AndEEss

If you can, find a bunch of plants from established aquariums, and put those in immediately. And, similarly, see if anyone near you could give you some well established filter media.

Serious question: How many people do you think are doing 50%+ water changes every day AND are capable of keeping a pH below 7, constantly? Based on the comments on this board, that isn’t a lot of people. I’d say less than a quarter. (Also, nitrite toxicity is the opposite of ammonia; worse below 7)

That’s a really strange mix of fish. Not saying every tank has to be a biotope but the parameters for those species are quite different.

The problem with fish-in is two fold: 1) A “hardy” fish is still being burned by ammonia and nitrite. It just doesn’t die as quickly as a less hardy fish. 2) You’re then throwing a live animal away or sending it back to the LFS so it can be tortured again. Or, if the fish keeper is bad enough at caring for the animals in question, the fish are tortured to death.

A single SDC 6.0 for a ~220g system? At the head you'll be using it at, that's like 800gph, running the pump at full gas. I'd probably get another one and run them at 80%, but that's just me.

To be clear, you should still dose prime when performing a water change to deal with any chlorine or chloramines in the water.

Prime consumes oxygen in water, so I think if you sealed it in a container right away, you'd have a bunch of water that has no dissolved oxygen in it. I wouldn't do that, personally.

I'd do something like this: https://waterandlens.com/planted-tank-automatic-water-change-overview/

I meant why are you replacing filter material at all. The point of a filter is to process biological waste; throwing it out eliminates the ability to do that.

Why did you buy disposable filter cartridges for a HOB?

My floor under my 143g tank is 5" wide hickory boards, with the planks themselves alternating and offset from each other so that they extend 3' on each side of the tank. Underneath, 2x8s at 16" spacing.

What are you doing to "clean" the sponges? What are these "changes" you are doing"? The only maintenance you should need to do with those filters is taking the sponge out, slapping it against a tree two or three times, and put back in the filter. If you're actively CLEANING your filter sponges, yeah, you're going to crash your cycle.

If you’re worried about otos starving, you shouldn’t be considering significantly larger fish that eat the same things. That makes no sense.

Just under 50 psi is about 15 psi too many, FYI…

Correct on both counts. I kill the power to both filters and get my hose going into the water, and dump Safe directly into the outflow. The OP didn't mention any fauna and as he said he just started it, I assumed he was in the process of cycling it.