By Bob Jones, BAS

This monthly diary (A Breeder's Tail) is from the BAS members' newsletter; written by one of UK's most prominent goldfish breeders, it presents a thorough guide to the annual routine of goldfish breeding. The majority of the information is from 2014, with supplementary information from the years 2015-17.

The information in this article is ordered by the time of year in which the activity takes place; please see Conditioning, Breeding, and Raising Fry for a sister-article with the information ordered by topics.

This article contains detailed information on the typical numbers of fry produced from goldfish spawnings, and of the culling process undertaken to select the young fish which are the best of the brood to be retained for showing in competitions and breeding in future years.

The major cause of failure in goldfish breeding is polluting the water through overcrowding and/or overfeeding: regular culling and giving the young fish enough space to grow healthily are essential. See the Summary at the end of this article for an illustration of the proportion of each spawning (of twintails) that is culled and the large amount of tank space given to each young fish for growing-on to adulthood.


fish house

Fish house and ponds

What do you do at this time of year? Well, if you take my advice the answer will be very little.

I must say I always try to put my feet up and have a break from the fish for a couple of months. I defiantly believe that in doing so you approach the new breeding season with renewed vigour and enthusiasm, and if truth be known the fish could do with a break from me also.

I do ensure, however, that going into the winter the fish are in good condition and the ponds or tanks are clean and the water quality good. I do stop feeding them around mid to late December, depending on the temperature, which means they don't have any food for around two months or so, except what they find naturally in the ponds.

I tend to over-winter all my fish outside (except for my calico veiltails and moors, which I bring in when it’s really cold). During early December, after the leaves have fallen, I trim back all the pond plants and water lilies in the ornamental pond. I make sure the ponds are clean, the water aged and treated to get rid of any chlorine, etc., and when the water temperature equalizes out they go, from the tanks in the fish house into the ponds. I also make sure the ponds are securely netted as a barrier against those ‘lovely’ herons, and other predators. I firmly believe this leads to the development of hardy strains, something we all should try to achieve, as weak fish make very poor breeders and will (if they are not eliminated during the winters outdoors) inevitably pass that weakness on to their offspring.

I set about cleaning all the tanks in the fish house. This is a must-do job every year, as I like to have all the tanks clean and dry over winter just to make absolutely sure no parasites have survived to give me trouble the following year. I don't know why, but I've been very lucky for many, many years now as I've not had any flukes, white spot or any other problems with my fish, so I guess I must be doing something right. For the next couple of months I leave the fish alone; I don't feed them at all, just let them slow down and hibernate through the winter. I keep my eye on them of course, just to make sure all is okay. I like to have a break myself through the winter, catch up on all the jobs in the house and watch some football, of course. I find this little break re-motivates me and then when spring comes, I'm raring to go.


I normally leave all my fish outside during the winter months as I’m convinced this leads to the development of a hardy strain, and my calico veiltails and moors will be brought inside when it’s really cold. But in 2015, in the middle of January, I decided to bring some of the other fish inside; I brought in some Bristol shubunkins just to get a head start on the breeding season.

In February 2015, I couldn’t wait any longer, I just had to get the fish into the fish house and start the conditioning process; the date was the 14th of February! I brought all the fish in that I might possibly use, and as the days/weeks go by I’ll remove the fish I definitely won’t use for breeding, and place them back into the outside ponds again.

I hope to breed 5 different varieties this year, namely Bristol shubunkins, veiltails, fantails, moors and common goldfish (the goldfish are for restocking the pond).

Fish house in February 2015

Fish house in February 2015, with selected fish brought in from the ponds
for an early start to the breeding season


I usually start the breeding process in March (although in 2015, as just described above, I started early). So, on 1st March 2014, it was time to get those lovely clean tanks full of water in readiness to condition the potential breeders.

I give all the empty, dry tanks in the fish house a wipe over with a damp cloth to get rid of all the dust and dead spiders, etc. I then fill the tanks with water from the ponds that the fish have over-wintered in; this ensures the fish don't suffer any stress by being transferred into different water. They will suffer some stress just by moving them, but this will be minimized by placing them in the same water that they're used to.

Before I move the fish I put a 300 watt heater in every tank in readiness for when I'll start slowly increasing the water temperature. This I'll do after a day or two, once the fish have become acclimatized to their new quarters. As an added safeguard I don't feed them for a day or two, no matter what the water temperature is.

fish house female veiltails

Clean fish tanks filled with pond water

Three female veiltails, just moved
back into the fish house

Now the moment has come, I collect the fish in buckets from the outside pond and place them in the tanks, trying to sex them as I go. The males go in the top tanks and the females in the bottom. I keep the different varieties separated in their own tanks. As the next few weeks go by you will notice a few females in the male tanks and vice versa, so they must be rehoused in the right tanks. I always separate the sexes when I'm conditioning them.

