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Fresh Water Planted Aquariums
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FRESH WATER PLANTED AQUARIUMS Creating a great looking tank brimming with gorgeous plants with hardly a trace of algae in sight is very much attainable. The key is using plants as the filter. With an abundance of healthy plants excess nutrients from fish waste are used up before algae can get at it. And in the process fish will get oxygen they need, thanks to the plants. Consider these guidelines: SUBSTRATE A nutrient based substrate helps plants develop strong roots. Many approaches using commercial products are being used with success. Terralit, a baked clay formula with optimal nutrients added is favored by some because it doesn't cloud the water. Flourite is a quite popular clay product containing iron but is not baked and tends to be dusty which requires a good rinsing before use. Careful installation can prevent clouding. Kitty litter is another clay that seems to work well. Aqua Terra is a gravel additive powder rich in iron and additions of Potash and Magnesium which seems like a good idea. Top soil has a complex mixture of nutrients. Usually these materials are mixed with gravel as the bottom first layer. Two inches of fine grained washed aquarium gravel make the top layer. I've been trying out top soil in combination with a baked illite clay from Aimcor. One form of this material has a uniform fine grained texture and is called Profile. Less expensive is Turface which is similar but has an irregular texture. These soil amendments have a high CEC or cation exchange capacity and holds the ions of ammonium, potassium, calcium and magnesium in a non-leachable form making them available for plant roots. This functions as a nutrient depot. Such a tank has three inches of substrate. The very bottom 1/4" layer consists of medium sized natural aquarium gravel. On top of this is a 1 1/2" mixture of one part Turface and one part top soil. I use an ACE Hardware brand top soil which doesn't contain additional fertilizers. It does contain bacterial cultures. Some would prefer a sterilized soil. The ACE potting soil is just like the regular top soil but is sterilized. The next layer is 1/4" rinsed sand, then 1/2" rinsed Turface. The finishing top is 1/2" fine grained rinsed aquarium gravel. The idea here is nutrients in the soil will migrate to the porous Profile / Turface particles. This configuration tends to prevent excessive leaching into the water column as the tank gets established. Through time the clay releases nutrients as the roots make contact. Prior to filling the tank with water a flat dinner plate is placed on top of the gravel. This serves as a target to disperse the water stream when filling the tank. Some nutrients are likely to leach out from the substrate. After a day I drain out the water to remove the excess nutrients that may exist. This should reduce the chances of an algae bloom that can happen when establishing a new setup. The tank is filled again. If your tap water is hard, adding RO or distilled water in this final stage may be advisable. Our community sits on top of limestone. This means hard, alkaline water. This is not the best for growing aquarium plants. Using the Tetra GH and KH hardness test our tap water reads GH 23 (411.7 ppm), (Very Hard = 18 - 30). KH is 17 (304.3 ppm), (Hard = 12 - 18). Plants do well in our tanks having 1/2 hard tap water and 1/2 RO water. This yields GH-15 (268.5), (Hard = 12-18) and KH 9 (161.1), ( Moderately Hard = 8 - 12). These measurements fair approximations. It is my opinion KH 9 - 10 water is the high end recommendation for planted tanks. As far as the relatively high soluble calcium, actually this might be good for many plants. RO is reverse osmosis, a process for making near pure H2O by pushing water through a tight membrane to yield demineralized water, an equivalent being distilled water. General Hardness (GH) is a measure of the dissolved mineral salts, calcium and magnesium. So called "carbonate hardness" ( KH) represents alkalinity, which is caused by hydrogen carbonates, that is, carbonates and bicarbonates. PLANTS Plant heavily with fast growing quick oxygenating species such as Rotala rotundifolia, Hygrophila polysperma, Cabomba, Ambulia, Vallisneria. As long as the majority of the planting is of fast growers one could also introduce slower more permanent types like Swords and Anubia. Cryptocoryne species might best be planted later because they acclimate better to water that has become more complicated. Hold off on adding liquid fertilizer for about three weeks. It takes this long for plants to get fully acclimated and become efficient at picking up nutrients. During the adjustment period they will do well because they have nutrients stored in their system to tide them over. If liquid fertilizer is added too soon algae will get it and big problems begin. During this break in period add some algae eating fish like Otocinclus and true siamensis. Don't feed them. Let them find any algae that might be around. These little guys are on the front lines against algae. LIGHTING Opinions abound concerning what to use for lighting. Fluorescent units are most frequently used and bulb prices range from $2 specials from discount stores to expensive designer bulbs from most aquarium stores. Inexpensive bulbs tend to have lower light level or lumens and may have a shorter useful life span. An excellent bulb for a planted aquarium is a 5000K Phillips Ultralume with a price of $15 to $20 depending on where one can find them. It has a nice major spike in the warm red and good minor spike in the blue area of the spectrum plus a strong spike in the green which helps deliver the high lumens. Comparing 4' bulbs: An Ultralume has an initial lumens of 3280 with an average life of 20000 hours. In comparison a Colortone 50, 5000K has 2000 