How do water changes work in a large tank like that? Do you just let the plants take care of bioload and just dose ferts regularly?
Easy as pie.
Turn a switch to turn off the UV/pumps, turn a valve(you can turn 2 of them if you want even faster draining) that's 2" PVC. Takes 10 minutes to drain 700 Gallons.
There is a 700 Gallon RO tank in the back and a 1000 gpd RO unit.
We use that to fill as well as a tap line(3/4"). The tap is carbon filtered for the entire home.
We can also use a gravel vac and hose into a drain in the side filter room for spot cleaning if need be.
One thing that can mess with you, not remembering to turn the valves shut after draining, you waste all the water in RO and it can take much longer then.
Otherwise, water changes are easy, likely easier than folks with a 55 gallon tank and lugging buckets.
For my own tanks:
I use 1" flex line and go right outside to the lawn for draining, and simply place the same hose on the bath and run the 1" U shaped hanger for the refill.
I'll go hard plumbing once I move into my own home.
You can automate the water changes also and run the drain/fill inside the walls using hose, PVC, 1/4" or 1/2" lines etc.
Add a solenoid on a timer and a float switch.
Just like an automated toilet flush.
Add a carbon prefilter to the line so you do not need to dechlorinate etc.
Regards,
Tom Barr