Looking at my system

[Burton]

Finally going to start getting the tanks together ... finances are not perfect but getting better so hopefully in a month I can have it up and cycling. (being realistic here)

My general numbers used for questions / concerns below:

• 300g stock tank filled with about 240 gallons of water (4" gap at top)
• 275 IBC split in 2 as GB's filled with 16" hydroton (110 gallons of hydroton in each half and 96-103gallons of water displaced when both are filled + hydroton with a 2"-1" dry gap)
• sump tank 100g (probably 2 50's linked since they are smaller in size) 

 Concerns:

1. Generally you want a 1:1 ratio of GB : FT with this setup I would have a 220 : 240 or if you include the sump 220 : 340ish 
   
   Does this mean I will need another bio-filter like a MBF in the mix? I plan on using goldfish since I dont eat fish and dont want to deal with the FDA in selling fish locally. 
   
    
2. Which way should I split the IBC 40x48x46 (I assume the real dimensions of the plastic insert to be 40x48x40 LWH)
   
   If I split it vertically down the front and sacrifice the 6" from center to remove the valve + bung then I am left with two halves roughly 48x40x17. How could the stock cage support this as two sides wouldn't have metal supports.
   
   If I split it vertically down the side I would end up with one tank holding more than the other because of the front valve and the dimensions would be 21x40x40 (note only filling up to 16" hydroton)  How could the stock cage support this as two sides wouldn't have metal supports.
   
   If I split it horizontally then I have a bung on one side and a valve on the other so they might vary a little on the water / hydroton in each with dimensions up to 48x40x20. This would be odd as well as the cage on one half would require support where it was cut. And the cage on the bottom half, having the pallet section with assumed 6" height, would sit higher than the other GB. (This could be solved by making this GB brick supports 6" smaller.
    
3. I plan on putting the GB's on bricks to better slide the sumps under and use gravity. The FT is only 20" tall with a drain at 16" into the sump with an estimated height of 12".
   
   Sadly the only low profile tanks I can find capable of holding up to 100g of water were th 50g stock tanks from rubbermaid. I say sadly as they cost 75$ea. >_< adding 150$ onto the system themselves. But elevating the GB above the FT isn't an option, even with 9' ceilings' as the GB would be a minimal of 40" vs the 32" with a sump system.
   
   Another thought would be to use an indexing valve to fill one gb at a time (48gallons) and use one sump.
   
   Or, use no sump but an indexing valve and place the GB's above the tank (40" height on the GB) and fill one at a time. This would bring the water in the system down to 240 and the water in the tank would fluctuate up to 3.2" at a time bringing the water level down to as low as 12.8" from 16" assuming a 4" gap. This setup would also require 5 full cycles per hour from a 50g sump cycle of 6 and a 100g sump cycle of 3.5 (as both are being filled at the same time)

Another option, kinda 'out there' in a way is to use JTT 27 gal totes.

• The GB would consist of up to 8 of these each 29x20x15 LWH meaning 14" of hydroton, and 93.6g displacement of water if all were filled 13" with watter.
• these are made with '99.99% recycled plastic ... no clue which type they are but hydroponic growers love this tote.
• This option use 100% of my available lighting footprint

1. To sump or not to sump? How many inches max should I drain from a FT assuming these would be over the FT ... this would determine how many totes could be filled using an indexing valve at once.
   
   15gallons = 1" in the FT and one tote displaces 11.7 @ 13" + hydroton or 23.4, 35.1, 46.8 for sequences of 2 3 4 totes being filled.
   
   If I use 4 of the same totes as a linked sump the system would have 333.6gallons and 281.19gallons of volume respectively making the ratio of water to BG about 0.84 if you do just FT to GB it is 240:281.19 which is better as it is positive.
   
   Using 2 totes the flow / ratio numbers would be 286.8gallons in the system making the water to GB ratio near 1:1. This would require an indexing valve or a mechanical rotating valve (have seen some on youtube)
   
   Flow rates: 4 tote sump would mean 3.56 cycles per hour, 2 tote sump would be  6.12 cycles per hour to cycle all the water through the system.
   
   4 totes requires 1 pump
   2 totes requires 2 pumps? and an indexing valve
   no sumps 1 pump and indexing valve
   
   I assume the sump size is > gallons required to fill x amount of GB tubs in case of a power outage the max water lvl would be maintained in the FT. ... wonder if I should move the FT farther from the GB's.
    

  If someone could kindly poke holes, offer suggestion, or modify my thinking I would be grateful!

I have included images, to scale, for consideration in my photo gallery.