Before I touch this, let me check

Got my new to me (used) 90 gallon with overflow today. It has an overflow which I never had before. Below is a pic of a cap on the underside of the tank.




Can I Un-screw this to clean? I assume I'm going to have to undo it anyway to fab in the new pvc to go into the refugium anyway right?

Thanks! Here's some more pics of her. I have to clean it good outside when it gets warmer. A lot of caked on stuff...



And

Thanks guys! Researching the plumbing tonight, never had a refugium, so this is a first.

 

That tank has seen better days! Looks just like the outlet to the stand pipe. I would definitely remove it and replace it. Don't want old PVC.

 

Would u recommend just soap and water to clean it? I hit it with a wet rag before, it looked worse lol but some junk is really in there

 

The 1" pipe comes out. The top and bottom connector looks like it's silicones there for life.. Although I'm sure there's a special wrench I need to take it off. For now I'll just replace the 1" pipe but the outlet idk if I want to touch.

Also I don't know how you would be able to attach another down pipe in there, there's no space for it to sit flush unless I did some rigging. But then again I never did this before.





Top view after taking out 1" pipe

 

The silicone will come off and the bulkhead will unscrew. Read my Bulkhead Installation Tips sticky post for ideas on how to prep and plumb a new one without the silicone for a leak free system.

For cleaning get a gallon jug of distilled white vinegar at the grocery for about $2, lay the tank on its back, front or side, soak an old bacth towel or some rags in the undiluted vinegar and drape it over the area you want cleaned. Keep the towel wetted and the build up should soak right off in an hour or two with little scraping or scrubbing. Turn the tank to a different side and do it again until it is all clean.

 

Perfect! Thanks -

And I got the bullhead off. I think it's a 1 inch because the hole is like 1 1/2". So I ordered a schedule 80 head.

Should I go standard , double threaded, or slip on?

 

If the hole is 1.5" a 1" schedule 80 probably won't fit, check the charts at glass holes to make sure.
If you read my sticky thread you will find I always recommend thread x thread bulkheads. Take the little extra time to clean and prep the surfaces and threads and it will pay off. I also recommend the PVC thread sealants as do the PVC manufacturers and not teflon tape or silicone.

 

A standard 1" bulkhead requires a 1.75" hole so a Sch 80 would be over 2". A 1.5" hole size is a standard 3/4" bulkhead.

 

Just read ir, very cool! Ill put the link if here if anyone else needs it.
http://www.3reef.com/threads/bulkhead-installation-tips.111422/

So, im 90% sure i have a 1" schedule 40 bulkhead, Therefore i would need a 3/4" schedule 80. HOWEVER, do i lose anything reducing the size for the reliability of the sch 80? or should i just go with the original 1" size again?

3/4” ABS Bulkhead - 34mm/1.33" (Installation Hole Size) 1 3/8"
1” ABS Bulkhead - 42mm/1.65" (Installation Hole Size) 1 3/4"

3/4” SCH 80 Bulkhead - 41mm/1.61" (Installation hole size) 1 3/4"
1” SCH 80 Bulkhead - 48mm/1.88" (Installation hole size) 2"

 

Excellent advice from AZDR,

I"d go with the same type bulkhead it had. It's not a high tensile area, it simply allows you to have a sealed hole in the tank to plumb thru.
If it's RR, I thought there should be 2 holes drilled thru already?

And don't go smaller diameter pipe for the drain,