Protein Skimmer Air Filter DIY

There are many stories on the aquarium forums of people having tank crashes due to a potential toxin in the air from drywall dust, paint or household cleaning products.  This can happen because your protein skimmer is injecting air into your saltwater aquarium.  This DIY shows a simple protein skimmer air filter that can help prevent toxic gases from entering the aquarium. Another use is if you want to inject fresh air from outside in the tank to help an aquarium with low ph due to high CO2 levels.  

Supplies Needed: 

1/2” and 1” pvc pipe
1/2” pvc elbow
Mesh bag and aquarium carbon
3/8” ID vinyl hose
1/2” to 1” PVC slip adapter
Hose barb 3/8” to 1/2” threaded PVC
1” PVC slip cap
1/2” slip to threaded coupler
1” slip coupler 


 This shows the overall way it is to be assembled.
Cut a short length of 1/2” PVC and attach it to the 1/2” elbow and 1/2” to 1” reducer bushing.  I did not use glue but you can glue this together if you like.
Then attach the 1” coupler.  Again glue is optional.
Cut a piece of 1” PVC about 4-5” inches long.  This will act as the area that the carbon bag will fit. The longer the area the more carbon you can fit.
Place the mesh bag into the 1” PVC pipe and fill the bag with carbon.  Close the bag and stuff the rest of the bag into the pipe.
Drill a bunch of holes into the 1” cap so you can allow air to flow through the filter.  Then install the cap onto the 1” PVC pipe.  Do not glue this piece as you will want to remove it to change the carbon every couple of months.


Here is the completed assembly.  From this point on how you attach it to your protein skimmer depends on the skimmer you have and where you want to locate the filter.  This portion you will need to figure out. The next steps is what I did to attach it to my ASM skimmer and put the skimmer air filter in the garage.





I cut a piece of 1/2” PVC about 18” long.  I put a 1/2” threaded to slip coupler  on the PVC.  I then attached a 1/2” to 3/8” ID hose barb to the coupler.  A hole was then drilled in my floor board going out to the garage.  The air filter was put into the garage to I can pump fresh air into the skimmer but it would be protected from the outdoors.  










Here is the assembly through the floor board into the garage.  I then ran the vinyl hose to the hose barb and connected the other end to the protein skimmer.
I then slipped the vinyl hose over the skimmer air line.  This completed the DIY.  It has worked very well so far and was inexpensive to do.  I have seen some improvement in my PH since the installation.