Most of the reef tank and aquarium lovers completely understand the importance of an overflow box. The prime advantage of utilizing an overflow box is that it makes sure that your display tank consistently maintains the optimal level of water all time.
To replenish evaporated water in an effective manner, overflow tank properly pumps in the optimal level of water quickly after sensing the low level of water in a tank. To remove the impurities, it also pumps aquarium water through a filter.
Categories of Overflow Boxes
Overflow boxes are available in two distinctive types which are internal and external.
In most of the cases, the internal version is considered as the best option. It is very easy to customize and the best part is that it is very economical as compared to the external version. It can be easily placed inside the tank and you can also cover it with a cabinet. But for doing all these things, your main aquarium tanks should have a drilled hole.
On the other hand, the external version would be a better choice if your aquarium does not come with predrilled holes. Though, you can also drill holes on your own but it’s quite a troublesome task for anyone to do it with utmost perfection.
In addition, if there is not much extra space below your reef tank then also external version would work better. It basically acts as a HOB (hang on back) unit. You can easily hang it at the back and to hide it, use your tank decors such as coral.
Moreover, there is no requirement of a drill as well because they can easily suck the water over the side of tank with the use of siphon. The only disadvantage of this is that sometimes the air enters the siphon and thus water stops draining to the tank. This will eventually lead to the overflow of water as the pump continues to through back water in the aquarium.
Thus it is highly important to check that whether the overflow can draw out air or not.
Thus, it is very easy to keep track of the quantity of water which is inside because an overflow box gives a clear view.
Purchasing a Hang-On Overflow Box
You can accurately decide which HOB overflow box will work great for your aquarium by using many different ways. In most of the cases, the manufacturer gives complete information about the selection of right aquarium size according to overflow box.
Another most important thing that you must consider is the right level of the overflow box flow rate. It should be rated quite higher than the return pump flow rate.
This means you can utilize a 600gph if you own a 500gph return pump. The simple method to make the right selection is to check the exact size of your tank and multiply it by 10. It means if you have a 90-gallon tank then 900gph is optimal.
In other words, it is perfectly fine to use a bigger overflow tank that offers a high flow rate. This is because the overflow can accurately regulate itself and it will also restrict the pumping of excess water than the amount that needs to flow into it.
However, buying a larger overflow box will be quite costly for you as you are paying for greater capacity.
Other main factors that you should consider are:
The main thing is that it is all up to your understanding and choice to get the wet/dry filters, sump, refugium that you want for your tank.
Best 4 Super Sleek Hang-on Overflow Boxes
1. Eshopps Overflow Box
Mainly, here we are discussing the PF-800 overflow box, which is considered as the optimal box for 75 to 125-gallon aquariums as recommended by Eshopps.
The dimensions of this box are 8 by 3 by 10 inches that simply means that there is the need of 3 inches of space between the tank and the wall.
This basically contains the U-tube siphon, pre-filter box, cylinder foams, and other essential items such as wing nuts and nylon screw.
2. Aqueon Hang-On Overflow Box
This overflow box is basically for 125-gallon tank but the company also offers a 400-gallon version of this box.
It is very difficult to do proper and deep research on this as the Aqueon doesn’t provide any detailed description of its features even on its own official website. The only information that it gives is its dimensions which are 8.3" x 6.3" x 11.5".
Moreover, its design does seem to offer an easy and quick setup as it basically made with a dual drain design. The best thing about this box is that if the drains get clogged, it can handle quite a bit of water.
3. KollerCraft TOM RP3 Overflow Box
The dimensions of this overflow box are 8 by 7.5 by 6.5 inches (LHW). It is perfect to use for tank frames of maximum 1.75 inches thickness. It’s also rated for 800 gph pumps.
Moreover, its gravity system primes without any external efforts and specifically in an automatic way. To prevent excessive overflow of water, it also contains an anti-siphon feature.
4. CPR CS90 Overflow Box
This model of overflow box offers 600gph overflow rate and rated for 125-gallon tanks as well. It also provides a quite simple way to adjust the level of water and to prevent the growth of algae; it also contains a black top.
In my opinion, all these different types of overflow box work in a proper and effective manner. But if we look for optimal consistency level, then CPR CS90 works great but only if you use the Aqua Lifter pump to with it.
Moreover, it has also received the best reviews from many people. There is hardly any case where you hear about the failure and missing pieces of this box.
Feel free to share your thoughts, submit your questions, and give your valuable recommendations to us.