Originally Posted by Tigerfish
Wow Byron, that was a great explanation I knew a little of how everything worked but needed the refresher
I do have a question about plants though I never have be able to keep them alive for very long other than the nitrate is there a certain fertilizer I should look into or is it all about the type of lighting?
You're welcome. Sorry to be so lengthy, but not knowing what you do or don't know it's best to be thorough.
Re plants, there are several things to consider. Plants grow by photosynthesis, which is the process they use to convert food into energy. Light is the most important factor, but it must be in balance with nutrients. I usually separate the nutrients into CO2 (carbon dioxide) and trace elements/minerals since these two things are handled a bit differently in an aquarium. Each of these three factors affects the others, and for a planted aquarium to be successful the three must be in balance.
Nutrients are present in any aquarim with fish, but in varying amounts. Fish expel CO2 through respiration, and this CO2 is taken up by the plants. Provided the necessary level of trace elements/minerals is available, and the light is of sufficient intensity and duration, photosynthesis will occur and certain plants will grow well in such a system. This is the method I use, and you can see the results in the photos of my aquaria. I have two 40w fluorescent tubes over each tank, equating to approximately 1 watt per gallon of full spectrum light, on for 13 hours each day. The fish provide the CO2, and I add liquid fertilizer twice a week. I experimented with the liquid fertilizer, observing the plant growth, until I got the amount correct.
The plants I have will all grow well under these conditions. Most of the rooted plants (Echinodorus [sword plants] and Cryptocoryne [crypts] species) are OK, along with Java Fern, Java Moss, Anubias and floating plants. Most of the stem or bunch plants [you buy these in bunches, they have no root systems attached, but roots grow along the stems] require more light than this, although Brizilian Pennywort does well in my 90g. Algae is minimal in my tanks because the plants are able to use the nutrients and light and there is none left over for algae to grab. Algae is better able to convert carbon from carbonates (rather than CO2) than plants are, which is one reason algae is always a problem when the light and trace element/mineral nutrients are greater than what the plants can utilize.
If you go with the high light plants, or want plants that produce flowers and grow like weeds (literally), you must significantly increase the intensity of the light (3-4 watts per gallon) and at that much light CO2 has to be added to balance, or algae will proliferate. And obviously more trace elements will need to be added. That type of planted tank is referred to as high-tech.
Hope this explains things a bit. There are some other things involved, like the substrate (sand, gravel, pebbles...) and water parameters (temperature, pH, hardness) that have some bearing on success with plants, but these are not usually the problem when one can't grow plants. If you can tell me what type of light you have on your tank, and the substrate type, I could probably offer some suggestions for success with plants.