SINGAPORE - Five years ago, a glance at a colleague's computer screen caught electrical engineer Robertus Hartono by surprise.
What he saw was a beautiful landscape - an intensely emerald forest, with lush leaves undulating as though in a breeze. Yet, fish were darting between the branches. It was completely underwater.
The colleague said that the image was of a planted tank, a freshwater aquarium where the focus is not on the fish but the aquascape inside.
"I saw the beautiful aquascaping and thought it was amazing. I just jumped into it," says Mr Hartono. The 38-year-old Singaporean set off at once to buy a tank to start his own planted aquarium.
Since then, after a couple of years of trial and error, he has won awards here and abroad for his planted tank designs.
At the biennial Aquarama International Ornamental Fish and Accessories Exhibition here this year, he and his partner - Mr Siak Wee Yeo, 30, a network administrator - won first place for their planted tank, and first and third place for their nano tanks which are about 30cm square.
Of the aquascape's appeal, he says: "It brings nature into the home. It's beautiful, relaxing and very serene to look at. It's living art."
While it is still a niche interest, hobbyists such as Mr Hartono have been plugging away for years at aquascaping, with an estimated 3,000 members active on forums online such as AquaticQuotient.com.
Log on to Aquatic Quotient and you will find posts from enthusiasts sharing aquascape designs, information about plants, and giving advice and encouragement to newcomers.
When the forum started in December 2001, it had about 140 members. Since then, it has attracted an average of 90 new members each month.
These days, the website has 13,000 members, about 2,000 of whom post regularly.
Like Mr Hartono, many planted tank enthusiasts - they prefer the terms "aquarists" or "aquascapers" - are inspired by Amano Takashi's work.
The 59-year-old Japanese landscape photographer is credited with developing the nature aquarium style of planted tanks in the 1990s, creating minimalist scenes inspired by the rocky mountains of Japan or dense Amazonian jungle.
His aquascapes are sometimes Zen, sometimes verging on the surreal.
For some aquarists, such as interior designer Michael Lai, aquascaping is a natural progression from rearing fish as a hobby.
"A planted aquarium is like underwater architecture," says Mr Lai, 44, who started designing his own planted tanks 10 years ago but still keeps a separate tank of six stingrays.
"It's a different fulfilment from keeping fish. To do it correctly is not as easy as having a normal fish tank. You have to think of design principles, such as depth of field and focus, proportions, mixing and matching the plants," he adds. "There's a method to the madness."
Unlike the larger, more colourful, patterned and exotic fish that some fish lovers populate their tanks with, aquarists favour small fish - only a few centimetres long - that swim in schools, so as not to distract from the aquascape.
But Mr Vincent Phua, a polytechnic lecturer in information technology who has designed planted tanks for almost 15 years, says the fish are also an integral aspect of the tank's health.
"A planted tank is a mini ecosystem. The fish waste becomes part of the nutrient system for the plants, then the plants will produce oxygen for the fish," says Mr Puah, 41, who is also one of the administrators of Aquatic- Quotient.com.
Do not be fooled. Enthusiasts say that setting up a planted tank is much more difficult than it looks. It is more than just arranging aquatic plants in water and then releasing a few fish.
Each tank requires a careful balance of nutrients, carbon dioxide and light, and the correct water temperature for the fish and plants to thrive within. Too many nutrients or too much light, for instance, can create an algae bloom, causing the fish and plants to die.
Newbies to the hobby, such as office administrator Rachel Teo, 31, often struggle with these variables. She has had her 60cm-long planted tank for less than six months.
"At first, everything took turns to die. I couldn't understand why," she recalls.
With advice from enthusiasts from Aquatic Quotient forum as well as her fish-rearing boyfriend, she was able to stabilise her tank after two months.
Hobbyists need equipment such as a filtration system, a carbon dioxide pump and lights. An entry-level tank system costs about $200, but higher-end gadgets can cost thousands of dollars.
Web designer Grape Wongsongja has been dabbling in aquascapes for the past three years and started her newest aquascape, a Zen mountainscape in a 60cm tank, a week ago.
She spent about $2,000 on the equipment, all from Amano Takashi's brand of products called Aqua Design Amano.
"Whatever I have from my salary, I pump into the fish tank instead of buying bags and shoes," says Ms Wongsongja, 27, adding that the money spent is worth it.
"It's peaceful. When you see it, it takes you to another world."
Maintaining a mini eco-system "takes a lot of time and patience", she admits. "You have to be meticulous."
It takes a few weeks to a few months for the plants to be fully grown and for the scape to reach optimal condition. The aquascaper must trim the plants every few weeks to maintain their desired size and shape.
If you want your own aquascape but do not want to devote the time or energy to designing one, you could turn to companies such as Green Chapter, which specialise in planted tank design.
Each tank costs about $1,500 per foot length of the tank. Green Chapter, which opened in 2004, also holds planted aquarium workshops. It costs about $500 for a two-hour session.
Green Chapter creative director Stan Chung, 44, says: "A planted aquarium is like having a bit of nature in your living room. It's very pleasing to the eye, all green and small fishes. I find it calming and soothing, like you are immersed in nature, in silence."
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