[rsman]

Now can you all help on this so I get this right. ok i guess its better to ask now then to have a problem later

Now as I read 3" x 24" pvc pipe is all the size it needs to be with bioballs inside.make it as big as you need to to keep the coil easy to manage
And 50' of .170 ID coil put on the inside of pvc pipe so it will not get light.
Or as I saw coils on the outside is that ok now?
light = bad just for different reasons in different areas of your unit. light on the coil will cause algae growth which will clog the coils and add oxygen which will make the coil inefficient. light in the bio chamber will kill the anerobic bacteria also bad. having the coil on the outside just means that you dont want a lot of light on the coil it dosnt need to be completely dark always. if you think you might need to expand your unit put the coil on the outside its easier to add to the outside than the inside


As I reading 50' is ok not 75' too long for size of ID?true

If more load add coils of same size beside each other with two valves on each end for flow not two or three coils put together inline? yes they need to be in parallel not in series. if you have 2 or more coils then having an adjusting valve AND a cutoff valve per coil makes it easier to adjust as you can cut off the flow to all but 1 coil at a time, and the unit output will be the same as the coil flow its not a requirement its just easier that way

Also the tee from a pump for water supply. until you get HUGE gravity works
[/b]valve on outlet to set timing.[/b] or input
Timing as:
Alot of nitrite speed up slowly and wait
Alot of nitrate slow down slowly. and wait.

sounds good to me