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Plant Primer (Low-tech Approach)

Date: Sat, 24 May 1997 13:16:22 -0400 (EDT)
From: Earle Hamilton <>
Posted to the Aquatic Plants List

For the past three years I have been working on a fool proof method for low tech plant tanks. Putting all of this down in writing is an invitaion to flames and controversy but I think it has merit or I would not be taking up the bandwidth. Some day I will get pictures of some of the tanks set up using these simple methods. I will expand the text where needed and try to get published, probably in my favorite magazine, AFM.

As a disclaimer, there are no doubt dozens of ways a low tech tank can be set up. Dan Q. has given you his approach. When you consider that each area of the country has its own water chemistry what will work for one will not necessarily work for another. I am not claiming this approach will work for everybody, but I do claim that everybody who has followed this approach in our local water chemistry area has had the same results.

I will also tell you that several folks have set up tanks using the methods described here and six months later the tanks were awful. Full of hair algae with most of the plant species doing poorly. The problem was always tracked back to not doing regular water changes.

You can save lots of reading by letting me summarize.

  1. Change water a lot
  2. Don't use air pumps

For more, read on.

Plant Primer

Many excellent references to growing plants are available. The purpose of this paper is to summarize a few fundamentals that work for me.

It is good to understand LIVE. A plant is either growing or dying. We learn in basic science that plants give off oxygen and consume carbon dioxide. This process only occurs when plants grow. Growth involves storing starches and other stuff that makes a plant a plant. Aquatic plants need sufficient light, nutrients, proper water conditions (temperature, pH and water movement) and for rooted plants, proper substrate. A dying plant will rot and give off carbon dioxide and other byproducts of decay.

Benefits of live plants include, but are not limited to:

Growing plants consume fish wastes. But plants will not remove all wastes since the fish load in our tanks is much greater than what would be found in nature. So having plants will not eliminate the need for occasional water changes. If the aquarium is considereed a closed system then adding fish food will require an equivalent removal of material by pruning or removing extra plants.

There is another reason to make regular water changes. Plants produce their own set of chemicals to protect them from being eaten and to protect their space for growth. In 1995-6 there were excellent articles written in the Aquatic Gardener about this interesting phenomena called "allelopathy". Allelochemicals are almost impossible to measure toxins that keep other plants from doing well. Where water changes are infrequent, such as every six months or so, the tank will tend to a single species or two of plant. Allelotropes kill off less competitive species. The easiest way to control allelotropes is by water changes. If you want to see some amazing picture of planted aquariums, get "Nature Aquarium World" by Takashi Amano (t.f.h.). Amano lists specs on how each tank is maintained. Most of these extraordinary tanks get 1/3 to 1/2 water changed ever week!

One of the recently published books on growing plants stated that regular water changes are necessary to replace minerals and nutrients taken up by the plants. The previous two reasons suggest water changes dilute toxins produced by fish and plants. No matter, what is important is to change water on a regular basis.

In 1947 I was given my first aquarium. In those days air pumps were prohibitively expensive so I did without, as did nost aquarists of the day. But I had pretty good plants. We knew nothing of the nitrogen cycle and it was believed that very old water was best. Water was added to take care of evaporation and the lime buildup was heavy. After several years the tank required complete tear down and the mud in the gravel was excessive. In the ensuing years many changes have taken place, but some, such as air pumps, are not good for growing plants. Listed below are the main points or "success items" for low cost, low tech, low maintenance good looking plant tanks.

  1. Use undergravel filters. Do not use air to make the water flow. Use a power head and do not turn on the bubbler. Set the top of the power head about 6 inches above the gravel unless the tank is very deep. For deep tanks set the power head 6 inches below the surface. Keep surface agitation to a minimum. This provides ample filtration without driving off the carbon dioxide. Outside filter are OK too but avoid too much surface turbulence. My personal preference for UG over outside filters is they are cleaned when doing water changes (see below) and they don't add to the clutter by hanging on the back of the tank.
  2. Change 15% to 30% of the water every two weeks and use a gravel vacuum. Push the gravel vacuum all the way down to the filter plate unless the roots prevent this. There should be at least two inches of gravel over the filter plate.
  3. Use fluorescent light 1 1/2 to 2 watts per gallon for 10 to 12 hours per day. This assumes no natural light. Replace bulbs every six months if you see a reduction in growth. When bulbs have a black area at the end they should be replaced. Use any of the bulbs reported to be good for growing plants and mix them if you want to get a different color tone. There is a strong body of evidence that says the spectrum is less important than the intensity so the use of expensive bulbs can be challenged.
  4. Use a liquid fertilizer such as Tetra's Florapride. Substrate fertilizers are not necessary but if you want to experiment, try a second tank with substrate fertilizer and see if you notice a significant difference. Of course with substrate fertilizer you will not be able to use an undergravel filter.
  5. Start with faster growing plants. Use enough to get a head start on algae.
  6. Be aware it takes some time to see any real change in plants. It will take about 3 weeks to see improvement and it will take almost that long for plants to show distress. There are exceptions of course but this is mentioned so you will follow the water change schedule and not wait for a problem to show. By the time you see a problem you will be playing catch up to make corrections.
  7. Use Malaysian livebearing trumpet snails. They do not bother plants, are difficult for snail eating fish to eliminate and they do a good job of eating extra food.

