Aquarium Plant Nutrients

To live, plants need many nutrients. Some of these are absorbed by the leaves, others by the roots. Some need more nutrients than others. Some need different water conditions than others. All need the same nutrients.

Lighting

One of the necessary nutrients is lighting. Of course, every plant needs, light; outdoors, aquatic, or desert and every other plant you can think of. Visible light forms a very small part of electromagnetic radiation. Radio waves are examples of a type of non visible light. All the colors of the visible spectrum, which are red, orange, yellow, green, blue, indigo, and violet, combine to form what we see as white light. This is what you see when you look at a sheet of white paper. All the colors bounce off the paper, combine, then enter your eye as white. Plants require the blue to orange-red to survive. When you look at a black sheet of paper, all the light is absorbed and none bounces off. This is black. When you look at a red apple, all the light is absorbed, expect red, which bounces of the apple which is what we see as red. The Kelvin temperature, is an approximation of the color tone of the light ( the higher the bluer, the lower the redder) that is supposedly the color of light that a black piece of metal will radiate if heated to that temperature. Plants use the 3600 to 8500 Kelvin range.

Types Of Lighting

Incandescent- Although this type may be easy to install, cheap to replace, and simple to find, they are not ideal for aquariums much more than 5 gallons. They produce a very yellow light, and are not well suited for plants.
Fluorescent- This type of lightning is somewhat expensive, depending on the brand you choose, the amount of power the hood has available to it, and how many bulbs you have. Fluorescent bulbs are easy to find at any aquarium store. They are also easy to find at home improvement stores. You should always buy them at aquarium stores, because the ones from other stores are usually not in the right Kelvin range as specific ones for plants.
Metal halide lighting form the last part of the light section. These are very intense, very expensive lights suited to only very heavily planted tanks and saltwater tanks with invertebrates. They produce a lot of heat, so are usually fan cooled.
Lights need to be on for 8-12 hours a day. It can be no more, and no less, because they need it to be dark sometimes to function right.

Other Nutrients, besides CO2

Other types of nutrients, called macro nutrients and micro nutrients can be introduced into the aquarium by fertilizers. Some fertilizers are liquid and some are a tab form. It is best to use both types. Usually the tabs are pushed into the gravel and allowed to dissolve, being replaced monthly. The liquid is poured into the water, and is usually replaced weekly. Below is a table which explains most of the necessary nutrients, what they do, and how to recognize deficiencies.

Nutrient Table
Element	Form Available	Major Function	Symptom of Deficiency	Concern Factor*
Macro nutrients
Oxygen	O₂ and H₂O	Major component of plants and organic compounds	Dying plants; dying or dead leaves; leaves yellow	0.02
Carbon	CO₂	Major component of plants and organic compounds	Dying plants; dying or dead leaves; leaves yellow	1000
Hydrogen	H₂O	Major component of plants and organic compounds	Dying plants; dying or dead leaves; leaves yellow	0.02
Nitrogen	No_3- and MH₄₊	Component of nucleic acids, proteins, hormones, coenzymes, etc.	Stunted growth, chlorosis (yellowing of leaves); affects whole plant	1000
Potassium	K+	Cofactor functional in protein synthesis; osmosis, operation of stomata	Chlorosis necrosis (spots of dead tissue) weak stems, roots; older leaves most affected	1000
Calcium	Not Listed	Important in formation and stability of cell walls; maintenance of membrane structure and permeability; activates some enzymes	Death of shoot and root tips; young leaves and shoots most affected	10
Magnesium	MG_2-	Component of chlorophyll; activates many enzymes	Chlorosis of leaves; older leaves most affected	10
Phosphorus	H₂PO_4- and HPO_4-	Component of nucleic acids, phospholipids, ATP, several coenzymes	Stunted growth; plants dark green; affects entire plant	Not listed; usually not a concern
Sulfur	SO₄	Component of proteins, coenzymes	Chlorosis, with veins remaining dark and tissue between light; affect young leaves	Not listed; usually not a concern
Micro nutrients
Chlorine	CL-	Activates photo synthetic elements; functions in water balance	Wilted leaves, stunted growth and roots, chlorosis, necrosis	Not listed; usually not a concern
Iron	FE₃₊ and FE₂₊	Component of cytochromes; may activate some enzymes	Chlorosis of tissue between veins, stems short and slender; affects young leaves	1000
Boron	H₃BO₃	Uncertain; may be involved in carbohydrate transport and nucleic acid synthesis	Death of stem and root apical meristem, leaves twisted, young tissue affected most	Not listed; usually not a concern
Manganese	Mn₂₊	Active in formation of chlorophyll; activates some enzymes	Chlorosis of young leaves with smallest veins remaining green; necrosis between veins	10
Zinc	Zn₂₊	Active in formation of chlorophyll; activates some enzymes	Reduced leaf size; shortened interlopes; chlorosis; spotted leaves; older leaves most affected	Not listed; usually not a concern
Copper	CU+ and CU₂₊	Component of many redox enzymes	Young twisted, wilted, tips remain alive	Not listed; usually not a concern
Molybdenum	CO_4-	Essential for nitrogen fixation	Chlorosis, twisting, death of young leaves	Not listed; usually not a concern
* Concern factor is how much plants can store beyond their needs for growth, IE. plants can store 1000 times more iron than they need.

CO2

CO2 is one of the hardest to get nutrients. It can be come across two ways; DIY CO2 injection, and pressurized CO2 injection. Pressurized CO2 is expensive. It is easier than DIY simply because you can fill up the canister once a year and forget about it. If I had the money, I would buy one. They will set you back $100-600 depending on where you get it and what type it is etc. I am not familiar with pressurized, because I do DIY injection. This involves mixing sugar, yeast, and water to make CO2. I will tell you how it is set up in my 46-gallon bow front tank.

I took 2 two-liter pop bottles, drank the pop (with help of course) and took the wrapper of and rinsed them well. To take the wrapper of, run it under very hot water and it will melt the glue. Anyway, I filled them half full of slightly warmer than lukewarm water, and put two tablespoons of yeast in them. I then put about 3-4 cups of sugar in them each. There is no set rule about the ingredient amount, so feel free to experiment what works for you. Generally the more yeast, the more bubbles it makes, the more sugar the longer it will last. Then, fill the bottles up until 3 inches from the top. That is a long way from the top, you say, but one time I was in a hurry and put to much water in, so when the yeast started to produce CO2 it pushed the solution in the tank and made it cloudy.

I drilled holes in the bottle caps slightly smaller than airline hose, then pushed the airline hose through the hose. I connected the hose with a T-valve and ran the line into my aquarium under a reactor. The reactor is a water bottle, that has the top cut of and has a hole in it with a suction cup that is siliconed to the bottle. I also cut a hole near the top, which is actually now the bottom, to regulate the CO2 amounts. It is possible to kill your fish with too much CO2, but there is a greater chance they will be killed of ph. swings. Make sure CO2 is always producing to prevent this. My ph. is 7.0 and my plants are doing well.