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HOG3 Hang-On-Glass® UAS® Upflow Algae Scrubber® with Green-Grabber surface - 3 cubes feeding per day


Eliminate water changes. Remove nuisance algae, nitrate and phosphate. Cultivate seaweed for feeding!!!



HOG3 dimensions: Each cover is 6 5/8" wide x 8 3/4" high x 1 1/2" thick  (16.6cm wide x 21.9cm high x 3.75cm thick).


Operates on both 120 and 240V.


***Can ONLY be shipped in USA.***


No dangerous metal 240/120 volt lights.


Welcome to algae scrubbers. We are the only source for patented upflow scrubbers: U.S. Patent 9,115,008 and 9,708,207. All the oceans, reefs, lakes and rivers are naturally filtered only by algae, and all the organic particles remain in the water to feed the creatures. Reduce your glass cleaning and water changes, and create an environment for living micro-animals to grow inside the scrubber. No more dosing or possible overdosing. No more refilling. No more pale corals from low nutrients, and no more sick animals from high nutrients. Far more powerful than chaeto or refugiums, and does not remove the food particles. And you can use the algae as food!


Get the no-overflow advantage of an upflow scrubber: since it is ALL underwater, it can't overflow onto your floor. And now, all six of the magnets that go in the water are protected by a hard plastic cover inside of the black silicone; this prevents any scrapes or rust if you happen to accidentally let the magnets snap together. 


This is the first larger Hang-On-Glass version of the standard HOG.5,  HOG1  and  HOG1x algae scrubbers, which were the first HOG scrubbers available. This HOG3 offers much larger algae-attachment space to hold more growth between cleanings, and it is 2-sided instead of 1-sided because of the strings; 2-sided allows light to reach further into the growth. Also, stronger magnets attach to thicker aquarium walls up to 5/8" (16mm) glass or acrylic. If your tank is larger than a nano, then you can consider this model if you feed a lot.


This HOG3 Scrubber has 36 square inches (225 square cm) of two-sided algal growth surface textures and strings, which once growing is designed to absorb the nutrients from this much feeding per day: 


3 Frozen cubes, or

30 Pinches of flake, or

30 Square inches (180 square cm) of nori, or

8.4 grams of pellets


The number of gallons or liters of water in your tank or sump does not matter. If you feed more than the above amounts you can get multiple HOG3 units; multiple units are preferred over one larger unit because you can clean one unit per week, and because you'll always have one unit filtering while the other one starts growing again after a cleaning. Multiple units are also good for backup. The magnets attach the outside cover to the inside cover through the aquarium wall, and can be used on glass or acrylic 1/4 inch (6 mm) to 5/8 inch (16 mm). Not more. If your aquarium wall is 3/4" (18mm) it might work but you won't know until you try; it would be better to put the HOG3 in your sump instead; it will work the same. 


Compared to the HOG1.3 and HOG2 which look the same in size, the HOG3 is meant for situations which have nutrient or algae problems, even in cases where the rocks in the display are covered in thick green hair algae.


The large inside space of the HOG3 growth compartment allows for lots of build up of algae, but most importantly the 6 LED light provides the strongest photosynthesis of all the HOGs, giving it the best chance of out-competing the scrubber on your rocks. Also, the 6 LED light grows green algae in situations where the lower power of the HOG1.3 or HOG2 would only grow brown algae. So this HOG3 model is great for aquariums that have been running for years and are showing signs of old tank syndrome, or in highly-fed predator or NPS corals tanks. 


The strings (ribbons) in the growth compartment of the HOG3 are the same strings that are in the SURF2 and SURF4, and are the heart of the ability of the scrubber to be able to use all the space for initial growth. The HOG1.3 and HOG2 have to grow outward from the textures before the open-area of the compartment is filled in; however the strings on the HOG3 allow this middle open area to start growing immediately, and to do so using 2-sided growth (strings are 2-sided in growth) instead of the 1-sided growth of the textures alone. Thus the compartment fills much faster with growth, and faster growth causes stronger photosynthesis (filtering).


The Green-Grabber (tm) algal growth surface is so rough and prickly that it might be the roughest thing you've ever felt. A cactus might be sharper, but that's about it. Rough surfaces are critical for allowing algae to attach and grow and thus provide strong absorption of nutrients. The rock-hard protrusions stick straight out 1 to 3 mm. Old style algae scrubber screens are made from "slippery" plastic canvas that is used for sewing and knitting; algae takes a long time to attach to it. Green-Grabber (tm) growth surfaces are not plastic at all; instead they are rock hard and have jagged rough edges and points (don't let children play with them). 


This is a hand-built Hang-On-Glass® (HOG) Upflow Algae Scrubber® (UAS®) with strings and a Green-Grabber® growth surface, for glass or acrylic 1/4 inch (6 mm) to 5/8 inch (16 mm) thick. 


No electrical parts go inside the aquarium; only air. This HOG3 will run on both 120V and 240V, and comes with a 10 ft (300 cm) power cord with a U.S. plug.


Comes with 3 ft (90 cm) of vinyl airline, but requires an air pump that can pump at least 2.0 liters per minute (.07 cfm), preferably more. A pump that says it can handle 2 or more airstones/outlets, or a pump with 2 tubing attachments instead of one, will be needed. You can have as much air as you like, however; 10 lpm pumps are no problem (although it will be louder). One powerful pump which works exceptionally well is the Whisper AP 300 from Tetra. 


Comes with 6 red (660 nm) 3-watt LEDs, which are attached to a heat sink inside the cover; the cover does get warm. The LEDs will give the aquarium or sump a slight red color at night when the aquarium lights are off. You will need to get a timer so you can run the LEDs for up to 22 hours per day (not 24). The LEDs never need replacing. 


The HOG3 growth compartment will need to be cleaned every 7 to 21 days, by removing the inside cover, disconnecting the airline, and taking the inside cover to the sink so you can brush the algae off of the growth surface and the bubbler with a toothbrush, and off of the strings with your fingers. 


Visit the Santa Monica Filtration Website for the full description: