Photosynthesis/Respiration

During the time that aquarium plants are exposed to light, carbon dioxide is absorbed and oxygen is expelled. The gases enter the plant mainly through the leaves. The carbon dioxide and water are chemically combined with the chlorophyll in the plant to produce simple sugars. The sugars are converted to starch and oxygen is produced as the by-product. The light in your tank is most important with respect to the chlorophyll. The chlorophyll is what absorbs the light to create the process of photosynthesis. The aquarium plant naturally absorbs more nutrients through the roots during this time.

Respiration is the opposite of photosynthesis. When the lights are out, the photosynthesis process ceases but the respiration continues. The aquarium plant will use oxygen to break down food substances, which is released as energy in the form of heat. Carbon dioxide is produced and expelled as a result of this process.
So, when the lights are on the plants absorb carbon dioxide and expel oxygen. When the lights are out the aquarium plants absorb oxygen and expel carbon dioxide.(Back to top)

Chlorophyll

The pH Values

CO²

General Hardness

Carbonate Hardness

Aquarium Plant Fertilizer

Changing the Water

Heat

Substrate

The substrate is the floor of the tank and the material where the aquarium plants will root. The most important thing here is that the substrate should be a material that does not adversely affect the water conditions by raising or lowering pH and water hardness. You want a happy medium here. Things like crushed coral or shells and certain kinds of gravel will create a high pH and high carbonate hardness, which is not good for your aquarium plants. On the other hand low pH and very soft water can cause root-rot, which in turn will lead to algae growth. 6.8 to 7.2 is pretty much ideal depending on the type of aquarium plants you select. Stick to natural substrates, avoid synthetic materials, gravel that is coated with epoxy or glass beads and colored ceramics.

The substrate material should be between 3 and 8 mm thick. Large granules will block root growth and smaller ones can actually crush the roots. It is recommended when starting the tank that you add the substrate in phases. For example, mix the first layer with the solid fertilizer, (remember - less is more) and place that in the tank. Then add as much as two additional layers with the finest granules on the top layer...not that the additional layers do not contain fertilizer. Remember to use a bowl or plate on the bottom when filling with water in order to avoid churning the fertilizer up.

You will also have to provide substrate at the proper depth for your aquarium plants. There are three groups of aquatic plants that can be classified by root type.

Plants that don't need sand but attach their roots to rocks or wood such as Anubias, Microsorium and Bolbitis.

Plants with large rootstocks like Aponogeton and Nymphaea.

Plants with long stems like Hygrophila and Rotala that have shallow roots.

Plants like Cryptocoryne and Echinodorus that are deep rooted.

So to give you an idea of the depth of the substrate you must consider the type of aquarium plants you are going to use. The deep-rooted ones will of course require the most depth. If they are planted in substrate that is not deep enough the roots will become entangled and the aquarium plants will suffer from a lack of nutrients. The deep-rooted plants need at least a 6 cm deep substrate (2 to 3 inches). (Back to top)

Lighting

First and foremost, achievement of a balanced tank is most important. A balanced tank can be achieved at both LOW LEVELS of light and HIGH LEVELS of light.

FACT: A NATURAL AQUARIUM IS A LIFE SUPPORT PROCESS WHEREIN THE PLANTS AND THE FISH COMPLEMENT EACH OTHER.

• DURING PERIODS OF NO LIGHT FISH CONSUME OXYGEN AND RELEASE CARBON DIOXIDE.
• AQUARIUM PLANTS DURING PERIODS OF LIGHT CONSUME CARBON DIOXIDE AND RELEASE OXYGEN.

THIS PROCESS GOES TO THE BENEFIT OF THE FISH AND THE PLANTS AND WHEN ALL IS WELL, YOU HAVE WHAT WE CONSIDER A  BALANCED TANK .

THE DEGREE LIGHT AND LEVEL OF CO2 ARE CRUCIAL FACTORS IN A  BALANCED TANK 

Light and CO2:

To keep your aquarium plants healthy, the light and CO2 must be balanced.

• If the light is very intense and there isn't a corresponding larger amount of CO2, the light can harm your aquarium plants.
• Too much CO2 without a corresponding amount of light will affect your aquarium plants ability to photosynthesize, and can also harm your fish.
• A balanced tank will have more plants than fish.

