King of Kings: A discus expert shares his secrets


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One of the UK's best known discus breeding and showing celebrities shares some of his secrets to success. Nathan Hill meets 'Chen' of Chen's Discus.

"I’m fish rich," says the man offering me tea in his kitchen. He apologises that it’s not too good — he never makes the stuff for himself. But frankly, I’m too preoccupied with the amazing fish next door to notice. 

As a journo doing the rounds, one name gets dropped around me more than any others in conversations — Chen. Chen’s fish have a reputation of being some of the hardiest and most vibrant selectively bred fish the UK trade has to offer, and I’d be hard pushed to disagree. The lines of tanks that dominate his two fish houses are bursting with all the colours of a dissected rainbow, while curious but sanguine faces press against the glass like greedy carp. His fish are as fearless as they are dazzling.


As a hobbyist myself, and one who has lived through the near-religious fervour of Chen-worship and mystery, I was taken by a stark revelation about the man behind the legend. He’s not called Chen. Francis Hu, Chen’s founder and owner isn’t even entirely sure himself how the name stuck — it was originally his mother’s surname, but beyond that it’s hazy. 

Despite becoming an aquatic legend, he’s as human as I’d hoped. A hobbyist above all else, with a long history of fishkeeping, he’s been around fish his entire life, with a tank of his own guppies by the age of five; he was a precocious fishkeeper. 

"Guppies used to be strong," he tells me. "But now wild discus are hardier than they are." I’d ask him to back up his claim, but he already has by showing me his pristine wild discus happily foraging and spawning. 

In 1994, he started keeping discus for the first time. He had an uncle who’d bred some that same year, and Francis became transfixed by them. He’d venture out with his brother, and they’d be rapping at their local shop’s door at 6am awaiting the new fish, which they’d select straight from the bags and race home with.

He had to hide them from his mother who was against them buying fish, and had them stashed in a side room. One day their plan was rumbled, but quick thinking got them off the hook. "We convinced her that we bred them," he says with a laugh. That simple lie was a premonition of what would follow. 


What started low key as a hobby grew and grew. He insists his interest is breeding and keeping, and downplays any commercial side of his operation. His thing is fish first, business second. 

His main role is as a college lecturer, in a part time and consultancy role. He was full time but cut back to just two days a week to give himself ample fish-house time. 

"It was back in 2002 or 2003, I just had a night-time epiphany,” he says, "and I thought why aren’t I doing discus as a business?

"I had some good Malaysian contacts and started importing them. Then friends began asking me about them, and buying them from me. It grew from there."

A cursory count up of his facilities now puts him at over 80 tanks, from 45cm/18in cubes, up to 150cm/ 60in lumps, spread out on a variety of racks — and a pond. 


A pond for discus

The pond is the most curious thing I’ve seen. With a 500 l/110 gal capacity, and fed by his home-made trickle filter filled with K1 media and foams above, the thing is packed with the compressed, flattened bodies of the fish, yet Francis can tell each and every one apart. I try to round up a number, but there are simply too many. 

This was originally built for stingrays, but is now a gigantic (if well stocked) rearing pond for his show fish. To give a little perspective, this one collection alone consumes around 1kg of beefheart mix every single day. 


Using a long net, Francis deftly hooks out previous winners and up-and-comers, showing me the subtle differences between them.

"Females lack the show-quality blue vibrance," he says, pulling out fish after fish to make his point. "For blues, the males make much better show fish. For red, you want the females."

Pressed on it, he tells me about the beefheart that he feeds profusely to his fish. "I get through at least four or five kilos every day," he says. "It’s not just beefheart though; there’s mussel, spinach, spirulina, flake, prawn — all sorts in there. It’s what I feed exclusively. It’s actually made by Ditone Discus, which I sell," he adds with a grin. "I must sell a good 100–150kg a month right now…

"Discus need big and meaty foods. Giving them anything else is like us trying to live on baby food. And I don’t use bloodworm. That’s bad for discus as it carries pathogens."

Francis puts food down as the second of his ‘big three’ to discus success. "You need good fish to start with," he says, "and then you need to feed them good food. After that you need good water, by which I mean fresh and clean. Don’t get bogged down by obsessing over parameters."


Making a champion

"Traditionally the UK has been seen as bad for discus," Francis says. "But as of a few years ago, we’ve started cleaning up the international contests."

He’s definitely helping to change the UK perception. Last year he journeyed to a Spanish contest and picked up over ten awards for his fish. He turned up with so many different coloured fish they started calling him ‘Rainbowman’.  The year before he only took three fish — and took first, second and third place respectively with them. 

Planning in advance is essential, and Francis has his ideas set up to three years before a show. "It takes 16 to 18 months to get a show fish to grow to a good size," he says. 

Next year he expects some 20 or 30 fish to come out of his pond in show condition, and they’ll be travelling all over; he has contests lined up in Singapore, Spain, Italy, Holland, France as well as here in the UK. With such a predicted winning streak, it’s not surprising that others want to affiliate with him, and Chen even has an alliance with a member of Qatar’s royal family, representing a prince in European contests.


So how does he do it?

Francis secures his bloodlines from Malaysian breeders, when not rearing his own fish. In 2007 he flew out to see them after some issues of consistency — what they thought he wanted wasn’t exactly the case. They listened to what he had to say, and he showed them how he liked fish to be fed, handled, packaged and kept. He instigated protocols and initiated record keeping in every sphere. 

