The assembly on this was easy enough. My tank was already full of water so it made it difficult reaching in and attaching suction cups to the air tube and the electric wires. I would recommend putting the suction cups on before placing it in the water and just slide the suction cups to the right place before sticking them to the glass. The instructions were pretty bare bones but you should be able to figure it out.
The crystal does not fit tight to the base. It balances on top of the light emitter. You may want to build up substrate to hide the gap or put plants or something if it bothers you.
I noticed that it was quite noisy and wondered how my fish liked the noise and vibrations in the water .. probably not so much. I lifted the crystal off the light/bubbler base and it became much more quiet. I'm at a loss as I followed the instructions and kept it away from the sides of the aquarium but it has to sit on the bottom either on the glass or on top of substrate. I have it sitting on substrate. I'm going to prop up the crystal so it does not rest on the light/bubbler and see if that solves the problem.
This is just poor structure design but it is very beautiful so I'll try some modifications and make it work.
The light seems to come out of the middle crystal and not so much the side crystals. They are just not as bright. I think it is because of the way the crystal top sits on the light/ bubbler base. Raising it up seemed to spread the light to the other crystals better.
If the bubbler fails then I will replace it with an external air pump and round bubble stone. I think an external air pump would be more quiet anyways.
Make sure you clean the bubbler regularly to ensure it keeps working [per instructions]
Overall, I'm happy with the light and the crystal decor. I'm not so happy with the vibration/noise of the bubbler.