Automated water change question

Automated discus tank water change system:

Hi there,

New member here and happy to be part of the discus team

I’m hoping I can get some pointers or advice if there is a flaw in my proposed automated water change design.

A 530L (140G) bare bottom discus tank will be in the living room with a bean animal external overflow box. All the plumbing will be travelling down through the floor into the basement .

In the basement I will have a 500L (132G) treated water tank with a float valve to switch on a submerged pump . This tank will also have a float valve to open the tap water to refill . A VERSA PERISTALTIC DOSING PUMP will administer a water primer set to the amount of water drained and reintroduced.

Next to this water tank will be a 150L (40G) sump with a iwaki md55R return pump into the display tank. One 500w heater in the mechanical filtration receiving chamber and another 500w in the last return chamber.

I’d like to implement a canister filter with no filtration under the display tank which will be connected to a smart wifi timer plug to drain a certain amount of water straight into the bean animal emergency drain pipe which will fill an outside rain water tank all with gravity. So let’s say I have 600L of water (display and sump ) and want to dump 100L an evening as an example. I preset a Wavemaker to activate at the same time as drainage to “hopefully” stir up detritus enough to get sucked out via the “ unfiltered” canister pump into the outside rainwater tank which will only be used for the garden. As this drains the iwaki is still operating water from the sump . I’d like to them implement a float switch in the sump return chamber to activate the “treated” fresh water pump to pump water into the first sump chamber with heater nr1.

Note: the reserve water tank pump will flow at a higher rate than the iwaki. So in theory the iwaki will continue as per normal and pump the fresh water into the display. Once the max height float switch gets activated the reserve tank pump gets switched off.

I assume the fresh water being introduced in the first chamber with a heater travelling past the second heater in the return chamber should be heated having mixed with the already heated water to the display with not much of a change in display tank temperature . I could put a 3rd heater in the reserve tank but would like to avoid the wattage if not required and just have 2 heaters in the sump either end. 1000w I think is ample for around 600L of water for Discus.

I also need a float switch in the reserve tank for a valve to refill the reserve to a certain point. Ideally I like to only drain a 3rd of this 500l reserve at max daily which needs to be refilled after the pump to the sump has stopped. This way I won’t have untreated water going into the sump. Ideally I’d only like pre treated water to go into the sump. The prime treatment will be on a Versa dosing pump set to whatever water will be lost daily.

I think the key here is tune the dc reserve pump to the exact flow of the iwaki with a throttle. That way the return chamber won’t run dry. It will send fresh water up with the pre heated sump water to the display. Then when the overflow kicks in the water level in the sump return chamber will rise to the original water level , deactivate the reserve water pump and the water change is complete.
NOTE: the sump return chamber does have an overflow which will be connected to the same outside garden tank the display energy drain pipe is connected too.

So in theory all will be governed by the canister filter in the display stand. Let’s say I have it on a timer to dump 100L (which I will calculate) the sump will start to empty once the overflow stops flowing. THE TRICKY PART is to set the float switch max and low to activate the reserve pump . I will investigate which types but in theory this should all work.

Please correct me if there is any issues and what float switch devices would you recommend for this setup. I’d prefer it to be as accurate as possible.

Thanks in advance