylic, moderate. If you have no experience with acrylic or power tools, Hard.

Tools recommended: Dremel tool or 4" angle grinder (you can get both very cheap at Harbor Freight stores or .com), table saw with 80+ teeth saw blade (you could do this whole project with a $12 harbor freight dremel tool but your lines won't be clean and you will have more light leaking through), sharpie, PVC cutting tool (or table saw), pvc glue (optional), lighter or heat gun, wire stripper or needle nose pliers, tape measure, razor blade, super glue, drill bits with various sizes and optional soldering iron. You can make do without a lot of these items but you only as good as your tools.

Supplies:
-***Solid black acrylic sheet 1/8" thickness minimum. $12, for my project a 12"x24" sheet was needed: on eBay https://www.ebay.com/itm/282300342502

-Weld on #16 (this should be required (I previously had a small amount left over)), a 5th of a tube completed this project

-LED lights $7 ***IP68 rating only! This means they can be submerged in water. I verified that the LED's I got were the rating listed on eBay. Red and Blue needed 10x red 10x blue. https://www.ebay.com/itm/191879998067 This item was shipped from china, took two weeks to arrive.

-Various plumbing pvc $20, (5) 1/2" 90 degree, (1) 5', 1/2" pvc pipe, (1) 1/2" pvc coupler, (1) 1/2" pvc cap, (1) slip to female threaded npt 1/2" coupler, (1) 1/2" push connect to npt threaded adapter for murloc hose (depending on what piping you use you could need a male npt to barb adapter for 1/2" id nylon tubing)

-Optional Power head or micro pump ( I had a micro sicce pump that I used. Any small power head will work but high flow power heads will need a valve to control the flow) . You could plump off your overflow line but considering I use a bean animal overflow design, I chose not to. Also a power head version is easier to remove.

-Zip ties 6" length (I had some at home already)

-IMPORTANT- MARINE grade heat shrink $4. I purchased a box of these from harbor freight. Make sure you get the box that contains multiple sizes.

-12 volt power supply. I currently own a switachable 5A power supply powering 4 pc cooling fans, 12v solenoid and ATO relay on my tank. This power supply has no problem handling it all with the Scrubber. One can be purchased off eBay or amazon for around $8 (Chinese import). You can also purchase one on amazon.

-LED wire only 10' worth or less. I had scraps from my light project. I purchased 25' of it from amazon. You only need 18ga 12v wire with a positive/negative side (black and red).

-Aquarium safe silicon $4 from lowes or homedepot

-Superglue gel type, prefer Loctite gel

-Plastic Knitting mesh $3 at Walmart or your closest craft store or internet

I will post the pictures along with the steps. I will also do my best to describe various safety concerns and why I did what.
;Watching

 

[InspectorGadget]

***STEP 1****
First thing you need to do is measure the space you want the scrubber to go in your sump. The space I had was very limited so I decided to go with a box that will be 7" long, 4 inches wide and 4" deep (internal volume). I will have this box sitting 1/2" above my last bubble baffle and I did not want the box sitting in the water. You want the water to flow out of the box with a minimum water volume. Then design your box on a piece of paper. Take in account for the thickness of the acrylic. So if I want the internal dimensions to be 7x4x4" it would be like this : Example: My top and bottom pieces are the same size: 7 1/4" x 4 1/4", sides are 4" x 7" and ends are 4" x 4 1/4". The end pieces will weld onto the ends of the sides and then onto the bottom piece. I recommend a minimum of a 4" depth and 4" width if you use the same LED's I did. The LED's I used were 3" long as you will see in a few steps.

****STEP 2***
Using your design (or mine), use a ruler or stright edge with a your measuring tape and draw the lines you need to cut on the acrylic paper. This is just to make sure everything you want will fit. I recommend you design the box before you order the acrylic to make sure it all fits.

***STEP 3***
Time to cut. I recommended an 80 tooth blade or higher due to the thickness of his acrylic. I use a plywood blade to cut acrylic. Blade with less teeth are prone to break or chip the acrylic when it is this thin. I do not follow the marks I made on the acrylic sheet, they were just a reference point to make everything fit and have some good size scraps left over for the other steps. The 4" pieces I cut all at the same size so that I known they are identical. This goes the same with the 4 1/4" sides, etc. leave the paper on the acrylic. You need only remove the paper when you are ready to weld.