lumens with 20000 hours. A utility shop light has 1860 lumens with an average life of 12000 hours. Folks tend to go with what the budget will allow. Sometimes people use a gro-lux type plant bulbs. They experience a lot of algae growth because this type of bulb has a strong spike in the deep red area good for forcing blooms in house plants but notorious for promoting algae in the aquarium. With only about 1200 lumens there is not enough intensity be effective beyond about 4" in the aquarium. Like all fluorescent bulbs a high lumens bulb like Ultralume has a loss of 17% to 20% brightness through time. But even with this loss it still is quite bright and on this basis could have a longer useful life than less expensive bulbs that have low lumens to begin with. As regards to ballasts, sometimes inexpensive ones in some shop light fixtures may burn out bulbs faster compared with ballasts in standard aquarium fixtures. The discussion can be full of variables. If a tank is not deep one may not need the brightest of lights. Some tank strategies have fast growing plants located along the two sides and the back that grow to the top and begin to float across creating a canopy. They get a great hit of light and will create lots a oxygen. Underneath the canopy low light type plants like anubia and crypts will do fine. Perhaps here a lower light level will work. On the other hand the deeper tanks may need more bulbs and brighter ones to help maximize the photosynthesis process for shorter plants requiring bright lighting. My lights are on 16 hours and off 8 hours. The short night period has a purpose with a heavily planted tank having a number of fish. At night both the fish and the plants use oxygen and give off CO2. If the dark period is too long the fish may suffer because of a shortage of oxygen. In terms of fish density and plant mass the variables are too complicated for me know when an oxygen problem will happen. I've done some simple trial and error settings and have come to feel safe with the 16 hours on and 8 hours off. As added insurance some people have an air pump on an appliance timer activating an air stone that kicks in at night to create surface agitation to provide additional oxygenation. CO2 Carbon from CO2 is essential for plants to grow well. It is necessary for creating plant tissue. The most efficient way for plants to get carbon is from CO2. Many excellent filters are designed to oxygenate the water by agitating the surface. This is good for the fish. However, in the process CO2 is driven out of the water column. The result is stunted plants prone to host algae. Traditional filtration strategies promote the nitrogen cycle. Bacteria convert ammonium / ammonia to nitrite then to nitrate which is relatively non-toxic to fish. Aquatic plants can't easily use nitrate. They do best using ammonium / ammonia which happens up front as organic waste begins to decay. Algae is opportunistic and will use nitrate and will proliferate. This causes problems for the higher plants. Plant leaves can't respire well and don't get enough light if algae colonizes on their tissues. Photosynthesis slows. Excess nutrients increase because plants are not using them up fast enough. The system crashes. Submersible filters have the advantage of being positioned easily at various levels below the surface. This way the water surface doesn't break. Having a water current below the surface provides benefits such as dislodging waste particles from the leaves, distributing nutrients throughout the water column and equalizing the water temperature. Finally, the pump sponge located at the water intake captures waste particles. One other small thing will help keep more CO2 in the aquarium. Having a glass top does this somewhat and keeps evaporation down as well. Adding CO2 to the tank can boost the growth of plants and increase their ability to produce oxygen. An abundance of vigorous plant material will leave few nutrients for the algae. CO2 fertilization helps to put plants on the fast track to becoming the tank's primary filter. Using pressurized CO2 with electronic pH monitor and CO2 controller provides for excellent dosing management. This system automatically maintains the right amount of CO2 and pH relative to water KH. The yeast and sugar method is well known and is the prevailing system used by beginners on a budget. After putting two cups of sugar and 1/2 teaspoon of dry granular yeast into a two liter cola bottle add lukewarm water to within three inches of the top. Shaking this up dissolves the sugar / yeast and fermentation shortly begins yielding CO2. Through the bottle cap drill a hole a little less than the 3/16" diameter of the flexible plastic tubing used to route the CO2 gas to the aquarium.. With the help of a small pliers the tubing is pulled through the hole so one inch is inside the bottle. This makes a tight seal. A fine diffuser called an air stone is attached to the end of the line that goes into the tank near the bottom. In this application the stone diffuses CO2, not air. The CO2 will come out as a fizz of tiny bubbles. A limewood diffuser makes nice fine bubbles. A thicket of floating plants above will capture the bubbles where they will integrate into the water. Good floating plants for this purpose include duck weed, ricca flulitan, hornwort and even lilies with floating leaves. The major problem with the cola bottle method is control. Over dosing is a danger. This could suffocate fish. With a hand held battery operated digital pH meter I visit my tanks morning and evening. I want to have the pH between 7.2 and 7.4 in the KH 10 water being used. If the pH hits the high end I put in the tubing with diffuser stone. When the pH hits the low end I take it out. The twice a day check and action pretty much keeps dosing controlled. If I can't pay this close attention for a few days I just don't add CO2 to be on the safe side. A