David Saxby's ultimate reef tank!


When D-D The Aquarium Solution's owner David Saxby decided to revamp his famous reef tank, we just had to take a look. Jeremy Gay is suitably impressed!

Probably the world’s most famous privately-owned aquarium, David Saxby’s creation is not only huge in its dimensions, at 13,640 l/3,000 gal, it’s also huge in reputation.

It had been some 13 years in its original form before being given a complete recent stripdown and overhaul.

Since its conception the original tank had attracted huge publicity because of its size, the seemingly no-expense-spared dedication of its owner and the success achieved with a vast selection of species.

Up until recently I, like many other people, had only seen David’s tank in PFK, on YouTube and in reefkeeping books. Yet despite never seeing it first hand I felt as if I already knew it. I had seen it so often and heard it discussed so much.

I must have had hundreds of conversations over the years with retailers and hobbyists all over the country, all offering opinions and hearsay about the famous system.

Here now was my chance to ask the questions I always wanted to put to the man behind this remarkable set-up…

 “Can I clear up some of the rumours about your tank?” I asked. “They say that it is worth £250,000, you have team of divers who do the fragging for you, it has split several times and you introduced an octopus that ate everything and then couldn’t get it out again? Are any of these claims true?

“A quarter of a million? Not that I know of”, David replied.  “Yes, the tank has split once, but we are talking of six or seven years ago. The first tank split and a second one had to be made. I’ve made a lot of changes since then.”

“So it did split? How much of a blow was that?”

“It involved a £50,000 insurance claim,” revealed David. “There have been no divers in the tank because you can’t swim in there —and the octopus didn’t eat everything in sight!

“I had to have it because when the tank was first set up I had Red Sea live rock and hundreds of Mantis shrimps in it. I put the octopus in when small. He only ate a couple of fish and I fed him chicken — but then there were no more shrimps to catch

“He’d got 99% of them so I wanted to take him out because he got quite big, but I couldn’t find a way of catching him. In the end I went to Brighton and got a couple of crabs, tied a string around them and dangled them in. He got straight on and I grabbed him.”


Seeing this tank in the flesh was another dream come true. We don’t often visit reef tanks that are truly breathtaking, but this reef has four fabulous features: size, variety, colour and movement.

For me the best aspect was colour and David said that when he redid the tank he wanted to focus that very feature.

He always had tremendous colours with his fish, but this time wanted intense coral colour too, switching over time to an aquascape he says is predominated by colourful SPS corals — and even switching some high power metal halides lights to some 40 linear T5 tubes. Yes, 40!

The movement and variety of fish and corals make up an incredibly rich display. It might not be a natural representation of a particular area or zone of a reef, but looks really good. It’s one heck of a spectacle.

New aquascape

I made constant references to David’s tank of old, as that is the one I grew up reading about. Yet this is an entirely new tank which had had been running for just 11 months, prior to our visit, following the stripdown.

David recalled: “Due to a serious family illness I didn’t bother about the tank for three months. That was the reason I stripped it down and started again. After that I thought I would have a fresh start.”

I asked how long it took to strip down and if all of the rock had been removed.

“Four or five of us did it in a day, “ he remembered. “I got Mark, who does my tank maintenance, to help. He’s very good. First class. I took all the rocks out, spray cleaned them and left them outside for a week. I tried to kill everything that was on there too."

I noticed fewer fish than there used to be. Old pictures showed adult Pyjama tangs and a much sought after Black longnose tang. Now all the fish seemed younger and in place of the longnose was an even more valuable Gem tang, (Zebrasoma gemmatum).

“Some died from shock very soon after being removed from the aquarium,” said David. “I did have a Black longnose but you can’t keep them in there with a Gem tang as they fight. The Yellow tangs and Scopas tangs are not a problem with the Gem tang."

While watching a video of David’s tank prior to my interview, I noted some unusual morphs of some tangs. Known as Tri-colour tangs, these are Scopas tangs that unusually display patches of black, white and yellow on their bodies. Many people would like to get their hands on his collection.

“They are not that rare and I find that quite extraordinary,” added David. “I have several and one is just starting to get his black back. I never paid more than £70 or £80 each. I got stung for one once, but that was a long time ago.”

The fish are all extremely healthy and well fed. Quite a few are breeding. Some difficult species, including Cleaner wrasse, dragonettes, pipefish and anthias, are doing really well. There are jawfish in the substrate too. We counted at least five species of anthias and I asked David if the yellow tangs, in his large shoal, had ever bred:

“They haven’t bred but the Yellow tangs do something that’s very strange. Every so often, and this takes two or three years, they will pick on one en masse and kill it. Then they will pick on the next one and kill that, until only two or three are left.

