Nice looking pups! Will you grow the BD and P14 hybrids together?
To answer your questions about water changes I do things differently than some. I prefer very large 70-90% water changes 1-2 times weekly on tanks without drip systems. Because of the frequency, I have found the fish tolerate the schedule and fresh water very well. These larger volumes would not work if I did the water changes less frequently, as the parameter swings would be more severe. This also would not work well in a lightly stocked tank. I find the large changes flush out so much waste that the beneficial bacteria can crash in the absence of fish waste and cause a mini cycle in lightly stocked tanks.
I would increase your 20-30% to 50% minimum. I think you should also periodically test your nitrate and parameters and see if it creeps up over time. Use this as a guide as to increasing your water change volume and frequency.
You have 5 rays in around 250 total gallons of water. That's a dense stocking, keep that water clean.
Nearly all of my tanks and ponds have drip systems. On those I will do 1 large water change around 80% once every month or two. I drip more heavily than most.
thanks Dieselhybrid,
yes i am keeping the BD and P14 hybrids together.
Surprised to know that 5 pups are dense stocking.... was thinking it be dense only when they are mid teens
intend to test water every 3 days for a start to get an idea on how much nitrates i will be having to decide on water change schedule, currently doing 20-30% every couple of days.... will slowly increase to 50%
As my tanks are in the car porch, pretty hard to keep things neat with a drip system lol
would do larger water change when the pups are older and more stable.... can't bear to lose these pups
thanks for yours and MariaS guidance