JohnV8r
New member
I wanted to provide some photos of my ASM G-3 Recirc Mod to help fill in some gaps in the information that exists at this time. First, let me start by saying that this is a VERY EASY mod to make if you plan it out and don't just decide to do it on the fly one morning.
Without a doubt, the scariest part of doing this mod for most people will be the notion that you are going to cut into your skimmer. You have to cut holes to accommodate putting the pump intake into the skimmer and to allow for a new water intake. Both of these should be done by using a hole saw. These are pre-made round cutting tools that can be purchased at Home Depot for about $7 each. You will need two to do what I did; a 1" and 1.75" hole saw. These fit in a drill and allow you to cut an easy circular hole in the body of your skimmer.
The hole saw in the picture above is the 1.75". The trick to using hole saws successfully on plexiglass or PVC is to drill the pilot hole, then reverse the direction of the drill so that the hole saw it going backwards. This prevents the teeth from making too aggressive of a bite that can cause cracking. Take your time and don't push to hard. It's easy if you're patient.
You will have to line up the pump intake directly underneath the factory drilled hole. I used a Sharpie to trace around the venturi and put the pilot drill bit right in the middle of the circle I traced.
This is the ASM bulkhead. It requires a 1.75" hole to fit properly, hence the 1.75" hole saw. I bought this extra bulkhead from Aquacave.com . Taking the time to get an extra bulkhead is worth the wait. It makes the recirc mod much simpler than the belt sanded PVC intake solutions I found in other posts.
Once the hole is cut and bulkhead fit in place, you simply need one 1" 90 degree elbow to put on top of the Sedra pump, a section of 1" PVC, another 1" 90 degree elbow to direct the flow down, and another section of 1" PVC to take it to the bottom of the skimmer body.
This is what it looks like assembled:
No glue needed to complete any of the recirculating pump parts. Just push them together firmly.
Next you will need to use a 1" hole saw to cut the intake hole. Again, drill the pilot hole and reverse the drill direction so the hole saw cuts backwards. Parts are found in Home Depot's plumbing department where the sprinkler and drip system materials are found. Toro makes the black PVC female 90 degree fitting and the male 90 degree fitting. All you see in the pictures are the female 90 degree piece here.
Once the hole for the intake is cut, I dry fitted the 90 degree female piece and then glued it in place using PVC cement. I used Christy's Red Hot Blue Glue PVC cement. I like Christy's Red Hot because it is a one step (no primer needed) cement and it is made for pressurized systems. I put a layer of PVC cement on the 90 degree fitting, held it in place until it bonded (30 seconds), and then used an old Elos test kit syringe to put a bead of cement on the inside seam (inside of the skimmer body). That helped to seal any gaps in around the fitting and ended up looking like this:
Next, I used 3M 5200 Fast Cure Marine Adhesive Sealant to create a bead around the 90 degree fitting on the outside of the skimmer body. 5200 is easy to use and works fantastic as both an adhesive and a sealant. Some people are squeamish about the zinc oxide in 5200, but IME once cured it doesn't leach out. In this instance it's on the outside of the skimmer body anyway and won't contact any water. When finished, it looks like this:
This whole modification took me about an hour to complete (plus cure times for the PVC cement and 5200 Adhesive).
I did not put the "bubble cup" in the bottom of my skimmer as described in this G3 mod: http://www.talkingreef.com/forums/diy-projects/2001-my-uber-skimmer-asm-g-3-modification.html
I hope this helps the next person contemplating the ASM recirc mod. My G3 has the Gate Valve mod, the Mesh Mod, and now the Recirc Mod. I'm very pleased with its performance on my 194 gallon system.
If anyone has any questions, I am subscribed to this post. Just reply with your question and I will respond.
Without a doubt, the scariest part of doing this mod for most people will be the notion that you are going to cut into your skimmer. You have to cut holes to accommodate putting the pump intake into the skimmer and to allow for a new water intake. Both of these should be done by using a hole saw. These are pre-made round cutting tools that can be purchased at Home Depot for about $7 each. You will need two to do what I did; a 1" and 1.75" hole saw. These fit in a drill and allow you to cut an easy circular hole in the body of your skimmer.
The hole saw in the picture above is the 1.75". The trick to using hole saws successfully on plexiglass or PVC is to drill the pilot hole, then reverse the direction of the drill so that the hole saw it going backwards. This prevents the teeth from making too aggressive of a bite that can cause cracking. Take your time and don't push to hard. It's easy if you're patient.
You will have to line up the pump intake directly underneath the factory drilled hole. I used a Sharpie to trace around the venturi and put the pilot drill bit right in the middle of the circle I traced.
This is the ASM bulkhead. It requires a 1.75" hole to fit properly, hence the 1.75" hole saw. I bought this extra bulkhead from Aquacave.com . Taking the time to get an extra bulkhead is worth the wait. It makes the recirc mod much simpler than the belt sanded PVC intake solutions I found in other posts.
Once the hole is cut and bulkhead fit in place, you simply need one 1" 90 degree elbow to put on top of the Sedra pump, a section of 1" PVC, another 1" 90 degree elbow to direct the flow down, and another section of 1" PVC to take it to the bottom of the skimmer body.
This is what it looks like assembled:
No glue needed to complete any of the recirculating pump parts. Just push them together firmly.
Next you will need to use a 1" hole saw to cut the intake hole. Again, drill the pilot hole and reverse the drill direction so the hole saw cuts backwards. Parts are found in Home Depot's plumbing department where the sprinkler and drip system materials are found. Toro makes the black PVC female 90 degree fitting and the male 90 degree fitting. All you see in the pictures are the female 90 degree piece here.
Once the hole for the intake is cut, I dry fitted the 90 degree female piece and then glued it in place using PVC cement. I used Christy's Red Hot Blue Glue PVC cement. I like Christy's Red Hot because it is a one step (no primer needed) cement and it is made for pressurized systems. I put a layer of PVC cement on the 90 degree fitting, held it in place until it bonded (30 seconds), and then used an old Elos test kit syringe to put a bead of cement on the inside seam (inside of the skimmer body). That helped to seal any gaps in around the fitting and ended up looking like this:
Next, I used 3M 5200 Fast Cure Marine Adhesive Sealant to create a bead around the 90 degree fitting on the outside of the skimmer body. 5200 is easy to use and works fantastic as both an adhesive and a sealant. Some people are squeamish about the zinc oxide in 5200, but IME once cured it doesn't leach out. In this instance it's on the outside of the skimmer body anyway and won't contact any water. When finished, it looks like this:
This whole modification took me about an hour to complete (plus cure times for the PVC cement and 5200 Adhesive).
I did not put the "bubble cup" in the bottom of my skimmer as described in this G3 mod: http://www.talkingreef.com/forums/diy-projects/2001-my-uber-skimmer-asm-g-3-modification.html
I hope this helps the next person contemplating the ASM recirc mod. My G3 has the Gate Valve mod, the Mesh Mod, and now the Recirc Mod. I'm very pleased with its performance on my 194 gallon system.
If anyone has any questions, I am subscribed to this post. Just reply with your question and I will respond.