"We’ve got a good rapport now," he says, "and I can ask for fish and they immediately know what I’d like. They steer me away from anything I wouldn’t like. Since I went over, I must have had at least 70 shipments from them."

Key to his success is refusing poor quality fish. Francis has a very clear vision in mind of how a fish should look, but he also knows that if he accepts any chaff then he’s setting up a bad precedent for the future.

"Buy a bad fish and you’ll be trying all the time to recover it," he says. "Lots of people make this mistake, then after a while they give up because of their bad fish, and perpetuate the myth that discus are hard to keep.”

"My first priority is for shape. Discus should be a perfect round shape, or as near as possible to that. Spherical is good. If it’s not shaped like a disc, then don’t call it a discus.

"My second priority is colour and markings. They need to be uniform and intense to win me over.

"The third priority is for eye colour. I prefer fish to have an intense red eye, though not all strains have this." 

This order of ranking varies from nation to nation, it seems, with European breeders placing more emphasis on pattern and eye colour first, then breeding those fish to the shape they require.

"There’s an expectation of good fish that differs between keepers, too. Some like colours, while others are interested in good shape."

Francis has simple advice for those wanting to grow their fish on to show standards. "Water changes,” he says, “are essential for good growth. I aim for at least 50% every other day, and my pond gets a 90% water change daily. 

"Water changes are directly proportionate to good growth and good health, and they’ll fix many major ailments like fish not feeding."


So simple it’s perfect

Despite many people claiming discus to be delicate, demanding fish, Francis uses the barest of essentials to keep his in pristine shape. 

Throughout his multiple racks of tanks, the filtration theme becomes obvious as a simple staple — sponges, wool and some K1 media floating about in trickle towers. That’s as advanced as it gets.

For those imagining his water bill to be skyrocketed by the vast wastage of a heavy-duty RO unit, you’re also mistaken. Everything here is kept in ordinary, everyday Harrow tapwater. 

No cull

"A lot of Malay breeders are Buddhist," Francis says, "which means they won’t cull any of their fish; they’re pacifists to the extreme. Instead they release their inferior fish into lakes. The thing is, there are people the other side of these lakes then catching them out for the hobby. 

"The interesting thing in Malaysia is that only B-grade discus are on sale. All the A-grade stuff is exported."

Discus diseases

With as many fish as there are at Chen’s, hygiene is essential. "There’s a disease out there simply called 'discus plague'," he tells me, "and nobody’s really certain about the diagnosis. But if you get it you’ll have 90 or 100% mortalities. Some keepers testify that it can travel about in the air, but I’m not so sure. Early signs are clamping of fins, darkening of the body, lethargy, refusal to feed, that kind of thing. By day four of infection they’ll be huddled in the corner. It seems to be a mixture of protozoan and bacterial infections.

"I sterilise my hands even after a handshake now, it’s just too high a risk not to. It only needs a drop of water, and that can be carried on a plant, or net, or whatever."

It’s the fear of this illness that has Francis putting all fish through a mandatory one-month quarantine. "If it meets a naïve fish, it’ll go down with it fast. I keep everything under a one-month observation, especially if fish have been exposed to cold in transit. They need time to get fed up and used to the UK water."

He’s wary of another discus killer, too. "It’s usually misdiagnosed as discus plague — the difference is that plague makes your water smell. But velvet disease is nowhere near as bad, with only 20% mortalities or so.

"Internal flagellates need to be watched out for. Fish will stop eating, and become shy. Then they’ll have fluffy white faeces.

"It’s when the immune system stops that the worms cut in — often if the fish haven’t been feeding for a while. But it can also be bad water, bad food, or just an underlying problem in the fish. This is why you shouldn’t buy bad fish.

"Kusuri discus wormer will cure it, but metronidazole is better. You’ll need a vet to get that though. And you’ll still lose quality and not recover all the fish. It’s very reliant on the keeper, and people with good husbandry don’t get it. 

"There’s a big difference between worms and flagellates. If faeces are white and segmented, you have worms, and you’ll need praziquantel. If faeces are fluffy and the fish aren’t feeding, you’ve got the flagellates."

I ask if his customers ever have fish issues. "Not from bad fish," he says, "but from mishaps. I help out where I can though. As I said before, I’m not exactly fish poor.

"Sometimes I’ll raffle off fish for charity. We had one a little while back that raised £600 for cancer research. Others got on side, like CE essentials and Ditone food, and Devotedly Discus. We’re a good community, and I can afford to give the occasional fish away.

"But it is an expensive hobby," he adds."I’ve got a lot of personal fish, and they’re not cheap to maintain."

Taking a last look around, I’m inclined to agree. Francis may have poured a lot of money in to his passion over the years, but on the back of it, he’s not fish poor at all. In fact, a lot of folks would consider him one of the richest men alive…


Want some?

Chen’s prices start at around £10 for a 2.5in hobbyist’s fish, while average 5-6.5in adults command between £75 and £100 each. For show fish or competition calibre fish, prices can sit anywhere between £180 to £900. During my visit, one intense yellow discus priced at £700 awaited collection that day. 

For more details, visit the Chen’s Discus website. His fish are available for both retailers and hobbyists. 

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