Ira

Cement on its own probably wouldn't work well to hold the rocks together, hence why it's mixed with sand to make mortar or sand and crushed rock to make concrete. A few weeks should be fine if it's somewhere with a good flow of water, Under a downpipe would probably be perfect. If it's going in with africans a day or two would probably be good enough.

You could probably get most of the way there with an autotopoff, cheap timer, relay and a solenoid valve on the filter inlet. Switch off the filter, open the valve and back flush the filter siphoning water out of the tank.

Just make sure to get a silicone that says aquarium safe(Not many) or doesn't have any anti fungals or similar in it. And concrete is fine, just increases your PH. Like Alex said just soak it for a while.

Now, what I DO like is the nice simple way it's it has of gauging the filter restriction, with the two tubes showing water head before and after the filter element.

Lazy cleaning the filters when they need it? No, that's just practical.

Hmmm, I figure I'd spend an hour every 3 months cleaning my filters, $0 replacing filters. Or 4 hours/year. Say my time is worth $20 an hour that's $80nz cost to clean filters per year or $65us. So that means if I bought one now I would break even in May 2051.

If you're really worried give it a good boil, and a couple water changes. Should get all the sap out.

Odering's? Black mondo grass is not aquatic, it may take a little while to die, but it will die. Baby tears might work, I suspect there are a bunch of different species using that name, so it's hard to say for sure if the ones that you have access to specifically will grow. Otherwise your best bet is some of the pond plants. That's if you don't want to go to all the different fish shops and buy actual aquatic plants, or get them from trademe/other local people. They're not expensive.

Not unless you go to ridiculous levels. Where you're blowing your filtration sponges apart, tearing bits of debris apart into smaller particles, etc.

They can also occasipnaly eat very small fish fry. The only ones in the pond would be goldfish so thats a good thing.

Why do you need more? They also eat bugs.

Because they're cool and pretty. Why wouldn't they be good?

Super glue, silicone, kneadit, epoxy, pvc cement, cable ties...

Dragonfly nymphs. They're good for the pond. They may eat the occasional goldfish fry and the grow into dragonflies. Guess that makes them double good. Suppose they might be damselfly nymphs too.

You should probably drop the filter socks lower so if they clog up and start overflowing they'll overflow inside the sump. Nothing worse than being busy for a few weeks and flooding the house. Otherwise looks good.

Yup, just some little sheet of bacteria or fungus. It's pretty normal, don't worry about it.

I still say, put a sheet of sponge where the filter wool is now, you can put the filter wool under it above the bioballs.

That's a different issue, that's particles getting past your filter. You should always have coarse filtration before fine filtration, not fine first. In this case what is likely to happen is the filter wool clogs in about a few days and then the water looks like it will overflow into the area where the noodles are.

That's the point. As it is the first thing the water hits is filter wool. Any mechanical filtration after that becomes pointless.

Yeah, always coarse filtration before fine. You could probably even put the sponge you have in place of the filter wool.

And I can't swim anyway.

There's not much point putting sponges after the filter wool, the wool won't leave anything for the sponges to filter out.

I'd help, but...

Cement is glue/binder, usually portland cement made from ground and baked limestone. Concrete is sand+gravel/crushed rocks mixed with cement. Mortar is sand mixed with cement. The term "Asphalt" is also incorrect, by the way. Asphalt is a cement used in concrete which would most accurately be called asphaltic concrete. I suppose you could also have asphaltic mortar.

You already have mechanical filtration, that layer of filter wool. But you could take that out, fill the area under it with sponge and fill the next section up with noodles.