[Michael]

Welcome to APC!

Healthy plants, especially emersed ones like your lucky bamboo, take over the role of beneficial bacteria and biofiltration in fish-only tanks. We don't even "cycle" Walstad tanks in the usual sense of the term.

Please post pictures of your bowl.

 

[Michael]

Nice!

Yes, you can take out the old biomedia. Yes, do a water change. You probably don't need to do anything about the smudge. Add more emersed or floating plants. I like frogbit for things like this. It has attractive floating foliage and you can easily thin it when needed. And unless you need the glass cover for some specific reason, take it off for better gas exchange and access to atmospheric CO2.

 

[Michael]

All of my tanks are open top and my tap water is hard. I top up the tanks whenever they need it, and do a large water change three or four times a year.

 

[Michael]

Yes, much too far away! The lamp needs to be no more than 12" to 18" above bowl. Mistergreen's suggestion is great, and buy a simple plug-in timer for it. Start with about 8 hours a day, then work up slowly until you see good growth without too much algae. Water lilies flower in my tanks with the lights no more than 3" above the water surface.

 

[Michael]

Sounds like the new light solved many problems. Corn cob LEDs are not very directional either. Look for an LED spotlight or floodlight. These will direct more of the light downward into your bowl.

 

[Michael]

I'm surprised your lily hasn't grown some floating leaves yet. Am I missing something in the photo?

 

[Michael]

It can take a while for newly planted water lilies to send leaves to the surface. Until it does, keep the water surface above it clear of floating plants so that the lily gets plenty of light as mistergreen suggests. Once those leaves hit the surface they will push the floaters out of the way.

 

[Michael]

Expect rapid growth after that leaf makes it to the surface. It will have more light and access to unlimited atmospheric CO2. Water lilies also have a strong ability to move oxygen from the leaves to the roots. This enables them to grow in anaerobic soils.