When that’s done and the fish have settled down, I treat them to kill any parasites, the main one being flukes. In previous years (up to and including 2014) I have used formalin and malachite green, and for many years, especially in my early days of fishkeeping, I used Dettol. This was very effective but also very hard on the fish; I don’t use it anymore. This year (2015) I used Fluke-Solve by Vetark; the main ingredient is praziquantel which is very effective in killing flukes, but the real beauty of it is the fact that it’s very kind to the fish. I left the fish in the solution for 36 hours. During this time I kept the running water turned off and didn’t feed the fish. Not feeding them keeps the water in good condition whilst the fish are being treated. After the 36 hours I turned on the running water and slowly commenced feeding with low-protein Wheat-Germ pellets.

The water temperature in the tanks will be around 50°F (10°C) when I move the fish inside. Over the next week I will slowly raise this to 62°F (16.7°C). I do this by using timer sockets; they are calibrated in 15 minute segments. First I have the heater on 15 minutes every 1½ hours, then every 1¼ hours, then every 1 hour. After a week they stay on all the time on the lowest thermostat setting.

After a day or two I start feeding the breeders on pelleted (dry) food. I do this for three or four days; it's light and gets the fish feeding. As the water warms I move on to Hikari Gold pellets, expensive, but I believe it's the best food out there. I will also start giving them Dendrobaena worms; I breed them myself but I also buy some in, mail order at around £15–£20 per kg. They are also fed bloodworm and tadpoles if they show they have the appetite.

I will condition them (using this feeding regime) for 3–5 weeks and look to spawn them from early to mid-April. During this time I constantly syphon the tank bottoms and keep the front glass clean.


golfish spawning in mops

Goldfish spawning in mops

From the middle of March to mid-April, I have been feeding up the breeders; I started with pelleted food, and then moved on to Hikari Gold. I also feed daphnia, frog tadpoles and Dendrobaena worms. During this period I remove all the pond nets and clean out a few of the ponds. I trim or replant some marginal plants, feed all the water lilies, and do all the other fishy jobs that need doing at this time of year.

Back in the fish house I decided it was time to start breeding, so I filled eight tanks with treated water (treated to remove the chlorine from tapwater) and left them overnight to stand. The next day in went the spawning mops and the temperature was set at 65°F (18°C). I carefully selected the fish and in they went, two tanks for veiltails, two for Bristol shubunkins, two for fantails and two for moors; I aim to use one or two females and three or four males in each tank (if I can). I don’t feed them, or feed slightly less, maybe, until they spawn.

I always let them spawn naturally at first, and then I hand strip; I do this in a white washing-up bowl and then place the bowl in the tank with an air stone bubbling just in front of the eggs. On the 18th of April the moors went; it was a very good spawning. On the 19th the veiltails went, on the 21st the other tank of veiltails went and on the 23rd the shubunkins went. (That's all the spawnings so far, as of writing this in 2014.)

eggs 12 hours before hatching fry 12 hours after hatching 3-day-old fry

Eggs 12 hours before hatching

Fry 12 hours after hatching

3-day-old fry

After spawning, I raise the temperature to 70°F (21°C) so the eggs usually hatch in three days. They then spend 2 days hanging on the glass or the mops, feeding off their yoke sacs before they become free swimming and start looking for food. On that day I feed them on soaked Hikari squeezed through a handkerchief so it forms a minute dust cloud. The following day they go onto brine shrimp.     

The fantails, one tank of moors and one tank of shubunkins have not spawned yet but that's because I chose the crosses I wanted and not just the fish that were ready to spawn. Hopefully, they will go soon. I have also set another tank of shubunkins and another tank of veiltails ready, just in case.

As I type this, the moors (the first spawning) are on brine shrimp and I can already see their little red bellies.

I've just been looking at the veiltails I bred last year and I'm quite pleased with them. They are being fed on Hikari Gold and daphnia as it's my intention to breed them next year if all goes well (Ha, famous last words).


It is now approaching the end of May and I'm bitterly disappointed that my metallic fantails haven't spawned. This is the first time (2014) in over twenty years they've not produced for me. On the other hand, my calico veiltails just won't stop breeding. In fact, I haven't taken any of these later spawnings, I've just let the fish eat the eggs as they do in nature.

