Me No Geek: indoor plants in water only (stagnant hydroponic)

I love planting: in soil or in water. When I plant indoor, I choose the lowest maintenance plants that I found googling since I am very lazy to water plants often. Most easily available one in Singapore is Pothos -also known as marble queen. Pothos can survive in still water for many days or even month without changing water.

However, planting only with water in Singapore has constant fear of accidental breeding of dengue mosquitoes. Most decorative plants or even flowers require change of water everyday. On my first try, I used melamine sponge to hold the plant and seal the vase to stop mosquitoes from breeding in the water. It ended up with a few dead leaves.

I researched and found a few things went wrong. Plants draw water by capillary action and transpirational pull which requires at least equal or higher pressure at the roots compared to leaves. When the vase was sealed with sponge (or wet sponge)the pressure in the vase is lower after a few hours or days depending on the evaporation rate at the leaves. This ceases the water being pulled up to the leaves; leaving them dehydrated. So, I replaced with open large cell sponge and most problem solved: no more mosquito or daily change of water.

I leave the plants without changing water for a few weeks and found that their leaves start to yellow. This time I looked for answers in hydroponic planting. To my surprise, it was due to lack of oxygen in the water. I found a site or a blog which says; all living cells needs oxygen and without oxygen cells don't grow.
Old cells die and roots hairs will rot preventing the water transport with slimy coat. This is exactly what happen in overwatering or drowning of soiled plants too.
Many suggest adding low concentration hydrogen peroxide or similar chemical solution which can react or supply oxygen to root cells. But it is expensive in
Singapore. So, the easy way out is change water every few days.

I usually take the roots out, lay them on the floor and spray with a slightly strong shower. This will clean off any dead roots and slime. I suggest not to rub the roots because you will damage the root hairs (you can see tiny hairs if you look close enough ).

Since my indoor plants are mostly for decoration, I don't really need them to grow very fast. If I need to propagate, I will put some plant food and seaweed extract to boost the growth. Other than that I will just leave them in tap water to keep them as they are. They will not grow since there is not much minerals present in the water.

I find that vines are much tolerant than other type of plants when it comes to hydroponic decorative planting. Pothos that I have is exceptional- once I put a single leave in a small bottle with petiole in the water just to see how long it can last without main stem and without any change in water. It lasted more than a month and I wanted to know why. I lifted the leaf up and saw a root sprouting directly below the leaf petiole. Unfortunately I broke the root when I put it back inside the narrow bottle. So I didn't see how it will continue to grow.

Overall suggestion of indoor planting in water:
1. You need to support the plant which allows air to flow in and out of the vase while fully protecting from insects getting access to water (there must be thousands of way or you can just do like mine)
2. Change water once every few days to replenish some nutrients and oxygen

3. Wash the roots to keep them clean and healthy (healthy roots = healthy plant)

I think I should stop here now. See my indoor water plant gallery below. I feel like I live in different world when using glass vases. The crystal clear water and the beauty of roots are just amazing. Another beauty of using glass vases are that you can put a drop of food coloring to match with your mood.