****STEP 4**
Using a piece of paper, draw the side of your box (7"x4"). Now take your led's and lay them out on the paper. Once you figure out the orientation, you are good to go. I took one red then a blue then a red then a blue etc. until 5 red 5 blue would be on each side. Weave the wires in and out to get the led's to fit together. In the pictures I changed my design slightly after I had glued the LED's lol so I am short an led on each side. (Remove that junk 2 sided tape that comes on it also). Step 6 should be done next. Then plug up your LED's and make sure they work before gluing.

****STEP 5****
Glue the LED's you layed out on the paper to the acrylic sides you cut. Same orientation. Make sure you lay the first light as parrelel to the side of the acrylic so all your other LED's line up straight. Considering it came with double sided tape, I placed the superglue gel on the tops and bottom. Just enough glue to cover the spot. Push and hold in placed for a minute or so. Then move to the next led. You want to cut the led wires as little as possible. I cut the end of a string and the start. I tried to make the ends cut land on a section that will be above water. After gluing, visually inspect each led for anything that isn't waterproof. A few of these looked like the wire contacts were coming out of the led sealant. As a precaution, I used the aquarium silicone over all the contacts and anything else I was worried about for safety.

***STEP 6***
The reason I used marine grade heat shrink is that it's meant for saltwater conditions like on boats. I cut a small piece of heat shrink and placed it on the cut end of the string of LED's. Using a grill lighter, I heated the heat shrink until I could see the special glue come out of the ends of the heat shrink (this seals off the attachment). Make sure you use a heat shrink piece a diameter very close to what your are sealing. Once the ends are sealed, strip and attach your postive and negative wires to the other side of the led string (the side that will be out of any water contact).

 

[InspectorGadget]

***STEP 7***
Time to start welding. You want to weld the end of your side piece to the face of your sides (the portion that you made 1/8" larger on each side, 4 1/4" wide). Makes sure you don't mix up the 4" part with the 4 1/4" part of the end. This would cause the ends to stick above the top of the sides. You want the sides to be flush with the ends so the top sits flat. Before welding, I used electrical tape to hold one side of the pieces together then on the other side I placed a plastic carpenters triangle with the bottom edge cut on the side panel. This was held into place by a piece of elctrical tape. You want to use weld on #16 along the side of the side piece to be glued. I laid the end flat on my counter top and placed the end of the side piece with weld on #16 onto the end piece. Repeat on the other sides. Make sure the top parts of the side are both at the right location. You don't want your wire ends not to both come out at the same side.

***STEP 8***
Now, you need to prepare the bottom piece. Before you weld, you need to cut holes for your drains. A dremel works best for this. Mine unfortunately died and I used a hole saw but instead. If you have a dremel, place an end of the 1/2" pvc on the bottom piece. Using a sharpie, draw a line around the pipe. Make sure you make your holes far enough away from the walls to accommodate a 1/2" pvc coupler (details later) but not in the middle where the wire mesh will hang down. You can see an example in the picture above. Now when they are in the right place, cut them out. Prior placing the bottom piece for welding, add anymore aquarium to wires on the side pieces while you have easy access still. Now, weld the box frame (two ends and two sides you welded) to the bottom piece. Place a bead of weld on #16 around the whole frame edge then push the frame and bottom together on a flat surface. You then can set a few books on the top to help bond it together. Let the weld on sit for a few hours before moving. Same when welding the sides.

 

[InspectorGadget]

****STEP 9***
Time to prep the top while everything else cures. This will take several steps (for a good reason). First, on the top piece, measure 1/8" in on all sides. This simulates the box that it will be sitting on (the lines in the center of the picture are meant for the other side). Lines around the perimeter in the picture.

