6500L+ multi-tank sump setup

[joebywan]

Long time perve, first time post

We have a bunch of tanks under the house that I'm looking to reduce running costs & increase the filtration by sumping them all together.

• 3mx90cmx75cm (2000L)
  
  
• 2.4mx60cmx50cm (700L not setup). Has 2 x 1.2mx60cmx60cm tanks underneath (400L each not setup)
  
  
• 3 tier 1.2mx60cmx60cm rack divided into 9 tanks (1200L total)
  
  
• 36 x 40cm[SUP]3[/SUP] (60L x 36 = 2160L not setup). Looking to construct a rack for the 15 extra tanks that aren't in the 3 tier 7/row rack at the moment.
  
  

I've been dabbling with breeding catfish, and my girlfriend wants to breed discus. So we've decided to sump them all together.

Main issue is the lack of space downstairs for viable sump locations. I've picked up a 120cmx60cmx40cm sump (which I know is rather small for this setup).

Layout downstairs:

So I figure I've got bugger all horizontal space, but I do have 2.1m of vertical space to play with. I've constructed myself a shelf to go above & carry a sand/gravel filter & 2 fluidised sand reactors.
It has a 15mm ply top on it now

So I was tossing up between doing a gravel filter like birdman/ken has done or just do a top down sand filter that I scrape regularly instead of having to backwash it. Unsure at this stage. This would do the mechanical filtration for the two reactors. (the pic doesn't have the 3rd one in there, was more mocking up)

Now the interesting parts of this build are:

• The 3m(10') tank is drilled at the bottom in the centre. So I am going to have to do a loop from underneath up to the water level then back down to the sump to avoid draining it all & there will be a T at the top of the loop to avoid a siphon aswell.
  
  
• The bottom row of tanks on all 3 multi-tank racks are either just as high as the sump, or just below. I'm intending on using the 50mm bulkhead at the rear in the sump (on the left in the picture above of it) and use the vertical to drop water out of the pipe into the sump & stop backflow. Unfortunately I've not figured out how I could put a sock on this.
• I'm intending on using Solar Hot Water to heat the tanks throughout the day. This is by having a solar controller hooked up to the Evacuated Tube setup on the roof. Pump in the sump sends water up when the tubes are hot enough. Below is a picture outlining the rough layout of the controller + system.
  
  

So I've got a couple of questions for you guys/gals.

1. Any better solution to getting the return from the lower tanks?
2. Does anyone have documentation on hanging the mains? I was intending on using a 100mm main for the upper tanks & the 3m tank.
3. The 40cm tanks are already drilled twice, 1 at the top, 1 at about 50%. I was intending on putting a valve on the 50% & using for forced water flushes while leaving the top bulkhead without a valve. All inlets will have valves. I can't see any problems with this, can you?
4. The solar system will need a high torque (head height), low flow pump. Any suggestions? In Australia preferable.
5. The return to the tanks & the filtration I wasn't sure whether to use 1 large pump & bleed off with a T+ valve to the reactors, or run two pumps. What do you think?
6. I'm aware that power outages and sump overflow are an issue with such a small sump. I was intending on putting a check valve at the top of the tank return to prevent most of the water flowing backwards, but the issue is the overflows from the tank. My thoughts were possibly using a bilge pump with a float valve on it to push the water to an IBC outside until power returns & I can manually pump it back in.
7. The return to the tanks I was going to make 50mm & have 25mm coming off it to the tanks. Some people in rack setups I've seen plumb a line down above each row of tanks, others just run all of the tank returns from the top straight down to the tanks with poly. Any pros/cons for each?

 

[David R]

Wecome to MFK! Looks like a pretty serious set up, love the dimensions of the big tank.

My 2c; you may want to think twice about hooking them all together if you're going to have a breeding set up with discus. Having the breeding tanks together so you can move fish easily without acclimatising them would be handy, but with your large tanks running on the same system changing the large volumes of water required for raising young discus (some say up to 90% daily!) would certainly not reduce your workload or costs. I think if you really want to hook the larger tanks together do it properly and get a large enough sump to contain the overflow when the power switches off, you really don't want a system that can't auto-restart itself without your help.

Looking forward to seeing where you go with it!

 

[joebywan]

With raising young discus, you only have to change water that often with smaller tanks. The larger the system, the less water changes each tank would require.

Getting a larger sump isn't possible. I've gotta work with the space I have, so it's not an option otherwise I would.

I'm still pricing up a battery backup system to stop the system shutting down in the event of a blackout to completely avoid the issue of overflow. Either that or a generator with electric start and a relay to auto-start it in the event the system loses power.

 

[joebywan]

Also is this the right place to post this type of thread? I noticed there's posts in the DIY projects root, so should it be there instead?