A built-in overflow is the most efficient method of draining aquarium water to a filter. If your aquarium does not have built-in overflow, CPR Continuous Siphon Overflows/Prefilters are the best means for getting water from an aquarium to a filter system. They quietly skim up to six times more water than units with tubes.
The advantages of CPR Continuous Siphon Overflows/Prefilters include:
- Adjustable water level allows you to easily change the level in your tank
- Black top reduces algae growth
- Plastic screen to prevent fish loss
- Quiet operation: All units except the CS150 come with slip screen, sponge and vent tube to help reduce noise.
All Deluxe CPR CS Overflows come with the Aqualifter Pump and acrylic lid for quieter operation.
CPR Continuous Siphon Overflows are used to transport water from the tank to your sump. Deluxe models include the aqua lifter to help maintain a full siphon.
- Flow Rate: 300gph
- Outflow Size: 3/4" Bulkhead
- Width: 6"
- Dimensions (see photo): A: 6.5", B: 7.5", C: 1.5", D:1.25", E: 3 7/8" , F: 4.75", G: 7.25", H: 5.5", I: 3.5", J: 2.75", K: 3"
Good Product By Choosen One on 4/23/2018Choosen One would recommend this product to a friendI've had mine for 2 months now and haven't had any issues. The quality is good. Everything fits together snug. 3 adjustment screws. 2 to set the height you want and 1 to level the box on the back of the tank. The high flow sponge filter works good. No problems with it clogging up. The only downfall is trying to clean algae from the inner walls. A variety of flexible brush does help but still can't reach everything.
some major flaws By John on 7/11/2016John wouldn't recommend this product to a friend4 months ago I switched around my reef tank and fresh water tank so my reef had more room. This required a replacement external overflow box. I bought the CS102 and ran it at 50% the rated capacity.
The initial concern was that the internal box was clear (unlike my old one which was black) and it now grows algae inside the over flow which is annoying to clean. It is fairly quiet at 50%, but slightly annoying if you increase the flow rate to 80% of capacity.
The major issue I have with it is its internal box design. The depth of the box is way too shallow. This causes (even at 50%) air bubbles to flow under the divide and into the siphon. This isn't a big deal since the aqualifter is constantly pumping out the accumulated air. What make me mad is the rate at which this occurs. If the aqualifter stops removing air for any reason, the air will accumulate and break the siphon in a matter of hours. Adjusting the tilt of the unit does not help much. After 4 months the aqualifter got partially plugged and the siphon was on track to break. Luckily I was home and noticed and corrected the problem. I have it set so a siphon break will not over flow the tank, but of course my pump will be sucking air. If the unit was designed better (deeper internal box to allow bubbles to raise to surface instead into siphon) then this siphon breaking process would take days/weeks instead of hours. I have ran an external overflow box for 20+ years and only once came close to an over flow (on vacation) because the unit was designed well.
This unit may be the best of what is available, but it sure is a downgrade from 20 years ago. If you must purchase an external over flow, make dang sure you have back up plans in place to deal with a failure of the unit. It will happen. In 30+ years of fish keeping, this unit makes me really nervous and will be replaced.
Works great By KLMulder on 5/9/2016KLMulder would recommend this product to a friendQuick and easy install on my 180Gal salt water tank. Trouble free operation. Lost power the day after getting the tank up and running, when the power came back on the pump removed the air from the overflow and had it working perfectly again before I had even checked on it. A+.
Using on planted tank By jcdelaroche on 4/24/2016jcdelaroche would recommend this product to a friendWorks great, quiet and of excellent build quality.
it works great drawing the surface scum, keeps my water clean. I'm using it with an Aqueon pro flex model one and I'm overall very satisfied with this
Product. I have used it for a few months, I use the aqualifter pump to removed trapped air.