Aquarium plants are grouped in low, moderate and high light requirements. Plants with low light requirements, such as Java Fern, Anubias, Cryptocoryne and various water ferns like Bolbitus Heudelotii, can do well in 1 watt per gallon or even less. These plants naturally photosynthesize slowly. (They do however adapt very well to high light levels) There are also many aquarium plants requiring moderate light levels that survive just fine in low light conditions. They just grow slower and less vigorously.

Plants that require moderate light can usually do well with light levels as low as 1 to 1.5 watts per gallon. The difference you will find in these lower light levels is that photosynthesis is slowed, and the aquarium plants grow slower and less vigorously than they do in higher light levels. Also, some red plants have a tendency to lose their color.

Strong light levels are considered to be 2.5 to 4 watts per gallon, and there are certain aquarium plants that require more light to thrive. You will, however, notice a substantial difference
in the vigor and beauty of all your plants when they are grown at higher levels of light, but CO2 injection will most likely be required.

So, what I'm trying to say is that you can have beautiful tanks at low, as well as high levels of light, through aquarium plant selection and the achievement of a proper balance between the amount of the light and CO2. (Remember CO2 levels can be attained naturally through the normal process of photosynthesis, when we add more light to increase the photosynthesis process for brighter and more vigorous plants CO2 injection is usually required to balance the tank).

OH GEEZ you say! How can I handle that? Well, this is the easy way.
Look at your aquarium plants and fish to see what's happening. If you notice a problem make an adjustment. There are also test kits available for this purpose. (Note: last months newsletter included a chart to measure CO2 levels)

NOT ENOUGH CO2: When there is a deficiency of CO2 the aquarium plants stay small and grow slowly, sometimes you will also notice rough deposits on the leaves, this is known as biogenic decalcification. It could be that you have enough CO2 in your tank, but you could be allowing it to escape by over agitating the surface of the water. CO2 escapes the surface of the water as a gas. So test, and if necessary, turn down those air stones, make sure that the return on your filter doesn't splash. If you're running the venturi on your power heads turn them down or off.

NOTE: It's important to have water movement in your tank, still water is not good for aquarium plants, just make sure that it is not over agitating the surface of the water.

TOO MUCH CO2: If you have too much CO2 in your tank your fish will be at the top gasping for air. This is caused by oxygen deficiency. READ THIS CAREFULLY: Deficient light can cause this problem, but; you would have to be adding CO2 directly to the tank in order for this to occur as a result of a light deficiency. So please take this into consideration: In most cases, oxygen deficiency is caused by inadequate tank maintenance, dirty filters and too many fish.

You can tell if aquarium plants are photosynthesizing by observing the plants. When small bubbles form on the leaves of plants it is a sign that photosynthesis is occurring. Many hobbyists refer to this as pearling.

What kind of lights should I use over the tank?
There are many lights on the market for lighting aquariums. There are mercury vapor lights, halogen lights, and fluorescent lights. In most instances the fluorescent lights work the best. In our opinion halogen lights should be reserved for very deep tanks, 36in. or more, or used as pendant lights over open tanks, which is the best use of these bulbs. Mercury vapor lights are also best suited as pendants over open tank, but remember, mercury vapor lights are not energy efficient. Mercury vapor lights also have a lot of the yellow spectrum, which can create algae problems.

Want to know what makes a fluorescent light work? Well it's a tube with a partial vacuum inside and a small amount of mercury vapor. When the light is turned on the vapor is ionized and gives off ultra violet radiation. The inside of the tube is coated with phosphor powder; this powder gives off light when stimulated by the ultra violet radiation. That is what makes the light. The  recipe  for the phosphor powder that coats the inside of the bulb is what determines the color spectrum of the light.

Here are a couple more definitions you will find helpful:

Kelvin: This is how the color temperature is measured; it referred to as degrees Kelvin. It is a measurement of the warmth of the light. According to this scale 3500 degrees K would be a warm reddish light; 5000 degrees K would be like the sun; 6000 degrees K in this scale is much hotter, but the spectrum is blue which is a little strange to most of us, but to the scientists out there I'm sure it makes sense.

CRI: This stands for Color Rendering Index. On a scale of 1 to 100 it tells you how true the illuminated color of an object is under a particular light. Good aquarium lights will have a rating of 85 or higher.

Lumens: This is the light output or intensity measurement.

Fluorescent lights also come in many flavors. You can purchase the standard bulbs, VHO (very high output), or compact fluorescents.

Select a light from 5000 degrees Kelvin, since this color temperature is closest to equatorial sunlight at noon, to 6700 degrees Kelvin, which we believe looks the best in an aquarium as it is a whiter light and aquarium plants do very well with it. Select a light with the highest CRI rating you can find, it should be about 85 or better.

