Internal sump filter

hello guys, once again i need your knowledge and advice
but first, some context:
i have a cichlid tank with jewels, convicts, jack dempseys and green terrors
i recently build and internal canister, using: pvc tube, powerhead, sponges, bio balls and lava rock, and it worked great
but now i want to improve the filtration as they are growing bigger and producing more waste, and also because i want something new, improve my experience

so the deal is, i want to create this internal sump, but i want it to collect the water from bellow, as you can see on the first chamber
in this first chamber i will put sponges and on top i'll place the powerhead, that will suck the water from from the main tank through the sponges, and dump it on the second chamber
the second changer will have filter floss, and the third chamber bio balls and lava rock

does this make sense or there is some mistake?

ps: i don't have experience with sump filter

 

+1 for internal sumps. I run these on all my tanks larger than 100 gallons. Change the floss once a week, bang out the sponges every few weeks and kick back and relax. Great system

 

+1 for internal sumps. I run these on all my tanks larger than 100 gallons. Change the floss once a week, bang out the sponges every few weeks and kick back and relax. Great system

so by your experience do you feel it will work the way i have it planned? or should i place the powerhead on the last chamber?
any advice is welcome

 

so by your experience do you feel it will work the way i have it planned? or should i place the powerhead on the last chamber?
any advice is welcome

I run the powerhead/lift tube from the last chamber

 

I see one problem: if the tank water level falls below the first divider, the water flow from the intake will stop

 

I see one problem: if the tank water level falls below the first divider, the water flow from the intake will stop

ok, but i will not happen, the tank is 50 centimeters high (the tank is 100 x 50 x 50 cm), i'm planning to make the sump 30 cm high (30 x 30 x 10 cm)

another question: do i need to place some "holder" to keep the medias from blocking the bottom!?
like in this picture:

 

couple more questions:
1 - should the input be on top, or is ok if i left it on the bottom?
2 - is there a standard or minimum size for the chambers?
3 - is there a minimum distance for the two pieces of glass that separates the chambers?
4 - does the chamber with deep sand bed for denitrification makes sense?

hope someone can help, it has been difficult to find the very basics about internal sumps.