The moors bred on the 18th of April, a very good hatch of maybe 4,000 young. Then just after, came two spawnings of calico veiltails; the first produced around 1,500 young and the second around 3,000. My Bristol shubunkins then went but they only gave me 300 young, which was another disappointment, but I guess you can't win them all. So that's it this year, four spawnings.

First cull of veiltails

2-week-old calico veiltails 2014

Two-to-three weeks old calico veiltails

I started culling at the beginning of May when the veiltail fry were two or three weeks old. The first cull is for selecting the calico fish. In a calico cross, 25% of them will be metallic and 25% will be pinkies with black eyes (both of these types are discarded, by the way), leaving 50% which will be calico. At the same time I look for clean, square tails and decent dorsal fins. These are the fry I keep which usually works out at around 30% of the fry I started with.

This culling is done side on, and I use a narrow tank filled with only three inches of water (see picture below) as it's very easy to see the fry, especially when using a magnifying glass as they all stay in focus. Plus, it's easier to catch the fry that you intend to keep. I place around 20 fry in the tank and with a small plastic tea strainer lift all the good ones out, one by one and gently place them in a container (I use an empty ice cream tub for this). What's left in the tank I discard; I just net them out and they go into a bucket. When I release the good ones back into the tank, I quickly count them as they swim out of the ice cream tub. It's useful to know roughly how many fry you have in each tank, so you can divide them to have the same number in every tank. Assuming you have several tanks of the same spawn, each tank can then be fed the same amount of food and cleaned or siphoned out at the same time. Another big advantage is that the fry will all grow at the same rate.

First cull of moors

When I finished the first veiltail cull I moved straight on to the first cull of the 4,000 moors, something I was really looking forward to, as you can well imagine.

For this first cull I view them from above (overhead), and I select all the fry with split tails which are also well spread and without obvious defects. This reduced the numbers down to around 2,000 (50%).

culling tank culling 2-week-old fry

Culling tank

Culling 2-week-old fry

I have tried using many different containers for this overhead cull, including enamel bowls, washing-up bowls and various tubs and pots, but the best one I have ever found for doing this job is the one in the picture above. It's a small, cut-down plastic bucket which is 23 cm in diameter and 12 cm high. It's small enough that the fry don't go swimming off in every direction and big enough to hold 20 or 30 at a time and still be able to select them one by one.

Second culls

I then went through all the baby moors again, but this time with the small glass tank. I looked for fry with clean square tails, high dorsal fins, and backs with a good contour, and also having a good depth to the body. This narrowed them down to 370 (9%).

I then did the same thing for the veiltails on their second cull. First of all, overhead to select split tails etc., then, with the glass tank to select for square tails etc. This got them down to 490 (11%).

Tanks used

My glass tanks measure 150 cm x 45 cm x 30 cm deep (60 x 18 x 12 inches deep) and with 25 cm depth of water they hold 180 litres (40 gallons).

I now have 7 tanks of veiltails with 70 in each tank (490 youngsters in total) and 5 tanks of moors with 74 in each tank (370 in total).


This time of year seems to me to be one of the busiest, with more culling, constant feeding, and regular, almost-daily syphoning of the tank bottoms to keep the water in good condition and to avoid any build-up of toxic wastes as young fish are so vulnerable to any pollution. I keep the front glass clean so I can see the fish, but leave the sides and back to become green with algae. I believe this is more natural and it keeps the water in better condition.

On the culling front, earlier this month I culled for double anal fins, discarding all those fish with only one fin. This can be a very difficult job, as sometimes the double fins are very close together, and it will look as if there is only one fin, so you have to be really careful not to throw away good fish. I normally find that around 70% of my young fish will have good double anal fins. At the same time I look out for other faults that I have missed or that have developed since the last full cull.

I am now left with around 200 baby veiltails (4%) and 180 moors (5%), which are currently spread around 14 tanks, each tank holding 180 litres (40 gallons) of water (as already described).

The fish are now 2.5 cm (1 inch) in length and are growing really fast.

Flukes!!! You've got to be kidding, right? (A cautionary tale)

I have recently purchased some fish from within the hobby; I brought them home, and put them in a clean tank that had been empty and dry for several weeks. The water was mature, de-chlorinated and treated with tap water conditioner. I had an air stone running and never fed them. Oh, I forgot to say, they never came into contact with any of my fish, I think they call that 'quarantining'.

