Review: KollerCraft TOM RP3 Overflow Box

Discussion in 'Fish Tank Filters' started by Stickyickyooo, Jul 3, 2016.

  1. StickyickyoooNew MemberMember

    Alright ladies and gentlemen lets get this show on the road! I'll be showing you today or right now the KollerCraft TOM RP3 Overflow box. If you don't know what it is, no worries I'm here to show you about this bad boy. Let’s start with what the manufacturer has listed for its specifications. ** I'm just using the overflow box and tubing, not the canister filter that may also be sold with this, I used this unit to connect my display tank to a sump tank underneath it.


    This unique Overflow Box allows for easy connection to sump-style filters without aquarium modification. Rapids Overflow Box offers a simple and effective alternative to drilling aquariums. Innovative overflow with built-in venturi system automatically primes and initiates water flow to filter sump quickly, quietly transporting aquarium at flow rates much greater than units utilizing siphon tubes. No tubes or manually priming required, automatic starts filter by innovative venturi system. Plus Overflow box offers anti-siphon prevention preventing aquarium water from draining back into the filter in event of electrical power loss.

    Capable of handling pumps up to 950gph flow rate
    Mounts to tank frames up to 1.75" thick
    Built-in anti-siphon feature prevents flooding, automatically primes and starts water flow back to filter when electrical power returns
    Ideal for use in aquariums that would benefit from sump filtration, but lack pre-drilled Reef Ready permanent internal overflows
    Measures 8"L x 6.5"W x 7.5"H.

    When I first saw this I was like no way! I have to get this. I've been thinking about a sump for a long time and your telling me this box does it all, but lacks the pump? So i went ahead and bought the sucker off of A to Z Amazon. I actually have some unboxing pictures this time and here they are.

    [​IMG] [​IMG]

    This is the main body of the filter that pretty much does it all except water changes.

    Front side of the box, where the outflow and skimmer area is. More on the skimmer area later....


    The outlet and inlet for the water flow. The outflow is 1' 1/4" diameter with the inlet being only 3/4"
    This is the screw that secures it to your tank, it extends a good portion. no worries if you have a big gap to cover.

    The hoses themselves, you can look for yourself and see which one goes where, if not I'll help you. The big one if for outflow (water flowing out of the main tank going to sump) and the small one is your return line (water flowing from sump back into main tank.


    The hoses stretched out measure roughly a little over 40"s for one, If you need a longer run consider buying some more on your own.

    Setup on the unit was disappointing. It was way to easy. I thought I missed some stuff, but no really I had everything set up correctly. I've taken some shots of the instructions. Check em out.

    [​IMG] [​IMG] [​IMG] [​IMG]

    See told you installation was easy. Just connect the tubing to your sump. That's for you to decide on how you want it. Make sure you have a return pump connected to the return hose and its connected with the return portion of the box. Fill the Sump and the Overflow box up with water, but don't fully fill up your sump. Your going to need to find your maximum limit line(max amount of water you can have in your sump). It took me awhile to figure it out, because this thing is kinda finicky. Once it's dialed in your good to go though. Once you have water in both just cut the pump on and it should automatically start everything. It was amazing to see the first time. Water being pushed out and water started get sucked in, but warning I had to cut the pump off several times to add more water into the sump. There was absolutely no priming, no jiggle this or that, just simply make sure there is water and turn on the pump. It started functions on its own, just make sure its hooked up properly.

    I've used this unit for roughly about 4 months now, so i decided to write a review on it. The unit is rated for 950 GPH, but I have not pushed it that high. Once I hit about 400ish GPH the skimmer gate started causing issues. Hence why i said it started being finicky. I'm currently running without the skimmer gate installed. The skimmer gate is just a plastic part that gets placed on the grill to help it only suck water from the top of the water line where you want it. I noticed that as I pushed my pump higher, the water in my display tank rose way to high, almost to the point of overflowing. I luckily caught this in time and removed the skimmer gate. With the gate removed I'm able to push about 600 ish GPH with no issues. The pump I'm using is the one pictured below.

    Once i had my pump dialed in to the GPH I wanted, I turned to working on the water level. The water level I found changes based upon these things: Debris attached to the intake fence (chocking the intake), GPH, water height adjuster, and skimmer gate if you have it installed. Haha all these give you some nice tuning abilities if you take is seriously. Below is the water height adjuster which is underneath the noise reducer cover in the back. Here are some pictures.

