RIO Pump mod for Bakpak

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.


Aquarium Advice Freak
Apr 28, 2004
Vine Grove, Ky
I've got a CPR Bakpak 2 skimmer with the RIO pump that came with it. I went ahead and used the RIO pump figuring on replacing it when it messed's starting to. I remember seeing a mod you could do to a MJ600 or so to make it work with the skimmer. I've tried to do a search but couldn't find it for some reason. :roll:
Can someone help me out? Thanks guys.
Found this on another forum.

Travis from [ said:[/url]]
Using these modifications combined, on two separate bakpak skimmers, I have noticeably increased not only the skimming volume but also the darkness of the output. I can honestly say these modifications tripled the skimming ability of my bakpaks.

A. Airline modification

Things you’ll need:
A strong air pump- whisper 800 has worked for me, Tetra Luft pump ($45 from has been highly recommended)
Some airline tubing, about 6’ ought to do it
A wooden airstone
If your air pump has 2 outputs, you’ll need a “T” valve to combine them into one

You should do this modification with the bakpak removed from your tank and emptied of water, as you’ll need to turn it upside down, etc, to get the tubing where you want it.

With the pump side of the bakpak facing you, run the airline down the top of the left (output) side of the skimmer and under the plastic divider. You then want to pull the tubing to the top of the right side so you can attach the wooden airstone. Then pull the tubing back through the output side of the skimmer until the wooden airstone is about halfway up the right (output) side. A straightened coat hangar can help push the airline tubing down where you want it throughout this modification process.

Connect the tubing to your airpump, put the skimmer back on the tank and run the air pump after the bakpak fills up. VOILA! You have now seriously increased the production of your bakpak. You may need to adjust the height of the collection cup, as the water level will be significantly higher with this modification. Assuming your venturi was properly set before doing this mod, it will probably require no changing. It’s recommended you change the wooden airston about once per month or when skimming drops off. Be ready to change your collection cup more frequently, especially the first few days after you do this modification, as it’s pulling out a “backlog” of organics the regular bakpak couldn’t necessarily keep up with.

There are other ways to do this modification, but they involve drilling. This is the easiest and most convenient way, but you can also drill a hole in the top of the collection cup and run the tubing down into the reacton chamber that way, or some people have drilled the right side of the skimmer above the water line and added an airline hose “nipple”.

I recommend doing it the easy way first and if you’re happy with it, you can always drill your bakpak later and get the same (not necessarily better) effects.

B. Maxi-jet modification

If you have done the airline modification, I recommend a maxi-jet 1200. If not, a maxi-jet 900 may be a better choice. Simply purchase the maxi-jet pump and the “turbo venture kit” (4.99 at Follow the instructions on the venturi kit, and attach the maxi-jet where the rio used to be. This may require a very small section of larger airline tubing to connect the maxi-jet to the skimmer. If anyone knows the appropriate size tubing to use, please let me know and I’ll add it here. My guess is ½” but the safest thing to do is bring the maxi-jet to the store with you.

The maxi-jet upgrade without the airline modification mostly just replaces a questionale pump with a good one. Rios are known for failure and, even worse, putting stray voltage into your tank. They may also “melt down” with disastrous effects.

When coupled with the airline modification, the MJ1200 will help your skimmer move even more water, resulting in better skimming and water movement.

Top Bottom