Modified CPR overflow with pics

I know most of you have reef ready tanks that are drilled but I started with fresh water then converted using a CPR overflow. On one of the other forums there is a long thread about the "herbie" mod on drilled tanks to quiet the bubbles and splash in the sump. Decided to give it a try on the CPR even though one post said it wouldn't work on an overflow. Well, it worked perfect and is simple to do.

1. Drill the overflow and install a second bulkhead. Mine are 1". You can by a CPR with a second bulkhead already installed.

2. Inside the CPR, install a 6" pipe and finish by running the rest of the pipe from the bottom of the second bulkhead to the sump. This serves as an emergency drain incase the main drain ever clogs. It will make a good amount of noise when water runs down it so you know something is wrong. I also tested it by blocking the main drain completely and it worked perfect by preventing the CPR from overflowing.

3. Install a gate valve at the bottom of the main drain in the sump. Slowly close down on the valve until the water is high enough in the CPR to prevent it sucking air, but slightly lower than the top of the emergency drain. Use a gate valve instead of a ball valve as they are more precise.

That's about it. No more bubbling and splashing noise in the sump. Water level in the CPR is staying pretty steady, not varying more than 3/4". And now I have an emergency drain so I don't have to worry about the CPR ever overflowing.

One other mod I did is spray paint the exposed underwater side of the CPR black. With my black background the CPR virtually disappears. In the full shot, the CPR is in the upper right corner. I have the light shifted to the front of the tank so the back of the tank is naturally darker so that helps, too.

 

Very cool tip! Your tank looks good.

 

That is an awesome idea. I wish I still had my Hang on overflow to try that out.

 

perfect timing... im ordering a cpr overflow for my 20gal mantis tank im adding to my existing system. nice having that second redundant return pipe in the event the main gets stuck.

i do have a question a little offtopic. how do you like the CPR overflow overall? have you had any issues with it during power outages? do you use the lifter pump thats like $15 extra to help maintain siphon?

thanks, and the tanks looking great!

 

Absolutely no problems with it. Get the lifter pump. Mine came packaged with it and a lid for the CPR. I wouldn't run the overflow without the pump to keep any air from messing up the siphon. Also, with a power outage, the lifter pump will automatically get things going again. The next mod I'm going to do is install a second nipple on top of the overflow and probably a second lifter pump incase anything happens to the first. That will make it disaster proof I think. I read where one guy had a bug fall in the tank and end up blocking the nipple causing a spill.

Thanks for the comments. Just getting the tank started. All of the fish are in quarantine at the moment. Just have some frags in there right now. .

 

thanks k+