Be careful, when you purchase your bulb that you are buying one designed for aquarium use. Many  plant bulbs  or  horticultural bulbs  are not suited for aquarium use, first because water filters the color spectrum and second because they usually only provide the essential waves required by land plants. Also, their intensity is only about one-third of that found in a normal fluorescent bulb. So just make sure that you purchase a high color performance florescent bulb, and it should say for aquarium use some where on the packaging. These bulbs are available through many manufacturers and are not necessarily limited to the ones found in your local fish store. I've recently noticed that a couple of our local Home and Garden Stores are now carrying Phillips, Vita, and Otto Aquarium Lights. Just be sure to purchase an aquarium light and not a horticultural light.
It will state that it is an aquarium light on the package.

When to replace bulbs:
Usually 50% of the color spectrum is lost at the half-life of the bulb. So they need to be replaced at that point. This is usually about every 5 to 6 months for normal fluorescent bulbs. Compact Fluorescents have longer life and they normally need to be replaced about every 10-12 months. To your eye the lamp might look fine, but the diminished color spectrum can cause the natural biological photoreactions in the aquarium to deteriorate.
The difference between fluorescents and compact fluorescents is the intensity of the light. For example:

Sun Glo Florescent 24  Light 20 watts, 4200 kelvin, 1230 lumens (light intensity)

Power Compact 22 11/16  light, 55 watts, 6700 kelvin, 4230 lumens (light intensity)

Basically, with power compacts you get more light for the amount of space and connections required. Power compacts are an excellent choice for planted aquariums. Keep in mind that you cannot simply replace your normal fluorescents with these because they require a different ballast and connections. There are retrofit kits available. Also, aquarium manufacturers, such as All-Glass are now offering these lights as upgrades. They also have a compact fluorescent light hood that is sold as a separate item.

HOW DO I KNOW WHEN MY AQUARIUM PLANTS AREN'T GETTING THE RIGHT LIGHT?

Here are some good rules of thumb that apply to light related problems.

Tall leggy plants are a result of lights with too much red in the light spectrum.

Low, squat growth is the result of too much blue in the light spectrum.

Stunted growth and normal light deficiency symptoms described below are caused by too much green and yellow in the light spectrum.

Symptoms of Insufficient Light: The leaves are pale green to yellowish, the stems are weak. Stem plants have few leaves and long internodes; growth near the light is vigorous and the lower portion of the stem is bare. Rosette plants have small leaves on weak stems.
The other thing you'll really notice is diatom algae. This can be caused by several things; not leaving the lights on long enough each day; lights are old and have lost their spectrum; algae or calcium build up on the top of your aquarium; too many floating plants; or, you just don't have enough light.

The deeper light penetrates into water, the more its' intensity diminishes. There are other factors that affect lights ability to penetrate water. For instance any of you who use peat or peat extract, be aware that the brown color causes the water to absorb a great deal of light, thereby diminishing the affect of your lights.

I sincerely hope that this information is helpful. I have many customers that have been under the impression that if they didn't have 2-3 watts per gallon on their tank that they couldn't have aquarium plants. Well, that's not true. So it doesn't matter if you have a state of the art tank with all the bells and whistles or a gold fish bowl, there are aquarium plants for you and your fish to enjoy.

Algae in Perspective

There is a separate article on algae that goes into the specific types, their cause and effect. In this article I would like to discuss it in general and provide some specific pointers on how to set up a tank to keep things in balance so that algae is not such a big problem.

Every healthy tank will have algae in it, whether you see it or not depends on the tank conditions. Algae are a result of too much phosphorus and nitrogen in the water. The reason this occurs is usually too many fish in relation to the number of aquarium plants. So it is always good to keep a few healthy fish to consume the algae, and make your tank active, but always be sure that you have a great number of aquarium plants that grow and consume the nutrients in the tank as well. In other words keep a nice balance. Lots of aquarium plants, few fish.

Some plants consume more algae causing nutrients than others, these are usually the faster growing ones, for example: Hygrophila difformis, Hygrophila polysperma. Water sprite, anacharis, hornwort, etc.

There are very good recommendations for algae eating fish in the species tank articles, but a few good ones are Otocinculus affinis, Crossocheilus Siamensis(note this is a true flying fox from Thailand, accept no substitutes), Ancistrus, and last but not least, Amano Shrimp. The Amano shrimp will eat the dreaded brush algae, and many other forms as well. The only requirement is that they have enough calcium in the water column to shed and regrow their shell.