Use a straight edge to draw the lines creating a box. I used a razor blade along the straight edge to mark the acrylic. This is a good step considering you can't see sharpie on the smooth black acrylic once the paper is gone. The razor mark gives us a line that we will need. Once you make your box, turn the top over to the other side. Now, find the center line of the top going long ways (should be at 2 1/8" from the corner) make a straight line. This is where the center of your pvc pipe will sit. Now comes the tricky part. Cut approximately 1/2" wide slit along the line you drew on the top starting about 1/2" off the ends of the the top. Cut this using a dremel tool (I used a 4" angle grinder with a steel grinding disc). MAKE SURE YOU DO NOT CUT THE TOP IN HALF. After you cut the 1/2" slit, use a dremel tool (or angle grinder) to bevel each side of the slit. This is very important. You will see what later. Reference the picture:

Next: This a very tricky part also. Measure the inside of your box. Should be 4" x 7". Using the scrap acrylic you have, cut to slivers of acrylic that are 1/8" in thickness. Two end pieces and two side pieces. End pieces should be 4" and side pieces should be 6 3/4" (this makes them fit together just like our box. Be very careful when cutting these pieces. When you cut them, use a piece of wood or pvc to push the acrylic into the saw. Stop the blade approximately 1/2" from the end of the cut so that your piece doesn't fly across the room. Manually cut the remiaing 1/2" with a dremel of angle grinder. The slivers you just cut will be placed on the top on the side where you drew the box using a razor on the acrylic. Place the slivers on the top to make sure everything correctly. These slivers are used to keep the lid from moving around and block light from getting out. Now use weld on #16 and glue the slivers to the lid. Place the slivers against the line you drew with the razor. Make sure you place the slivers on the opposite side where you cut the beveled slit into the acrylic. Reference picture:

Hold the slivers in place a few seconds until they stay flat. Proceed to next step.

 

[InspectorGadget]

***STEP 9****
Move on to the pvc top pipe. Now cut a piece of pvc to approximately 10". This just gives you room to play, we will trim some more in a minute. Now, lay the pvc flat on a flat surface (its best to place the end cap and 1 90 degree piece on the ends to hold the pvc still) and use a sharpie (with the lid off) to draw a line along the pvc pipe. I used a piece of acrylic to place the sharpie on before drawing the line. This creates a center line on the pvc.

Now place the pvc on your lid and made a mark of the ends. Then come in a 1/2" and make another mark on the pvc. Now, use a drill bit to drill a ton of holes along the center line you drew but inside the end marks you drew. I spaced the holes approximately 1/8" apart. I don't know the size drill that I used (had a random bag) but it was slightly over a 1/16" drill bit. Maybe a 3/32". Don't go over 1/8". After you are finished drilling the holes it's time to cut a groove in pvc, over the holes, along the center line you drew. I used an angle grinder to do this. If you do, you run the risk of cutting through the pipe. You just want to dremel a groove into the pipe, not cut through it. Using a grinding stone on a dremel would work. Cut a 1/4" grove in the pvc.

Now cut the ends of the pipe until the cap and 90 degree bend sit almost against your top lid (make sure you keep all your holes you drilled in the center of your lid, this is very important). The best way to do this is to place the pipe on the lid where you can see the holes you drilled and make sure you don't take off too much pipe on each end.

****STEP 10****
Now, using the scrap acrylic you have, cut two identical pieces that are the length of your lid (7 1/4") and 1/2" in width. Now, pull one zip tie from the bag of zip ties you purchased. Go in an inch of each corner and draw a mark that is the width of zip tie. Then do one in the middle. You should have 3 marks. Make sure you place the two pieces together and make the marks at the same spot. Now, using a dremel tool or angle grinder, cut the spot you just marked just until a zip tie sits flat in the grove. You should be able to sit the acrylic on a flat surface and slide a zip tie through it. You don't want to cut too much where you have a very loose zip tie.

 

[InspectorGadget]

***STEP 11*** Almost there!
Now, take the two pieces of acrylic where you cut the grooves in and you are going to weld them to the lid. You will be welding to the top side where the groove you cut in the lid is located. Take the piece of 1/2" pvc with the holes in it and place it in the middle of the two pieces. Make sure that the zip tie slits you cut match the opposite piece so that they line up. Now place a bead of weld on along the edges but stay about 1/2" away from the slits. Now with suing the pipe and two pieces of acrylic, press them against the lid where you can see the holes through the bottom side of the slit in the lid. You can move the piece into position for a few seconds until the Weldon digs in. Make sure the two pieces are pressed against the PVC pipe. Hold the pieces in place for a few minutes.

Once it has dried, proceed to the next step.