Anyway, the next day I noticed two of the fish were very quiet and were hanging near the water surface; strange, I thought. The day after I noticed one or two of them were flicking (showing signs of irritation in the gill area), so I did a 50% water change to see if that would make any difference: it didn't. I have my own microscope, so, this morning, out it came and I took a body scrape just behind the gill covers, and with the microscope set at 40 x magnification there they were, flukes! Flukes so big they could go to work. Twenty minutes later the fish were in formalin and malachite green at a dosage of 1 ml to 45 litres (10 gallons). Formalin reduces the oxygen in the water, so I increased the aeration; you need to be so careful about this. I will re-dose after 3 and 7 days.

Now remember, you must, always, Quarantine, Quarantine, Quarantine.


I mentioned last month that I bought some fish, and when I got them home it turned out they had flukes. Anyway, I gave them a long term bath in formalin and malachite green at 1 ml to 45 litres (10 gallons). Then, three days later I re-dosed, and three days after that I re-dosed again.

As the fish came from a different part of the country, with different water parameters, they were not taking kindly to being immersed in formalin and malachite green, as well as the different water. Formalin is rather caustic and can damage the delicate gill membranes, bearing in mind that they are already damaged by the flukes. My fish were breathing heavily so I decided enough is enough, it’s no good killing the flukes if you’re going to kill the fish as well.

I researched and found another product that would kill the flukes and would be a lot kinder to the fishes’ gills. The product is called Fluke-Solve. The fish have been in it now for two weeks and the flukes have gone, and the fish are just fine. The magic ingredient in Fluke-Solve is praziquantel.

I continue to feed this year’s young every couple of hours with mashed up Hikari Gold and daphnia. All the tank bottoms are syphoned on a daily basis to remove any droppings and debris. All my adult fish are now outside in ponds, and the only fish in the fish house are this year’s young and last year’s veiltails which are housed in a 183 cm x 61 cm x 61 cm (6 x 2 x 2 feet) tank (see photo).

year-old veiltails

Year-old veiltails


Since the last newsletter I’ve had no reoccurrence of the fluke problem I had a couple of months ago, so I think I can put that episode behind me now. I’m only grateful that I quarantined the fish in question and it never spread to my other fish, including this year’s young. I can’t stress enough the importance of quarantining any new fish, or plants for that matter. It doesn’t matter where they came from, even if it’s from a trusted source, you MUST keep them separate from your other fish for at least two or three weeks and preferably longer.

On the fish front, I continue to feed the young every couple of hours. I think it’s important to keep them eating. Their staple diet is mashed up Hikari Gold and daphnia. I make sure I only feed enough Hikari Gold to last half an hour or so in the tank; that way you don’t pollute the tank. No such problem with feeding daphnia as it’s a live food. I’m lucky as I keep ducks and they have their own duck pond which measures 35 x 12 feet (10.7 x 3.7 m); this pond is also teaming with daphnia so I nearly always have a good supply of live food for my fish, not to mention duck eggs for my own breakfast.

I make sure I remove any debris in the tanks by syphoning the bottoms every other day. If necessary I’ll do it every day. After syphoning, I clean the front glass with a sponge so I can keep my eye on them at all times.

I have now done my final cull, so I am left with only reasonable quality fish. The discarded fish from this culling are sold or given away to friends; none of them were, shall we say, ‘dispatched’.

I am now left with 20 Bristol shubunkins (which I am not content with) (6½% of the original spawning of 300 fry hatched last May), 40 calico veiltails (0.8% of last May's spawning of 4,500), and 50 moors (1¼% of the 4,000 spawned last May). The veiltails and moors are kept 10 to a tank: with my tanks being 150 cm x 45 cm x 30 cm deep (60 x 18 x 12 inches deep), that gives 340 square cm (55 square inches) of surface area for each of the young Bristol shubunkins and 135–170 square cm (22–27 square inches) for each of the young twintails. I believe it’s very important to give the young fish as much space as possible; that way growth rates will be good.

Our show is only about a week away, which is quickly followed by NGPS and the new Nationwide Show, which is at the end of the month. So over the next week, I will be selecting the fish that I will be showing. I will show adult fish, and also this year’s young. The young will be shown singly and also as teams of four. We will at last see just how good they are.


golden orfe

Golden orfe

The first week of this month has been taken up with our show; I’m the show secretary and there is always plenty to do leading up to the big event. Apart from feeding the fish and keeping the tanks clean, I never did any fishy stuff until the 10th of September. I always put my show fish in tanks after the show so I can easily get them again for the upcoming NGPS and Nationwide shows. As a rule I tend to show the same fish especially if they have managed to get a card.