Snails: Snails do eat algae the only problem is that they multiply so quickly. If you like snails, and snails are usually inevitable in one way or another with a planted tank add some fish that eat them to your tank to keep the population in check. These fish would include Clown loaches or Ancistrus for example.

These are a few pointers that might also help you to keep your algae in check. Remember there is very little difference in a tank full of algae and one in which the algae is completely invisible. So a little change in the wrong direction can make a big difference.

• Be sure to add lots of aquarium plants when you first set up your tank. The hardier ones add the more delicate ones after your tank has matured.
• Never use an under gravel filter, this depletes the substrate of nutrients and sends it back out into the water, which encourages algae growth.
• Never use fertilizer that contains phosphate or nitrate. Good aquarium plant fertilizers are free of these elements.
• Do your water changes on a regular basis at least 25% every two weeks. If you have algae visible you can do as much as 50% a week to get things back in balance.
• I do not recommend using Algae destroyers. These are chemicals sold to kill algae. The reason for this is that I believe it does destroy the algae, but the dead and decaying algae just creates more nutrients for you next algae bloom. Best to do it the old fashioned way in the long run.
  (Back to top)

Algae

Algae is part of the plant world known as Thallophyta, they share this part of the world with fungi. The incredible thing about algae is its ability to grow and survive in the worst possible circumstances over very long periods of time. Algae can survive in plant form and also in the form of spores. So even if the aquarium plant dies the spores can survive and when conditions permit they can regenerate the plant. Thank heaven there are only a few varieties that really affect us, and I will try to describe them for you.

Green Algae: These algae can appear to you in several ways. Sometimes it just makes the water look green, other times it's a green film that adheres to the sides of your aquarium. In this form it is referred to as unicellular. In the multi-cellular form it can also make your water look green but it is very noticeable in that the cells are attached to one another and form long stringy tufts of green yuk.

What causes this and what to do? This is usually caused by phosphate and/or high nitrate levels in your tank, or if the tank is too brightly lit or the sun is hitting the tank directly.

It can also be caused by overfeeding your fish or over fertilization. You can remove the threadlike tufts of algae by hand, and wipe down the sides, clean off any decorations etc.

Then the best remedy is several water changes. If you are doing several water changes be sure to clean out your filter as well. If you have a diatom filter this will clean it out quickly. When you do your water changes be sure to hydro-vac the bottom as best you can. Algae eating fish also help.

Diatoms: This is that ugly brown algae that forms on the sides of your tank, on your decorations, etc. It usually is found in a new tank. It is usually due to insufficient light, oxygen deficiency, and/or excess nitrate. The cure is simple wipe it off, hydro-vac the bottom well when you do your water changes. Algae eaters will also help. I have found that this algae usually goes away after your tank settles in for a few weeks.

Red Algae: This is the worst algae you will encounter. This appears as blackish dots on aquarium plants, wood, etc. (aka:Black dot algae) It also appears like bunches of thread known as beard algae, or small clusters or tufts known as black brush algae. This usually appears in nitrate-rich water with ph over 7.0 (C0² deficient). This form of algae is very common to the cryptocoryne species of plants, and several others imported from Southeast Asia. This stuff is practically impossible to get off the leaves, I've heard of scraping it off the leaves with your fingernails, but I always seem to damage the leaves when I try to do this, and I can never get it all off so it grows right back. Just remove the leave is my best advice. Trim the plant back and get rid of all of it. Scrape it off any decorations, or if it is on the sides of your tank. Do a good water change and reduce the PH level if it is high. Adding or increasing your CO2 level will usually reduce the ph and prevent this stuff. Also, if your tank lights are getting old they could be losing their color spectrum and this will add to the problem. There are a few Algae eaters that will eat the beard Algae, such as Crossocheilus Siamensis (true Siamese flying fox from Thailand-no substitutions) but, even these little guys cannot do away with an infestation, or keep up with it if it is rampant.

Blue-green Algae: If you have this you will seem real thick blue-green, violet or black brown algae on the bottom of your tank and all over everything. The water will smell very bad. This occurs in a new tank when the environment has not yet stabilized or in an old tank where the bottom has compacted. It usually occurs when the tank is not properly maintained - plain and simple. To prevent this, do your water changes on a regular basis, always hydro-vac the bottom, and keep your filter clean. Do not overfeed your fish.(Back to top)