“I’ve had that happen twice and when I see it begin I catch three- quarters of all the tangs and rehome them, starting again with small ones. I lost six or seven before I realised I had to do something about it. Quite strange behaviour!

“Bernie Mohr, the German reefkeeping expert, told me about it first and I didn’t believe him — until it happened to me.”

The aquascape

David has done a fine job of hiding all the pipework. We really like the live rock atoll on the left hand side of the tank as you view it from the front. It’s huge, looking like a dead coral colonised by new ones growing on top of it.

The huge structure that dominates an area of some 1.2m/4’ cubed, came as one piece, according to David, and, when unpacked, had been shipped along with two Morays eels living inside it – one alive, one dead.

All the corals are stunning. The LPS, SPS and the groups live and grow together, adding to the overall display. Lots are grouped to produce a display within the main display, and those combined with the ‘L’ shape of the tank, and those subsequent three vistas mean you can simply sit or stand for hours just watching and exploring the stunning aquascape.

Of the LPS corals the Trachyphyllia were particularly stunning and had been grouped together at one end of the ‘L’. I noted several Red goniopora and asked how David succeeded with the genus when so many fail?

 “They are easy,” he replied. “Red ones are much easier than green ones. People fail because they have too much phosphate which is a key factor with Goniopora. Alveopora are easier still.”

I asked David what he thought of all the publicity surrounding his tank, and if it still ranked so highly in terms of quality when so many other reefkeepers are now having similar success.

“It’s been very well covered because it was a very early success, “ he said. “I’ve seen some better tanks than mine, not often, but I do see them. I saw a 1.2m/4’ one last week that was just incredible.”

Battling pests

It was refreshing to see that even this tank suffers from nuisances that also affect us mere mortal fishkeepers.

On our visit David was battling Aiptasia, planarian flat worms, Pyramid snails which were attacking his clams and another nuisance anemone that looked similar to Manjano, only larger. “I normally put a Copperband in to eat Aiptasia, but unfortunately Copperbands also eat Acanthastrea,” he said. “I’ve got a Filefish in, which is under experiment, along with a lot of Peppermint shrimps.”

Because of the tremendous stability of the system and the number of corals and fish housed as potential hosts, David is constantly having to control pests.

Stuffed between some rocky outcrops on one of the vertical rock walls was black, plastic gauze. This, said David, was his latest method for controlling the Manjano-like anemones.

The idea is for them to climb onto or grow through the gauze, only for David to take it out, removing the pests with it.

Those, he said, had the potential to be a real problem if unchecked.

The large impressive clams were sat raised on acrylic collars and David was protecting them from Pyramid snails feasting on their mantles at night. The thinking was to enable his wrasses to get underneath them and predate the snails.

There were also some black and blue nudibranchs he used for planaria control on the tank’s mushrooms.

Vital statistics

Aquarium size: 3 x 2 x 1.5m/10 x 6.6 x 5’ (L-shaped) 1.2 m/4’ deep.

Volume: Main display aquarium, plus massive amounts of filtration, totalling 13,640 l/3,000 gal.

Filtration: Several large protein skimmers, plus more than 1,016 kg/1 ton of live rock. Two nitrate reactors and copious amounts of phosphate remover are used.

Circulation turnover: Fourteen times tank turnover per hour, though 2 x 11,000 gallons per hour are also constantly being pumped to and from the tank via two 0.75 horsepower pumps.

Lighting: Several high-powered metal halide lights, plus more than 40 T5 tubes.

Other equipment: Three computers for total automated control. Two large refrigerant coolers, one 2,000 l/440 gal per day RO unit. Nitrate reactors are dosed with 60ml/2.1oz vodka per day, each. Caulerpa algae bed in flow through reservoir. Automatic water change system.

Counting the cost of the tank

  • The water in David’s tank is probably worth more than your entire set-up. The 477kg dissolved within its 13,640 l/3,000 gal is worth over £1,055. A 10% water change once a month would cost you over £100 in salt alone and over £1,200 a year.
  • David adds the equivalent of more than three bottles of vodka to the nitrate filter every month. That’s 31 bottles every year – or over £300 spent at the local supermarket on booze for the bacteria.
  • There’s a ton of live rock in the tank. If you bought it by the boxful at a retailer, this would set you back a wallet-busting £10,160, though we’d imagine David would get a healthy discount for buying in bulk!
  •  The tank’s pumps turn over more than 191,000 l/42,000 gal of water every hour. This is enough to fill a bathtub in just five seconds.

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