Pipe for bottom drain (3" vs 4")

[jclements]

So we glued together a bunch of 4" PVC for our bottom drains this weekend. Essentially all glued joints failed. We think it's because the schedule 40 pipe diameter is just a little too small. Moving on. We decided to buy some 4" flex PVC to try to simplify things. A 50' roll is pretty reasonable from the online retailer we use; however, they are out of 4" pipe and the distributor is not going to have stock available until the spring. We have plenty of 3" flex PVC on hand. Would it be too much of a compromise to use 3" flex PVC instead of standard 4" PVC?

[tranquility]

We used 4" pvc..had no problems...(maybe I should say yet)...I really don't think it would make much of a difference going down to 3" as long as you have plenty of pull from the pump.....I've noticed that with even my 2" pipes in the old pond--as long as I keep a larger pump in the tank that was pulling thru the pipes they didn't stop up...but, a smaller pump and I had to unclog pipes a couple times during the summer months....
Lawanna

[Michiponder]

I have used both 3" and 4" bottom drains.  The first pond I put in where I live now was put in 16 years ago (bout 1600 gal.) and has 3" piping.  It has proven to be a real pain in the butt by clogging with leaves and other debri.  Ponds built here later all have 4"  drains and rarely clog even with the heavy leaf drop in fall.  Maybe with the right locataion or drain cover the problem with the 3" would not be so bad.

[tranquility]

another thing I'm doing now to make sure I have no clogs is closing off each bd for about an hour or so each week before I clean out the filters--that way I'm pulling all 4,200 gph thru one pipe...I saw quite a bit of poo and leaves  gush out of the pipe and into the filter when I did it and my new pond is only a week old...
Lawanna