Yes patience is one thing, a lotus or actualy a Nymphaea needs a certain age before it will flower especialy the bulb var. need to mature. For the rest..
Respectively high temperature, high light, good fertilization and extra co² will definitively help in indoor condition. Relatively to sun shine, artificialy there always will be rather low light condition for a lilly, but it can be done. Most important is low flow. Lily is a plant that prefers rather stagnant conditions..
These all are combinations in conditions not realy favorable for an aqaurium.. Meaning, higher light and fertilization in an aqauarium also requires a disirable filtration and flow.. In a rather confined space where flow can't disperse enough the lily floating leaves and flower bud will always be rather close to the filter outlet always recieving the full blast.
Thus it's mainly a mechanical issue in such a rather unatural invironment. The floating leave will constantly be draged under the surface. It's a leaf that actualy is emersed form and wants a lot of co². If it doesn't get this from beeing draged under the surface the plant will need to put energy in growing longer leafstems to finaly reach the desired surface. Usualy when the leaf reaches the glass side panels and can't be dragged anylonger. Once you get it to develop a flower bud, the same thing happens, it needs to be over the surface and it will keep on growing a stem till it does. Because of this it will grow a rather much to long stem that wont be strong enough to erect the flower bud out of the water. Naturaly it needs a relatively firm short and rigid stem for this.
I succeeded only once to make a lily flower in a 50 litre high tech aqaurium with a 4 x turn over.. And i realy had to help it with supporting the flower to protect it against the flow. It was not only a struglle to get the lily to flower but also to keep a high enery tank running properly with such little flow.
https://www.ukaps.org/forum/threads/i-think-i-am-in-love.37099/
Best changes to get lilies to flower are very large and tall low energy and low flow tanks. These have relatively high light at the surface. This to have some par at the substrate level.. Till now mainly seen this in the Discus tank community..
Long story short, ramp up the light, lower the flow and spoil the plant with some extra clay tabs..
🙂 And if it does, stay up at night to enjoy the flower, Nymphaea zenkeri is a tropical nigh flowering lily.
🙁 🙂
Unfortunately this fellow doesn't describes his tank conditions.
https://www.myfishtank.net/forum/threads/nymphaea-lotus-zenkeri-flowering.62310/