Near silent with tweaks By Jason on 4/22/2016Jason would recommend this product to a friendI purchased the CS102 because it has 2 1" drains. I didn't need the 1200 gph capacity, but wanted to set it up with a "modified" Bean Animal design for quieter operation. My 55 gallon tank is tempered, so drilling isn't an option and I can't afford to upgrade yet. Previously I had an Eshopps overflow with a single drain. This worked, but I could never make it quiet. Since the tank is in the living room, this was a constant annoyance. I decided to go with a Bean Animal type setup as best I could with a HOB overflow. I know I should have a third drain to be completely fail-safe like the true Bean Animal design, but I'm willing to take the risk for now. I made one drain a full siphon with 1" PVC elbows and made the height near the bottom of the drain box. The other drain, I extended so that it is just below the water height in the tank. I then used a gate valve to dial down the flow of the full-siphon drain so that the water level is just even with the open, drain. I have a controllable DC pump, so I was able to optimize the flow rate and match this with the drain rate to make it all completely silent. Now I only hear an occasional trickle as my Gyre pump causes a slight surge as it cycles on.
Great Product! By Joshua on 3/3/2016Joshua would recommend this product to a friendCS90 (600 gph) works very well, easy to install. Great build quality!! I have abandoned the filter foam on the bulkhead strainer because it clogs (shrimp shells) too easy and must be cleaned every 2 days. Seems to run quieter without it. I have it matched with a 714 gph return pump & it seems like it could take more flow. Great option if you don't want to drill your tank.
Very nice By Dimitri on 2/25/2016Dimitri would recommend this product to a friendI will never be 100% OK knowing is not an internal overflow box. Any way this works fine it has never fail- a few times I had a power failure and everything started working right on time. I bought 2 I like it I do think is pricey but nothing is cheap in this freaking Hobby ha ha ha I will recommend it.
Super happy, nice piece of equipment! By Landon on 1/3/2016Landon would recommend this product to a friendI was able to get it running quickly and I am very happy with the overall quality of the product. It runs quietly and is secured firmly to my rimmed 55 gallon tank. The small pump included is very quiet as well and I was able to splice it's input to also prime a water bridge I have on my sump!
My only issue is that the priming air nozzle coming out of the top is very delicate and positioned vertically. I have my tube running down and I feared I might break it from snagging the tube at some point so I worked around this by using a short piece of tube up and then to a 90 degree irrigation elbow which led my tubing over and down to my sump, where I have the pump stashed. I also attached a zip tie anchor to the side of the overflow container and secured the tube to the side in order to prevent it from tugging the delicate nozzle. This seemed like a better connection and reduced the risk of it breaking off the nozzle which could lead to a serious issue! I also zip tied my tube onto the nozzle as a last precaution.
Other than that, I am super happy with this purchase and it is running beautifully.
Good product By Jeff on 11/17/2015Jeff would recommend this product to a friendDoes as advertised. Added an additional bulkhead and overflow to balance the overflow and to prevent the unit from pulling a siphon and making that annoying flushing sound.
Awesome By Bogey on 8/18/2015Bogey would recommend this product to a friendWorks just like is says! Great shipping got it faster then they said! Will buy more stuff from them!!
Great product but beware of over flowing syphon By GP on 7/28/2015GP would recommend this product to a friendDo not get it with out the pump or you are increasing chances of syphon failure. Even with pump it may happen so invest in a new tank or get an apex controller with relay floats to control return pump in case of over flow.
Great Product By Luke on 7/11/2015Luke would recommend this product to a friendStraight out of the box, it was quick and simple to install on the tank. I did not want to drill my tank and this fit the bill perfectly. I did do a little oversized on it to get better flow rates and additional protection, and this overflow delivers!
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What is a good return pump to pair with the cpr cs50
The CS50 is rated for a maximum of 300gph of flow, so a pump that will deliver within this range would be necessary. Something like the Sicce 1.5 or 2.0, depending on your head height, would likely be a good option for a return pump.
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