Hello, I have recently got interested in water gardening as hobby and I have some question about it. It could be difficult, but I hope you could help me.

Before starting, I want you to know that I'm not so rich in money so I'm trying to save as much as I can.

The pond container I have is actually lamp cover.

It pretty much looks like this but wider. Is this safe? I heard they are polycarbonate plastic.
I've been using it for aloe pot, but after gnat problem, I'm growing them in different pot and I really started to get interested in pond so I blocked bottom hole I made with food grade silicone ?
The one plant I'm planning to put there is Eichhornia crassipes for purifying water for other water plants. Which is the plant I have main question about it.
I red that commercial soil could be bad for them but I probably only have commercial soil and I don't want to go purchase some soils for ponds only.
Also about putting soils to container, it doesn't make me feel safe.
About this, I heard hyacinth <I'll just call it hyacinth> is edible if boiled, so I'm also planning to eat them if they over populate. So, planting them in soil container just doesn't make me feel clean.
I heard that they could grow in soil less medium if they are fertilized, so I'm planning to go that way.
However, do they really need to be fertilized to grow? what happen if they don't?
Well, the growing mediums I bought is pea pebbles and aquarium granite. Going to mix them together and place them up to middle of the pot.
Now about fertilizing, I also don't want to use any fertilizing product that's sold by other people.
Anyone know the method for home made fertilizer for water plants?
I know how to make rice water fertilizer for other plants, but I don't know if that's safe for water plants.
I also have kefir? anyone know if kefir could be used for fertilizer? hehe

I think this is probably weird questions to ask, but many things going on inside my head, and I'm trying to squeeze it as much as possible.

That's probably end of the question. Please tell me if there is anything important things to know for water gardening. Thank you so much for the time and service.

From the pond forum I belong to I have learned that kitty litter makes a good growing medium. Kitty litter is made from clay, zeolite, diatomite and/or sepiolite. Just make sure you get a bag that is not scented or has any other kind of chemicals.

This link may also help you.
http://extension.illinois.edu/...

Water hyacinth is pretty tolerant and needs little nutrient to grow (which is one of the reasons it's invasive throughout the country). The main thing you need for fertilizer is some form of nitrogen. A little goldfish or something would be adequate for that, and the other side nutrients would come along with the fish food.

The more sterile and non-leaching your substrate, the more nutrients will be missing from your aquatic environment. If you decide to plant anything in the substrate, you will require either a richer media under the gravel/kitty litter/etc. or an all-in-one fertilizer solution such as pond tabs.

Thank you for all the answers. Although I was looking for homemade fertilizer, kitty litter could be interesting.. but isn't it expensive? I'll have to think about that.
I wrote above aquarium granite, but it was small aragonite. That can't be replaced as kitty litter right?

The problem with homemade fertilizer is that it's unbalanced and it's missing the minors: selenium, manganese, etc. which are required in small amounts to make plants happy, unless you're doing compost or the like. When you plant in real soil, these required minors are already present to some degree, and the microbes and structure of the soil go a long way to covering over imbalances.

In water, the plant gets exactly what you give it, and the whole environment is a lot less forgiving. You can either use nutritive substrates or you can use something that is carefully blended. You said you didn't want to do the former, and the latter requires a lot of chemistry to do homemade. Fish are one of the few alternative ways to provide water plant nutrients safely, which is why I suggested it. Fortunately, your choice of plant is the dandelion of the water plant world, so I think it will be fine as long as you can get a tiny bit of nitrogen in there somehow.

The kitty litter in question is usually bentonite clay, which has numerous buffering and stabilizing qualities. It is often found in both natural and artificial pond bottoms, so it is well tested and understood.

I actually have used aragonite in freshwater aquariums for fish, but it tends to harden the water and raise the pH, so you'll need a natural counter or opposing buffer to use it so these ranges don't quickly go outside what your plant needs. I wouldn't recommend it for growing plants.

All of our growing environments are chemical and biological ecosystems, but it all happens more quickly and more radically in water. There are tried and true methods for water gardening, but when you wander outside of them you quickly find yourself becoming a chemist and/or microbiologist.

CanT said:Thank you for all the answers. Although I was looking for homemade fertilizer, kitty litter could be interesting.. but isn't it expensive? I'll have to think about that.
I wrote above aquarium granite, but it was small aragonite. That can't be replaced as kitty litter right?

A 25 pound bag of just plain kitty litter (plain bentonite clay) will run you about $4.00.

That's cheap enough. I don't know what I saw when I searched for kitty litter. If I'm going to get that, would those and pea pebbles would do enough for my pond?

I don't have any knowledge for water gardening, so everything just bothers me. Looking up other website doesn't help me finding the answer. I think Kitty litter as substrate is a good idea. However, my question is that what is going to happen. What do I do about the nutrition? do I just leave it in? Will that be enough for the water hyacinth?

Water Hyacinth doesn't need any help to thrive. In many parts of the country it is very invasive. If you have chlorinated water, I would leave it stand in a bucket overnight so the chlorine has time to dissipate between refills.

Do you mean that Water Hyacinth doesn't need any fertilization? they just can live in plain tap water if they left out overnight?

They don't need fertilizer. They don't like chlorine, so if your tap water is chlorinated, let it stand in a bucket over night so the chlorine can dissipate before you use it for the water hyacinths.

Thank you so much for the information! it cleared me out. I will let my tap water stand in a container over night. Thank you again.