It is possible to have a healthy, low maintenance and visually stunning low tech planted tank without the use of injected CO2, in the same vein that one can make a good cup of coffee without an espresso machine. The coffee will be different, but can be just as good.
If you are setting up a planted tank without injected CO2, these 5 pointers will help:
This low tech tank has been running at the 2hr Aquarist gallery for about 8 months. Besides occasional doses of APT Complete for fertilizer, and weekly water changes, this has been a very low maintenance tank. The substrate is aquarium aquasoil, with easy plants such as Java fern, Anubias, mosses. The short foreground plant is Lilaeopsis brasiliensis.
A shallower tank such as a 20 gallon long or 40 gallon breeder works well. Avoid tall tanks as they are hard to light and hard to aquascape well. Remember that cost balloons quickly with tank size; the cost of a tank is cheap compared to the budgets required for lighting & hardscape. Dedicating a good amount of budget to hardscape is a good idea generally, as it allows for more design choices.
Do plan ahead before over-committing to a large tank.
Small tanks can be great too, head here to see the many benefits of smaller tank sizes.
A medium light level of 30-50 umols of light should work well as a starting point. Having higher levels of light means that there is less leeway in tank maintenance to keep it algae free. Higher light levels do give more plant choices - many carpeting species can be grown without injected CO2 if sufficient light is provided.
Either T5 flourescent fixtures or LED fixtures can work well. Go to the lighting section for more details on planted aquarium lighting guide.
Go for soil
Choosing to use soil/dirt as a planted aquarium substrate gives a much needed boost to low tech planted tank setups. Aquasoils work well but cost more. Soils contain a long term store of nutrients which alleviates the need to manage water column dosing. Most rooted plants grow better in soil. Soil also provides a great habitat for microbes and bacteria. For a more budget approach, using mineralised top soil with a sand cap works well, but is messier to manage.
This low tech tank uses top soil capped with coarse sand. A mix of easy plants such as Cryptocoryne parva, Java fern, Anubias and mosses makes this an easy aquascape to maintain.
Many planted tanks can survive without additional fertilization, but often this is a gamble on soil and tap water supply providing adequate nutrients other than what is derived from livestock waste (which is by no means wholesome unlike what some folks think). This method is unreliable at best - that is why successful planted aquariums are elusive for many rather than the norm. Having a regular fertilization regime has a significant impact on plant health, and good plant health is the greatest defence against algae.
Use an all-in-one fertilizers such as APT Complete (if you have no fish/ livestock) or APT Zero (if you have moderate / high population of fish / livestock).
10X Turnover Filter
Choose a filter with 6X to 10X turnover of tank volume. Next choose outflow/inflows that produces a flow pattern that has sufficient surface agitation and exchange surface layers of water with deeper layers of water in the tank. This improves gaseous exchange in the tank, and directly impacts plant growth.
Finally, if you live in a temperate climate and want to keep tropical fish & plants, a heater may be necessary. 22 to 26 degree celsius is ideal for most planted tanks.
The tank on the top by Cory Hopkins makes use of mainly only 1 plant species - pearlweed (Hemianthus glomeratus).
One does not need a huge variety of plants to have a nice planted tank, what is more important is to choosing species that can grow well without Co2 injection. Design of hardscape and smart mixing of species allows beautiful planted aquascapes with only a few species.
When choosing plants for your tank, be mindful that stem plants grow faster and require regular pruning. Most will grow to touch the water surface. This leads to shading of shorter plants. It is also harder to keep stem plants tidy unless you prune frequently. Growing more rhizomes and other slower growing plants lowers maintenance.
Head here to read on how to grow carpet plants without CO2
Head here to read on how we set up an easy mini low tech shrimp tank