bottle is good for about four weeks. At around the third week the chemical workings in the bottle slow down. Then the distribution stone can remain in for longer periods. At some point what is left in the bottle is alcohol and it is time to make up a batch. If one has KH 9 - 10 water and arrives at pH 7.3 through CO2 fertilization this means the water will have about 15 to 16 mg/L of CO2. This is about right for plants. Fish will be fine. It is important not to add too much CO2. George Booth has an excellent article with good charts that treat this subject in the December 1997 issue of Aquarium Fish Magazine. MAINTENANCE Once things are up and going with the desired fish population it is time to start weekly water changes of about 25%. Using an aquarium siphon to gently remove naturally accumulating debris will help the tank appearance. Plants welcome replenishment of vital trace elements and minerals that come with fresh tap water. When adding new water include some liquid micronutrient supplement containing iron. Use water that has not gone through a water softener. This will provide calcium for plant and fish cell structure. If your community treats the water with a good measure of chlorine, setting aside tap water in open 5 gallon containers for a day or two should allow the chlorine to escape. Chloramine is another story. It is persistent. It can be eliminated by using a good water conditioner such as Amquel, a chemical that does not interfere with the assimilation of nutrients and trace element by plants. As time goes on it might appear that some specific plants need additional fertilization. Iron rich root tabs containing magnesium, potassium and sulfur will give them a boost. Nitrogen and phosphorus may become limiting factors in heavily planted tanks with few fish. Plant tabs with these nutrients should be used also. Liquid fertilizer for aquarium plants is now available that contains nitrogen. One company has added phosphorus as well. If there is no algae problem and some of the plants are looking pale and weak they are saying, "feed us!". And of course, during the week keep a watch on the pH levels and CO2 fertilization process. Each water change presents an opportunity to do necessary gardening. A healthy tank will become robust! Harvest, trim back, take out dying and weak leaves, remove any algae that is beginning and rearrange things as you wish. ALGAE Every keeper of a planted aquarium knows what a pain algae can be. Probabilities are high that algae of several forms will show up in most dynamic aquatic ecosystems. This is all very natural and if the presence is slight this is no big deal. It becomes a crisis when algae changes from a benign presence to an expanding one challenging the higher plants and making the tank look messy. Any challenge from algae should be taken seriously. Quick action is a must, as is figuring out why there is a problem. The main reason is too many nutrients in the water. Some people use forthright action. When attacking this problem stop CO2 fertilization. Remove as much algae as possible mechanically. Scrap it off the glass with a single edged razor blade. Take out decorative rocks and wood and scrub them with course brushes including a tooth brush as needed. Wipe off slime algae from leaves with an absorbent paper towel. Pull out hair algae. Remove leaves with hard dark algae. Take out all dead or weak plant material. Next, do a massive water change. We are talking 90%. The next day, repeat. Then for 72 hours put the tank in total darkness. Make sure you have a way of oxygenating the water by agitating the surface vigorously. The fish will need this oxygen. Without light plants can't make oxygen. When this procedure is complete turn on the lights and do another water change, harvesting any loose algae with a net and siphon. Put in some algae eater fish. They can work at what is left. Siamensis Algae Eaters will go for Blue and Thread Algae. Otocinclus, Mollies, Plecostomus and Ancistrus do good work too along with ram's horn snails, Malayan snails and small algae eating shrimp. If they finish off the algae they will need to be fed with something like slices of Zucchini or Romaine lettuce that is softened by steaming. This deals with the symptoms. If one continues to do things as before, there is a good chance the problem will come back. Reasons for algae attacks may seem elusive. Too many over fed fish causing too much waste would be suspect. More frequent water changes can remove these excess nutrients. Then too, hard water might be a factor. Give a try with planted tank strategies designed to reduce algae problems. See if this makes a difference. GREEN WATER If the water column turns into something akin to pea soup it is a form of green water consisting of infinitesimal organisms. Sometimes putting the tank in the dark will kill off the culture. In one case I have seen, the green water has come back again and again. In the process, difficult to breed fish actually did breed. But the higher plants were deprived of light and started to fail. Doing water changes to cut down on the nutrients seemed to bringing in a fresh supply of nutrients and trace elements that is part of tap water. Then, with the lights coming on and CO2 turned on to help the higher plants recover fast the green water simply exploded again. I have found the tenacity of the situation amazing! It seemed we did all the right things to make the culture thrive. If the fish could be caught and put in a temporary tank, adding daphnia would clear things up in short order. EXCELLENT BOOK Aquarium Plants Manual by Ines Scheurmann, published by Barron's.....Many color photos and a comprehensive orientation for planted tank success. CONCLUSION: If you like gardening you are in for a good time, year round! January 2000 by John Glaeser (608) 233-5182 [email protected]
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