***STEP 12***
The only portion of PVC that I glue together is the end cap and the first 90. This makes it safe just in case a cap pops off and would spew aquarium water everywhere. Glue the end cap and first 90 on. Make sure your 90 is aimed straight down (to make sure your pump will connect from your sump). Then you can cut a small piece of pvc to go between the 90 and the slip/threaded coupler. This is basically your Union. You can pops this piece off when removing your lid for Algae cleaning.
****STEP 13***
Time for the mount. Really this can all depend on your setup. Even though I made this for a glass sump (20 gallon aquarium), the concept could work for a acrylic sump also. I used some 1/4" thick clear acrylic laying around for mine but you can use some of your scrap leftovers no problem. I designed this to go from one side of the sump to the other (that's why the box is 7 1/4" long). My sump measures 11 9/16" where an aquarium lid would sit. I cut to long pieces of acrylic that are 11 9/16" long and 1" wide. I then cut a 1/2" by 3/4" notch on each side of each bracket piece (if you don't have long pieces you can cut 4 small brackets for each corner). I then welded the acrylic to the box 1/2" from the top. This allows the box to sit slightly above the bubble baffle and slightly above the sump. You will have to design these in accordance with your mounting needs.

I mounted my brackets 4 inches off to one side so I had space for pump lines and other equipment.

****STEP 14****
Use the one pvc coupler to create 4 small coupler slivers. I basically cut the coupler into 4 pieces minus the center piece where the pipe stop is located. Cut two small sections of pvc from the 5' you purchased that is approximately 4 inches long. Glue a coupler sliver on one end of one pipe and on one end of the other. Make sure the coupler slivers are at the very ends of the pipe. Now slide the two pipes into the two holes you crater in your box bottom. The coupler slivers will stop the pipe from going through. Now, make a cut in the two remaining coupler slivers. They should be easy to slide on the opposite side of the pipes, on the underside of the box bottom. This creates a "bulk head" and keeps the pipe in place. Glue the slivers in place on the bottom. After pvc glue has dried, run a bead of silicon on the bottom and let it dry. Proceed to place a 90 degree bend on each pipe. I then placed a another 90 degree on the ends to make the pipes point upward. For me I did this so no light could reflect through the pipe. This is not required. Reference above picture.

 

[InspectorGadget]

***STEP 15***
Drill holes for or cut slits in the top to allow the wires for the LED's to go through. I chose to drill mine. Be very careful if you do because if you drill with too much pressure or on low rpm, you can crack your acrylic. I barely placed and pressure on the drill and had higher rpm so it didn't "catch" on the drill bit. Best case is to start small and work your way up. I used a drill bit that fit all 4 of the wires through from each side. Tight fit. Drill the holes at the top of the brackets so that the wires won't be near water on the outside or hit the side of your slump. If you choose to slot instead, you can cut using a dremel or grinder a slit on each side. Only cut enough to fit the wires through and that won't hit the inside of the lid.

***STEP 16***
Wiring. Cut the wires to length on both sides for the 4 sets of LED's and cut a long piece of wire that will connect to your power (2 red and 2 blue you installed). Strip the ends and twist them together with the main power wire. I twisted all the reds together then all the blacks. It creates one big bundle. This is the only part of this build I used solder. I do not suggest it for any of the other connections. Solder contains lead and tin and don't need to be in your aquarium. I used solder on the big bundle to hold all the wires together. This is not required. You can just strip long portions together and twist it.

Prior to soldering, make sure you slip on your heat sink and large enough to cover the bundle. After that I placed another , smaller heatsink to cover the positive and negative wires to make sure no water can get to the wires. After this is completed, use silicon or super glue to fill the holes you drilled in the side of your box so no water and drip from that point due to evaporation.

***STEP 17***
Water test. This can be VERY DANGEROUS. I filled up a 5 gallon aquarium I had with 4 gallons of water. The safest way to do this is to buy a few fuses and hook them in line on the power side of your wires. Use a fuse that's the same amps as your led consumption. You can use some electrical tape and twisting of wires to get this to work. Plug it into your 12v power supply. Then place the box in the water and plug your power supply into the wall. Hopefully nothing exploded! Should look like this:

The LED's are flippin bright! If test passed, move on. If not, check all your connections. Make sure you didn't melt the wire rubber when melting the heat shrink. If you took the precautions I did, everything is over siliconed (everything but your led lights).

