Since re-doing the tank & swapping the substrate for plain black limpopo sand, things seem much better.
Fish have survived just fine for about a month now, where they would have previously been dying off by now.
I haven't been doing the 'just in case' water changes as I was, measuring what's...
Planting:
I've added some Feropol and Interpet 'Fast filter start' and have just turned the CO2 back on.
Some time over the next few days I'll watch the pH for a day and tweak BPS and timing from there.
Once I know that's set sensibly, I'll move a few fish from a smaller tank into this one...
I've got the tank re-done over the last couple of days.
It's been quite a mission. I really hope things'll thrive in it now.
A few pics for anyone who might be interested:
Before:
Taking plants and hardscape out:
Storage for plants:
Pipework and inline heater & defuser in bits...