On the 10th and 11th I cleaned all my tanks; they hadn’t been cleaned for several weeks, so it was a job that was long overdue. Every time I clean the tanks I notice the colour of the fish go pale. This is quite natural as they don’t have the green gunge to browse on and they are surrounded by transparent class. This is the reason that you always use black buckets when you take your fish to a show, as the dark black bucket improves the fishes’ colour at this important moment.

The weather is unusually dry and warm, so I have taken the opportunity to clean some ponds and also my duck pond.

I have four ponds that measure 17 x 14 feet (5.2 x 4.3 m) and are around 2½ feet (0.75 m) deep. I used these to grow water lilies, which I used to sell and although I still have many lilies I haven’t been selling them for several years now. One of these ponds is home for well over 100 golden orfe. I’m very fond of orfe as I think they make a great pond fish. They’re a shoaling fish and always swim close to the water surface, so they are always in view. They must have good water conditions but on the whole they are quite easy to look after.

Every now and then I alternate these fish between two adjoining ponds, which is the easiest way to do it. I clean, fill and treat the adjoining pond then drain the pond with the orfe in. As the water goes down, maybe with only 3 inches (7.5 cm) of water left, I pick up the fish and place them in the clean pond. I then clean the pond and leave it empty and dry. All my ponds have sloping bottoms with a sump at the lowest level, so I am able to drain every last drop of water. Cleaning these ponds takes me the best part of a day.

duck pond

Duck pond


Every year around the end of October, or early November, all my fish go outside for the winter, both adult and young alike. I’m a strong believer in not mollycoddling the fish over the cold period, as this will lead to hardy fish, and likewise the development of a hardy strain that, in turn, will be able to withstand the cold conditions in future years. I also like to empty the fish house and leave the tanks dry for a couple of months to get rid of any parasites. As I’ve had a few problems this year with flukes etc., I decided to do a deep clean this month.

First off, I cleaned all the tanks, troughs and the trough filter. When everything was clean I refilled with water and dosed with potassium permanganate (permanganate of potash) at 10 mg per litre. As the whole system held 6,800 litres it equated to 68 grams. This turned the water deep purple. As my fish house is a circulating system I turned on the pump so all the pipes etc. were also treated. I did the treatment during early evening as daylight will biodegrade the permanganate. I left this in the system for 24 hours. I then drained all the water and swilled it through. I then refilled the top tanks with tap water and dosed them with bleach using a 15% solution; I used 180 litres of bleach in all. I left the top tanks to soak for 12 hours.

I then very carefully syphoned this bleach water down into the bottom row of tanks. This was also left for 12 hours.

The bleach water was once again carefully syphoned down into the troughs and filter and the pump was turned on. So I was able to pump the water around the whole system, thus disinfecting all the pipe work as well. After 24 hours I drained the system and flushed with tap water. I then cleaned the tanks again to make sure all the bleach was removed.

All my tanks are now bone dry and this is how they will remain for a couple of months. Bleaching the filter will kill ALL the bacteria so I will have to be careful when I restart it, for it will take around 6 weeks to re-establish any filter bacteria. Before the fish go back into the fish house I will run fresh water through all the tanks etc. once again.

soaking in permanganate bleach
soaking in bleach clean filter


tub of daphnia

Tub of daphnia

My fish house is now completely empty, and all the fish are outdoors where they will stay until the first really cold weather. Then I will bring in the moors and veiltails; the Bristol shubunkins and fantails will stay outside all through the winter as they are very hardy.

After cleaning out the daphnia pond they have had a late bloom and I’m now feeding the fish with this excellent food, ideal for this time of year as they are easily digested and have good laxative qualities. So, with the addition of Wheat-Germ pellets, the fish are being well fed at this important time of year. Three sweeps of the pond produced the daphnia you see in this ice cream tub.


The annual cycle of goldfish keeping begins again…


Glass breeding tanks: 150 cm x 45 cm x 30 cm deep (60 x 18 x 12 inches deep); with a 25 cm depth of water these hold 180 litres (40 gallons).

Cull statistics showing how many of the original spawning are left after each cull of calico veiltails and moors:

Growing-on space: After the final cull, 340 square cm (55 square inches) of surface area are allowed for each of the young Bristol shubunkins (five to a tank), and 135–170 square cm (22–27 square inches) for each of the young twintails (ten to a tank).


[Back]    [Top]
© Bristol Aquarists' Society