 

[InspectorGadget]

***STEP 18***
Finish the lid. Now place three zip ties through the slits you made in the top lid. Should look like this

Notice in the picture I place the plastic mesh in already but you can use the zip ties to see where you need to cut. First cut a piece of plastic mesh that fits the notch that you cut in the top PVC pipe. The notch allows the mesh to stay in place. Mark the mesh using a sharpie at the three points where the zip ties are. Using a razor blade, cut a few of the top squares in the mesh, where you marked to allow the zip ties through, but don't cut the top line. Examine the picture above. Now place the top PVC pipe on the zipties and close the zipties where the pipe can still move but not be completely tightned. When the holes line up in the top lid, the plastic mesh should "lock" into the pvc notch.

This is why you beveled the acrylic at the slit in the lid. It allows the zip ties to go around the pvc pipe. Once the holes are in the right place and mesh hangs down nicely, tighten the zip ties. I placed a tiny dab of superglue on the sides of the pvc on top to make sure the pvc doesn't rotate. Don't need much just incase you want to remove that pipe or the plastic mesh. Now cut the plastic mesh to length where it fits in the box and doesn't bend on the bottom of the box. Install the lid and see how it all fits!

***STEP 19***
Install pump. It worked better for me to install the line on the pump then place it in the sump then connect it to the box. Most powerhead or small pumps have a 1/2" outside diameter output (measure yours). You can either use a 1/2" push connect coupler or be cheap like me and use a small piece of 1/2" id nylon tube to join the pump and the 1/2" murloc (ro/di line) line together.

***STEP 20****
Install the box and turn it on!! Yay! The pictures below show my install. The LED's are so bright that the pvc pipes are glowing. Not much light at all leaked through. The reason I did LED's on each side is to allow better surface area to allow algae to grow. Enjoy guys!!

 

[InspectorGadget]

 

[InspectorGadget]

Finished!!!! Turned it on last night. We will see what we have in two weeks. Any questions?

 

[AngryOwl]

Update?

 

[InspectorGadget]

Good and bad.

Good: Positive Algae growth, it worked

Bad: As I test, I ran it 24/7 for well over three weeks. I could feel the LED's getting hot. Inside the box the temperate stayed around 86 degrees. Made zero changes to my water temperature. I check on the box daily to see what's going on. One day two weeks ago I saw the light was dim. Opened the top and saw 5 or so of the led strands had burned out. The heat was too much for the protective coating and melted. The LED's then shorted out. I caught it before anything bad happened besides LED's burning out. To prevent this issue, I suggest not running the box 24/7, try to get better LED's that aren't cheap Chinese made and allow vents at the top of the box for better air circulation.

 

[AngryOwl]

Thanks for the update. I started one about 2 months ago and can't get it go grow green. Just grows diatoms and black growth that needs to be scrapped off with a brush. I'm running RapidLEDs two sides with 4 reds (660nm) and 2 blues (440nm) with adjustable dimmer. First 3-4 weeks ran them at 18 hours a day at maybe 10-20% power. Then read something online suggesting they should only be on 9 hours. Results have been the same for both periods. I've been attempting to turn up the power a little bit. I'm interested on your thoughts... especially that you started off running yours 24/7.

 

[Andnosobabin]

I've read a 3 blue to 1 red led is the optimum color ratio for cheap leds to get close to correct spectrum. Is there any merit to this?

 

[AngryOwl]

I've read a 3 blue to 1 red led is the optimum color ratio for cheap leds to get close to correct spectrum. Is there any merit to this?

hmm... I've never found that information anywhere in my searching. I would say based on my results it would be hard for me to say its true. Once I added more reds I got results right away.

 

[Andnosobabin]

hmm... I've never found that information anywhere in my searching. I would say based on my results it would be hard for me to say its true. Once I added more reds I got results right away.

There's a good chance it was the opposite of that. It was regarding chaetomorpha reactors and light strips. I'm not home or I would be able to find where I read that.

 

[Reeferoppe]

Any update after all these years

 

[AngryOwl]

Any update after all these years

Mine never really did anything and eventually the LEDS failed. I would recommend a cheato reactor if you have the space.