for saltwater sumps
No dangerous metal 240/120 volt lights.
waterproof submersible GEM5® lights, Green
screen, and pole mount.
remove nuisance algae, nitrate and
Cultivate seaweed for feeding.
Videos of smaller RAIN2:
RAIN4 product dimensions **without** pole
mount: 10" long x 5" wide x 13" high (25cm long x 12.5cm wide x 32cm high). Dimensions with pole
mount will depend on your choice of pole mount segments.
Operates on both 120 and
240V. Can be shipped to
any country; you can find shipping costs by putting the item into
the shopping cart; be sure to click "display rates"
No dangerous metal 240/120 volt lights.
Welcome to algae scrubbers. We are the only source for patent pending
waterfall scrubbers that use our new dome/tray combination. All the oceans, reefs, lakes and rivers are
naturally filtered only by algae, and all organic particles remain in these waters to feed the animals. 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 of chemicals. No more refilling media. 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 any food particles. And you can use the algae as food!
The RAIN4 will do most of the filtering needed for your saltwater aquarium, and in most cases it will do all the
filtering if it is the proper size for your amount of feeding that you do and the amount of rock that you have. Part
of this filtering includes helping eliminate two very important things that drive most aquarium owners crazy: Algae
and waterchanges. The filter works by growing algae on the screen, and these algae consume all the "bad" things out
of the water*. This is how all the oceans, and all the lakes, are naturally filtered.
Because of the high filtering photosynthesis of our scrubbers, it's not
recommended to run them with macro refugiums or chaeto reactors, because the macro or chaeto will die and
the nutrients will be absorbed by our scrubbers.
From the inventor of the original waterfall algae scrubber in the year 2008
finally comes a larger version of the popular ATS waterfall RAIN2: the patent pending RAIN4. The underwater
submersible and electrically safe GEM5 lights (also patent pending) allow the RAIN4 to be placed in your sump
anywhere you like, as low to the water as you like, which saves a lot of space. And the pole mount (included
with the RAIN4) means you don't even need a shelf or a bracket to place the RAIN4; just use the pole mount to
set on the bottom of your sump. You can fit two RAIN4 units into the same space that other waterfall algae
scrubbers take for just one of their units.
The pole mount that is included with the RAIN4 is recommended for the
easiest and most sturdy operation, and it has multiple height adjustments. However the pole mount is
not mandatory; you can use a shelf or other technique to mount the RAIN4 similar to the smaller RAIN2 if you
Safety is a prime concern, and our GEM5 lights keep the 240 or 120 volts far
away (2 meters way), with only a safe low voltage going into your sump area. The system is so safe that you
could cut the GEM5 lights in half and put them in saltwater and nothing would happen. Other waterfall scrubbers,
however, use so-called "waterproof" Chinese lights that are bolted onto the outside of the scrubber box, and the
240 or 120 line voltage comes right into the sump area. Not only are these lights not waterproof (don't ever put
them in water), they are not even water resistant, and salt creep will eventually get inside them, causing an
electrical hazard. Our power supplies are UL and Canadian UL certified. The Chinese lights that
others use, are not.
Also included with the RAIN4 is a 2 mm thick, 2 sided, patent pending Green
Grabber® algae attachment screen. The screen is also sold separately HERE for DIY, and it is the modern replacement for the old hand-scrapped plastic
screens. It is 3D printed in Rough 3D (TM) and has far more algal-attachment
surface area than hand-scraped screens. Also, similar to our air bubbling upflow UAS scrubbers, the screen
of the RAIN4 is surrounded by air so that when algae growth is strong on the screen, the algae can get the
carbon it needs from the CO2 in the air (instead of from the alkalinity in your water) after the CO2 in your
water is used up. Thus the scrubber growth (filtering) is not limited by your alkalinity and CO2 in your water,
and your alkalinity will stay at higher levels. This is compared to sealed chaeto reactors which don't contact
air and thus must get all the carbon it needs from your alkalinity, which causes the alkalinity to drop
faster, and the growth to slow down.
The RAIN4 comes with 6 of our GEM5 lights, which will be already mounted to
the inside of the dome lid cover. The GEM5 lights are also sold separately HERE and you can add more of them to the dome lid by using silicone glue if you wish.
The RAIN4 also includes 2 power supplies (the RAIN2 only has one) so that you can start off with fewer lights
when needed, and can control them easier with a controller if you have one. Two power supplies is also great for
backup, in order to always have some of the lights operating (photosynthesis water filtering only works when
Aquarium size: The RAIN4 has 48 square inches of
2-sided growth surface and is designed to be the only filter on an aquarium that is fed up to:
4 frozen cube per day, or
40 pinches of flake food per day,
40 square inches (240 sq cm) of nori seaweed per day, or
0.4 dry ounce (11.2 grams) of
pellet food per day.