Algae. There is no way to avoid algae. There are many types of algae and each has its own special requirements. The subject is too extensive to get into here but as a point of common sense - - Algae Are Plants. They require the same basic stuff as the "good" plants. Therefore the plants we want are in competition with algae. For fewer algae problems, do regular water changes and have a few good algae eating fish. One of the best and available is the Ancictrus or bristle nose plecostomus (not reaolly a pleco but sometimes called such since they look similar). Avoid any other plecostomus. They can get to be up to 18" long and can be mean and lazy when they get larger. Mollies browse algae and Otocinclus are good. The best of all is the Siamese Algae Eater (SAE). Avoid Chinese algae eater unless your dealer will take them back when they get large, lazy and mean. Juviniles are OK but I suggest you avoid them. Recent research suggests that algea can be completely controlled by proper fertilizers and light levels (lots of light, use CO2 injection and specially formulated trace element aquatic fertilizer). This research shows that by giving plants all they need for optimum growth they will compete with algae and lock up phosphorus. Algae are starved when they don't get enough phosphorus.

Assuming the tap water contains minimal phosphorus, regular water changes are the best low tech way to control algae. Some water conditioners contain phosphorus. Read the label. Charcoal can remove critical nutrients. Don't use it unless you are removing medication after succesful treatment.

My experience is consistent with the Aquarium Atlas by Baensch when it comes to difficulty level in rearing plants. Stick with the level 1 (easy) plants until you have enough success to try more difficult varieties.

Specific plants that work well for me with hard, alkaline water are listed below. They may also do well in soft acid water. After each plant I have copied the suggested environment range from the Baensch Aquarium Atlas. D=difficulty, KH=carbonate hardness, pH=pH, T=temp in degrees F.

either corkscrew or straight. Medium light requirement, Grows fast and looks good. D=1,KH=5-12, pH=6.5-7.5 (mine grow at pH 8.2), T=59-86F.
Water sprite.
Does either very well or dies out. If it will do well it can take over a tank and is truly a beautiful plant. I suspect allelotropes are involved. Several plant varieties do better with a critical mass and water sprite seems to be in this group. Cryps fall into this category (lots is good category). Water sprite seems to do well in a new tanks and since it grows so fact it is a highly recommended starter plant. D=1, KH=5-12, pH=6.5-7.2, T=75-82F.
Rotala indica (actually R. rotundifolia)
Needs more light but grows rapidly and has a rust colored tint on new growth if given enough light and iron rich fertilizer. D=2, KH=2-15, pH=5.5-7.2, T=68-86F.
Hygrophila polysperma
Durable and needs medium light. Other excellent Hygrophila to try are H. difformis (water wisteria - D=2) and if the tank is large enough, H. corymbosa also known as Temple Plant or Giant Hygrophila. D=1, KH=3-15, pH=6-7.8, T=68-86F.
Most available varieties are hardy. Very slow growing but are worth trying. Need less light. Suggest adding after tank is established. D=1,2 KH=3-15, pH=6-7.8, T=72-82.
Anubias nana
Looks a little like a house plant (ivy). Very, very slow growing but as some say, almost impossible to kill. Very expensive due to slow growth. Get one after you have succeeded with cheaper plants. Can get by on very low light levels and has a tough leaf that most fish can't hurt. There are other anubias varieties available that are larger but share the slow growth and expensive attributes. D=2, KH=2-15, pH=6-7.5, T=64-82F.
Amazon sword plants and most Echinodorus
D=2, KH=5-15, pH=6.5-7.5, T=72-82.
Aponogeton bulbs
Sometimes available at modest cost packed dry with four bulbs for around three dollars. Bulbs grow from food stored in the tuber but that does not mean the plant is storing new food as it "grows". Try aponogeton bulbs after you have had success with other plants. Aponogeton need a resting or dormant period so read up on them before you try them. Or, considering how cheap they are, try them but be aware a rotting tuber can pollute a tank. When new leaves stop forming, remove the bulb and let it rest for two months at 60 degrees or discard. D=2, KH=2-12, pH=6.5-7.5, T=68-79F.
Java Fern
Reported by most plant authors to do well but I have had minimal luck. Slow growing, low light, quite hardy and very pretty. Most fish that eat plants will not eat Jave Fern. D=1, KH=2-12, pH=5.5-7.0, T=68-82F.

There are other specialty plants such as hornwort (Ceratophyllum), and Java Moss that are good for protecting baby fish.

Once you have had success at keeping plants, try some of the more exotic species. Avoid the potted plants sold in fish shops unless you know what you are buying. These may be house plants sold as aquatics. When in doubt, hold the plant where the leaves branch out of the base (the crown). If the leaves fall over and droop on you hand, it is aquatic. If not, it is probably a terrestrial plant. Some of the varieties mentioned above are actually bog plants that do well in a submersed stage (Echinodorus, Hygrophila, Anubias and Cryptocoryne).

As with any endeavor, knowledge will enhance the chance of success. Read all you can. After having success you can go down the high tech road a step at a time. Start with do it yourself carbon dioxide injection by using a brew of yeast and sugar and run the gas into a bell jar made from the bottom half of a plastic 2 liter pop bottle. Upgrade lights with additional fluorescent or replace with metal halide or high output fluorescent bulbs (HO or VHO but they take a special expensive balast). The ultimate is substrate heating and exotic substrate (such as laterite). Each of these high tech steps brings rewards and problems. Keep it fun. Before you move to a higher technical level, understand why you should be doing the "improvement". The main thing you will get with a higher tech tank is much more rapid growth and the ability to keep some of the more difficult species.

Translation to HTML by Erik Olson
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