    The black piece on the RH side is the noise reducer cover, it helps lower the gurgle sound coming from the unit, but I'm hard of hearing, but my wife tells me it makes a difference.


    Once the noise cover is removed you can look down and see a circle with a rod you can raise and lower. Just so you know it does not screw up or down, wish it did, but it pulls up and pushes down instead. The lower you have it, the lower the water level in your display tank will be (but the more water in your sump there is). The higher it is, the more water in your display tank ( but the lower your water will be in your sump). Once you make your adjustment it happens pretty quickly. It only takes roughly 1 minute of so for everything to change if that. Here is the grill of the unit submerged in water


    For some odd reason I decided to write this review while in the middle of cleaning the sump out. As long as you keep the grill of the box clean, it works like a champ. I've even allowed half of it to get clogged to test it and no major issues happen. I was really surprised at that. Multiple power on and off attempts, pump shut off, dropping the flow all of a sudden, block the outlet, and lots of other stuff I tested the unit with. It remained rock solid during all this. Auto operation as the pump turned on worked like a champion! One thing to note..... I have a danio that is fond of the outflow when its off. For some odd reason he tries he hardest to swim down the tubing. I have found him down in the sump before, not sure if he got sucked in or he flipped out the tank, but I've found him down there twice so far. So if you have smaller fish you might want to be careful.

    Maintenance on the unit is a breeze also, not many areas you have to clean, just 2 major areas and your good to go. I posted it above, but here it is again, the instructions for cleaning the unit.

    [​IMG] [​IMG]

    The line I'm holding above is the venturi line its talking about. Just take a flat head screw driver and it comes off pretty easily. The piping is just like all other piping a little wiggle and pulling take it apart to clean it. Once you have that one rubber hose discoed you can pretty much pull all the internals of the box out, but still leave the outer part of the box connected to your tank for easy cleaning. Thats a massive plus to me.

    - Easy easy easy
    - Self operation
    - Self Priming
    - Auto on and off
    - Quiet operation ( from what my wife tells me)
    - Cheap!
    - Maintenance

    - You might have parts missing.... I've tried contacting the company,but they did not even respond. I was missing hose clamps, but not big issue for me. I had spares
    - 950 GPH, I'm curious how they achieved this, I'm thinking about 800 GPH is about the max for this thing.
    - It's finicky at first, requires you to take the time to tune it for best operation, but setup is quickly.

    Overall i give it an 9/10. This made my experience swapping from a canister to a sump really wonderful. It was way easier than I had planned, and I had thought it required a lot more. I would recommend this to anyone reading this review or if your on the fence about this product


    - Please make sure you put water into the unit before attempting to turn it on. Same goes for the sump, but watch the water level and don't let your pump run dry.
    - Use clamps for a nice water tight seal
    - Dont rush the tuning process, it takes time. Just mess with one item at a time and you'll get it down pat
    - Trying to achieve a higher GPH? Remove the skimmer gate and press the water level adjuster down. I have found that I can hit 700+ with this, but thats about all my pump has with the amount of head its against.
    - Heat is your friend when attaching the tubing. It was a really tight fit for me, heat was required.

    I'll update this review in a couple of months and let you know how its going! O yea one thing [​IMG]

    For those that worry about the gap distance it can cover, so was it, I have a rimless tank. This was able to secure the unit properly and still have distance to spare. Let me know if you have any questions.
  2. ZoFloatTuber569New MemberMember

    What was the price of this unit, who's the manufacturer, what's the product name, & model # ? I've got a 75 gallon tall tank & I've got a 20 gallon long tank that I want to run a sump on. I've been looming looking for a hang over overflow. Any answers would be gladly appreciated. Thanks!
  3. StickyickyoooNew MemberMember

    Above is the link for it,


    Manufactures website,

    All made by kollercraft, they only have one model number of these bad boys. Sorry it took so long to and work and work again. Its $95 on amazon, comes with all the plumbing you need just gotta buy a pump now and you'll be good to go

    Not sure what some of the reviews on Amazon are about, but I've never ran into any problems as long as you can perform the maintenance on the unit all is well.

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