New 350g build plumbing question

[Josepha7697]

Hi All, I am plumbing my new 7’ - 350g aquarium, which contains (2) 30” overflows with 3 holes each for a bean animal setup for each. So I have (4) 1” drains (plus two emergency overflows). reducing down to a single 2” main drain (I only have space fo a single drain to the tank room). Here is the back where the external overflows are

This is the right overflow showing the drain lines (emergency line is in the middle) dumping into the 2” main drain to the sump.

My return pumps are two Iwaki 70s (1536gph x 2 = 3072gph) with two 1” returns splitting to (4) 3/4” lock line returns with duckbills. My question is if I have 4 3/4” returns, will (4) 1” returns reduced down to a 2” main drain be able to handle the draining capacity? I read a 1” pipe can take 2,200 gph, so 2 pipes = 4,400 near peak and a 2” pipe takes 7650gph so it should take it, but not sure about the pressure and if I need to go to a 3” main drain? Let me know your thoughts. Thanks

 

[Big Bosha]

It appears you did your research and are prepared for the journey. However it does seem as though you used schedule 40 joints on the plumbing setup. If you havent already, I would suggest using pvc cement on the joints with quick releases in some areas to ensure there are no leaks. I would be comfortable with it as long as I wasnt running the pipes to their maximum capacity, or really even near their maximum capacity. If your only planning on a turnover rate of 3x to 5x tank volume, then you're only looking at 1,750gph total load on the system. I think you should be absolutely fine. But I'm no plumbing expert, other members on here would be able to tell you more.