My plumbing setup, please critique

[PaulF757]

This pic tries to show everything. Ran out of 1.5" pipe to extend the drains into the sump. The full siphon is complete, should I add another union below the gate valve to adjust height of the pipe going into the sump since I don't know what the final height will be?

The return line starts at 1.5", to a T, from the T it downsizes to 1" to run the 4 piece manifold. The manifold will be capped off on the left hand side for future expansion, I may even try to run the skimmer if I can from that side, the right side will drain into the fuge with a gate valve to control the flow.
The return continues to a 1.5" gate valve, then a Wye. The wye reduces to 1", from there I will use flex pvc to connect to the 1" returns. The returns are reduced to 3/4" at the top of the tank, two unions before that, then two 3/4" loc line with 3" flare nozzles per side.

Should I add a union on the return between the GV and the wye? It's 1.5" until the wye where it splits into 1".
from the wye I'll use PVC flex to the unions.

[PaulF757]

Pic of return line.

[PaulF757]

Pic of external overflow, BeanAnimal.

[Crusinjimbo]

Paul, recommend your include a rough diagram of your layout. It's a bit tedious to follow all the verbal details and visualize for analysis. IMHO

[Mrramsey]

Paul as long as your drain line is 1/2" to 1" below the top of the baffle it empties into it will be just fine. As for additional unions I always look at it from an adjustment/maintenance perspective. Look at it and ask yourself "if I need to service this can I easily remove it in one piece". If the answer is no then add a union.

Here is a pic of my BA.
uploadfromtaptalk1396785386967.jpg

Its a little dark sorry. You can see where I have unions. I have them on all of my drains since I use 45's it allows me to adjust the position as needed. I can also remove my return pump and the lines to the five and skimmer areas for service or to add additional equipment in the future.