The amount of water in the aquarium, or the dimensions of the aquarium, are not
important. If you feed more than the above amounts, you can use additional RAIN4 filters (or use our SURF, HOG
or DROP filters) to add up to the amount that you are feeding, and then clean one of them at a time on a
rotating schedule (one per week, etc). If you feed much less than these amounts, and the aquarium is very small,
then it will still work but you just need to find a place where the filter will fit. It’s not possible to
Click the "image gallery" button above for more
pictures, or click here:
Drain Pipe: Although a
drain pipe is not needed, you can add one by using a standard 1” ID drain bulkhead which fits
standard 1” (25mm) schedule 40 pvc pipe. The drain hole in the tray is 1 ¾” (44.5mm) diameter.
Head Room: If you are installing the RAIN4 in a
sump or cabinet area with limited space, the RAIN4 needs only 2" (10cm) above the top of the
light-cover dome lid in order to lift the whole tray unit up off of the pole mount, and then you can
remove the light-cover dome lid from the tray.
If you commonly have power
outages, all other waterfall scrubbers will dry out after a few hours, but you can
prepare for and prevent this with your RAIN4 scrubber by placing it low enough in your sump (even
slightly underwater if needed) so that when the power goes out the water level in the sump will rise
up high enough to keep the screen under water. The GEM5 lights will not be harmed at all because
they are designed for underwater use. With the screen submerged like this, it can last for several
days with no flow or light. Do not ever try this technique with other waterfall algae scrubbers
because it would be a serious electrical hazard.
The GEM5 lights can be put on a timer so that they stay on for part of the
day, and off for the rest of the day, to possibly improve growth and filtering. However you can try
24 hours of light (no timer) if you like because sometimes it does work well in saltwater with high
measured nutrients such as more than 1.0 ppm phosphate. But generally, algae need dark time to rest,
so plan on getting a timer, especially on a new tank with low nutrients.
The RAIN4 requires a water
pump that can pump at least 200 gph (760 lph) water flow 24 hours a day. 300 gph
(1135 lph) might be better to fill up all areas of the screen. The height (“head”) of the filter
above the sump water level will require that the pump be able to pump up to that level and still
be able to supply enough water. Generally, a 400 gph (1500 lph) pump with an adjustable output
works in most cases. The water can also be fed from your display overflow; any type of overflow
system (Herbie, Durso, siphon, etc) will work.
RAIN4 will run on both
120V and 240V, and comes with two 10 ft (3 m) power cords with two U.S. plugs. If you
require different plugs you can get adapters at any local hardware or travel store, or online, or
you can cut off the U.S. plugs and install your own plugs from a hardware store. They are simple
2-prong plugs, and no transformer is needed. Or you can use laptop figure-8 cables from any country;
it plugs right into the power supplies.
* Water Changes: If you have been doing water changes to reduce nitrate,
phosphate, or nuisance algae, then an algae scrubber filter will greatly reduce the need for them and
may possibly eliminate them. When algae grow in the filter, they consume nitrate, nitrite, phosphate,
ammonia/ammonium, metals, CO2, and some toxins; so it’s just a matter of growing enough algae inside the
filter to do the filtering you need, compared to how many nutrients you are putting into the tank with
the food you feed (that is why the RAIN filter is sized for a certain amount of feeding per day).
However, this filter (and algae in general) do not supply calcium, alkalinity, magnesium or strontium.
So if you wish to reduce or eliminate water changes, and have stoney corals, you will need to supplement
any calcium, alkalinity, magnesium or strontium that you were depending on water changes for. Freshwater
aquariums, which may only need alkalinity (hardness) to be maintained, may get enough alkalinity from
just doing evaporation top-offs with tap water from your sink.
This RAIN4 (except screen) comes with a 1 year
warranty: The Green Grabber screen comes with a 6 month warranty. Warranty is for replacement or repair only; not a refund. Costs for shipping back
to us are not covered; you will need to ship the entire unit back to us before we can ship a
replacement. Warranty is limited to repair or replacement, and does not cover fish loss, personal
injury, property loss, or direct, incidental or consequential damage arising from the use of it. The
warranty and remedies set forth above are exclusive and in lieu of all others, whether oral or written,
express or implied. We specifically disclaim any and all implied warranties, including but not limited
to lost profits, downtime, goodwill, damage to or replacement of other equipment and property, and any
costs of recovering animals, plants, tanks or other aquarium related items and/or equipment. We are not
responsible for special, incidental, or consequential damages resulting from any breach of warranty, or
replacement of equipment or property, or any costs of recovering or reproducing any equipment, animals
or plants used or grown with this product.
Can be shipped to any country;
you can find shipping costs by using the shopping cart; be sure to click "display rates". If you don't
have a zip code, enter "zip code" instead. Note that shipping outside of the USA will probably require
you to also pay an import charge when it arrives. We cannot mark it as "gift". The lowest cost (but
slowest) foreign shipping is generally USPS Priority Mail International, but USPS Priority Express
International is faster. The size of the shipping box is 30 x 12 x 12 inches (75 x 30 x 30 cm) and the
weight is 15 pounds.
RAIN4 product (not shipping box)
dimensions **without** pole mount: 10" long x 5" wide x 13" high (25cm long x 12.5cm wide x
Operates on both 120 and
be shipped to any country; you can find shipping costs
by putting the item into the shopping cart; be sure to click "display rates"
No returns; please make sure this is the model you need.