Hi I am going to be picking up my new tank this weekend

So I think I have finally came up with a sump design for my tank. I have spent a while trying to see what others have done with there lido 120's Not a tank you get in America I think. (Im in the UK)

Well anyway I am going to get my tank drilled and somehow get a overflow box made and find a small tank that will fir my stand. Heres a diagram I drew. Will this work, should I change anything or have I forgotten anything?

Click to view attachment

So my thought was. I would have an over flowbox for surface skimming, then with a durso stand pipe that comes through a 1" bulkhead down the back of the tank. I put a gate valve on the line in to stop water flow if need be. Then it goes into the 1st chamber of the sump, then over the baffles to chamber two where the heater and cheato is. Then into chamber three where the return pump goes up and splits and returns to the tank through two smaller bulk heads (1/2"?)

Still don't know the exact sizes and diameters of all the pipes and holes.

Thanks for any help and advice

That will work fine. Just do the head height calculation for the return pump.

To make the drain line get the following:
1 x T fitting
3 x Union fitting
1 x cap
1 x gate valve
1 x ball valve
1 x 90' Street L
1 x bulkhead fitting

It goes together like this:
90' L ---> bulkead ---> union ---> T fitting ---> ball valve ---> union ---> pipe ----> union ----> transition to hose ----> gate valve

This way you can pull apart or swap out different sections of the drain to clean it or repair it without having to drain the tank. Use all 1" fittings.

On the return:
8 x union fittings
1 x wyse fitting
1 x gate valve
6 x ball valves
2 x 90' street L
2 x bulkeads
1 x 4 way
2 x 3/4" to 1/2" reducer
From the back of the tank down:
dry side of bulkhead --->reducer bushing--->union ---> Street L ---> union ---> ball valve ---> hose ---> union ---> ball valve ---> wyse fitting ---> union ----> gate valve---> 4 way fitting with a ball valve on each open end ----> hose ----> union ---> output from pump

Again this way you can dial in return flow as well as pull one section off line while the other section continues to run and detach the pump from the whole assembly easily. Use 3/4" right up until the return line and reduce it at that point as well as at the pump fitting. The reason for this is that it allows you to use a bigger pump down the road if you need it. The 4 way allows you to attach things like a chiller or reactor and plumb it off the main pump.

Personally I prefer to use slip fittings to cut back on salt creep and for a better seal except at the bulkheads where I use threaded. You may find that threaded with plumber's tape works better for you.

Wow thanks very much.

Thats the exact info I was looking for. Thats a good idea to put those extra ball valves in never thought of that. My take a while for it to make 100% sense in my head but I should be able to go ahead with that. Looks like I shall be taking a trip to the Diy store soon

Can't Wait to get this up and running.