The low-tech planted aquarium

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With all it entails, the hi-tech planted tank is not to everyone's taste or budget. George Farmer looks at lower maintenance and cost alternatives.

Many of us are leading ever busier lives and in this time of economic uncertainty our hobbies may be taking up less of our attention. I once had five hi-tech planted aquariums running simultaneously, but couldn’t consider that many now as I cannot justify either the time or the expense.

I know other people are in the same position —  yet all is not gloom and doom. We can still keep attractive planted tanks without resorting to the relatively expensive and high maintenance techniques demanded by high-tech planted tanks.

Nano or not?

When choosing an aquarium a first consideration is tank size. Smaller tanks or nanos, aquariums under 40 l/10 gal, are popular, with excellent kits that include almost everything needed to get started. These are perfect for those on a budget and with limited space.  

However, due to their small volume, environmental stability is reduced, so careful stocking and regular maintenance is a must. If you go on holiday regularly, for example, avoid a nano unless you can get someone trustworthy to look after it in your absence.

There is a a greater availability of nano-friendly fish and plants nowadays, but care should still be taken not to overstock with fish. Smaller nanos, of around 10-25 l/2.2-5-5 gal volume, make ideal shrimp-only tanks and a wide variety is available.

Shrimp demand high water quality, so ensure the filter is matured by using fishless cycling before adding any livestock. If you can afford the initial outlay and space then larger aquariums offer more options for stocking and a greater stability.  

Using appropriate techniques, larger tanks can almost be neglected with regards water changes and left to mature with minimal maintenance. This is not really achievable in a nano aquarium as the water may not be stable enough.

Less lighting is more!

Major pruning sessions are required to keep aquascapes in hi-tech tanks in check. Some relish this 'gardening' but for many the time pruning could be better spent elsewhere. If you want slower growth simply lower lighting intensity and/or the photoperiod. However, lower it too much and plants will suffer.

The trick is to stick with lower light tolerant plants. The classic low-light selection include Cryptocoryne, Anubias, mosses, Java ferns and some stems plants such as Hygrophila polysperma and Limnophila sessiflora.  

Interestingly, recent advances in nutrient management, specifically off-the-shelf NPK and liquid carbon products, have made it possible to grow plants once seen as impossible in lower lighting. I have successfully grown a carpet of Glossostigma elatinoides in a 25 l/5.5 gal tank with a single 18w PC lamp and no CO2 injection.

Photoperiods can be cut to as little as six hours and this not only limits growth but your electricity bill too! In larger aquaria you can grow almost any plant with two T5 fluorescent tubes with reflectors, but you will need to add nutrients on a regular basis to help achieve healthy growth.

Lower lighting also restricts nuisance algae growth. The tank is much more forgiving as regards minor maintenance lapses, such as a skipped water change or filter clean. These would otherwise be punished in a tank with high lighting and CO2 injection.

T8 fluorescents remain popular and two lamps with reflectors should be regarded as the minimum for most set-ups. Always use a plug-in timer to ensure a regular photoperiod.

Super substrates

Investing in a decent substrate is probably one of the wisest moves a planted tank owner can make, especially if you don’t wish to rely on religiously dosing liquid fertilisers. Plants with roots can obtain almost all their required nutrients from the roots, so providing them with a nutritious substrate is important.  

Dozens of substrate products are available, from complete products to capsules used to target-feed specific plants — and the March 2009 PFK included a comprehensive substrate review.  

You can easily convert existing plain gravel or sand substrates into a plant-friendly one by inserting tablets or capsules around your chosen plants. Most products will give several months’ supply of nutrients, so represent good value for money.

If intending a major tank overhaul then replacing a plain/inert substrate with a dedicated complete substrate or substrate additive topped with plain gravel/sand is a good idea. Much beneficial bacteria are present in your old substrate so keep some or mix with your new product. Keep an eye on ammonia and nitrite levels to ensure your filter is coping with the overhaul.

CO2 alternatives

Liquid carbon additives have long been popular. They are great value for money when used in smaller aquaria and a 500ml bottle will last almost 12 months in a typical nano. Their active ingredient, glutaraldehyde, is highly toxic but in the doses advised is safe.

These products have a bonus side effect, an apparent algaecide commonly used to treat various algae. However, some 100% aquatic plants such as Vallisneria and Egeria can be sensitive to it, with varying effects depending on the set-up. Overdosing these products is not advised, due to potential toxicity.

When starting out with these products deliberately dose less than the recommended quantity, then slowly build up. I have had great success for a couple of years with regular use of liquid carbon in a number of set-ups from a 10 l/2.2 gal nano to a 370 l/81 gal tank.  

I even did away with CO2 injection as an experiment on a 63 l/14 gal set-up, replacing it with a popular liquid carbon additive.

Dosing is daily and allows the growth of demanding plants such as glosso and Hemianthus callitrichoides without CO2 injection and with lower lighting levels.

If using this product in smaller aquariums it would take several years of regular use to cost more than investing in a pressurised CO2 system and its necessary re-fills. It is potentially safer too, as overdosing CO2 is probably the single biggest fish killer in a planted tank.

Planting

If low maintenance is your aim then best avoid stem plants as these require regular pruning and sometimes re-planting.

Most carpeting plants are to be avoided too as they need frequent maintenance to keep them healthy and to stop overgrowth.

Mosses are generally slow growing in most set-ups but are magnets for detritus and can quickly become clogged with debris, and that can lead to unsightly algae.  

The best low maintenance plants are rosette species such as Cryptocoryne, Vallisneria, Aponogeton and Echinodorus. Of these the crypts are the slowest growing and come in smaller varieties.

Vallisneria, Echinodorus and Aponogeton are better for larger aquaria due to their potential sizes, although there are some smaller Echinodorus species available such as E. tenellus.

Vallisneria nana is ideal for smaller tanks too, due to its finer leaves, but can grow very tall. Vallis can quickly dominate the tank, so remove excess plants by pruning the runners and pulling the desired plants free from the substrate.  

To keep other rosette plants in check remove the desired leaves from the rhizome.  

Other suitable low-maintenance species include those that attach to décor such as Java fern, Bolbitis and Anubias. Fix them to the wood or rocks with zip-ties and simply watch them grow. Then remove unwanted leaves at the rhizome.

What is a hi-tech planted tank?

An aquarium dominated with aquarium plants with plenty of light, water-column nutrients, CO2 injection, nutrient-rich substrate and moderate to high circulation levels can be described as a hi-tech planted tank.  

There can be combinations of all the above and some aquariums will have extras such as LED lighting, substrate heating and pH/CO2 controllers.  

Your benefits are great plant health and growth rates, and the ability to grow any desired aquarium plant — so potentially leading to the most stunning aquascapes. Downsides are relatively high maintenance levels and high initial setting up and running costs.

This item was first published in the August 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.