Goldfish varieties to keep in your biorb I

This is the start of a series of blogs on goldfish varieties to keep in your biorb.

This week it's what goldfish varieties NOT to put in your biorb... :)

In general it's best to keep to the fancy goldfishes with good constitution or good hardiness. Also, regardless of how hardy, the fast swimming goldfish such as common goldfishes and the sarasa comets are better kept outside in ponds where they have a lot of room to grow and swim around. They can grow to over a foot long in a pond and are most likely to rapidly outgrow a biorb's limited space very quickly.

A common goldfish with Red colouration


A Sarasa Comet

Plus the biorb has too small a space for these fast swimming fish to move in. It would be cruel to keep them in there.

Other fishes which are not advised are obviously the expensive and rare goldfishes. Especially the tosakins, jikins, even the ranchus... and of course the bubble-eyes due to the tube that Biorbs have sticking up in the middle.

A Tosakin - best viewed from above - has a lovely joined-up tail, and some difficulty swimming and breeding

A Jikin - also known as a peacock tail

A Bubble-eye goldfish - this photo courtesy of Bristol Aquarists

An extremely cute ranchu - this photo also courtesy of Bristol Aquarists
Technically small ranchus could be kept in the biorb, but since it has a head growth the water must be kept clean otherwise there's a risk of bacterial infection.

What to do if your biorb goldfish start breeding

If you've been diligent in controlling your water quality, and lucky enough to have a male/female pair in your biorb it's inevitable that they will start feeling randy and breed.

All the more so if you situate your biorb so that it gets some morning sun - mine is about 20 feet away from the window so it's very filtered sunlight - not enough to heat up the water or affect water temperature in any way.

Goldfishes tend to breed sometime in spring, though mine got confused once when I turned on the heating late in winter. The temperature in the house must have got quite low in autumn then when the heating went on they thought it was spring and started breeding in the middle of winter :S Even worse they kept on laying eggs throughout most of that winter - every few weeks, and I had no way of stopping them short of getting another tank and separating them. Since the whole point of keeping them in the biorb in the first place was that I had no space, that was not really an option.

There is no way you can keep fry in your biorb, for one thing too many of them will pollute the water. The other thing is that you will need to separate them from the adult fishes who love cannibalising their own eggs and fry. If you are not interested in rearing the fry then the best thing is to leave the eggs in your biorb and the adult fishes will eat them up for you. Make sure to perform a partial water change as soon as the breeding is over otherwise the poor fish will have to swim in milt (fish sperm) contaminated water.

If you do want to try your hand at rearing your fry then you will need to take out some eggs - not an easy manouver. Luckily if you have some Elodea (or other plants) plants in the biorb all you have to do is take those plants out. The eggs will be attached to the plants. Then put them in a 2 foot tank - oh dear - yes you will now have to buy a tank. With lights and a sponge filter.

Keep the fry tank lights on 24 hours. About 3-5 days after being laid the eggs will hatch and you will see some fry attaching themselves to the sides of the tank and the plants. There's no need to feed them at this stage since they are still living off their egg sacs.

48 hours after hatching, they fry will start swimming around and then you will need to feed them. Interpet do a good Liquifry and you can feed them with that 4-5 times a day. You can also make your own fry food - infusoria in particular grow when you put some banana in warm water and leave for some days in the sun. Alternatively just hatched brine shrimp are also good. You then use a pipette to give a few drops of that mixture to your fry. I make do with Liquifry being lazy.

After about 3 weeks, you can graduate on to the powder foods, Interpet also have powdered foods for fry. All the while you must do weekly partial water changes, and clean your sponge filter in non-chlorinated water. Keep a close eye on water quality - fry are very sensitive. A good way of changing water with fry is to:
(1) use a glass, dip it into your tank take it out then check if there's fry in there before discarding the water
(2) use some airline tubing to siphon the water off slowly

I prefer (2).

Make sure you cull your fry as you go along - remove those with kinks, are not swimming properly or just don't look like the ones you want to keep. With a 2 foot tank, you should be left with about 20 fry at the end of 8 weeks. Keep on culling as they grow - you could also sell those you don't want to keep or give them to your friends. Otherwise without culling you will lose all the fry due to poor water quality.

After that if you're keeping any of the fry it's time to put aside your biorb and maintain a bigger tank. If you're selling or giving away your new little goldfishes then you may be able to keep your original goldfish in your biorb for just a bit longer.

Keeping them in a 2-foot tank is the best chance you have of rearing fry. Since I have no space I use a goldfish bowl and do rather more drastic culling, and more frequent water changes. Usually end up with about 4-5 little fishes (from a batch of most likely 200 saved eggs!) which I then give away.

Ceramic media in your biorb

The ceramic media in your biorb performs the very important task of bio-filtration. No biorb should be without ceramic media. Do not - on any account - be tempted to use gravel in place of it. Usage of gravel risks scratching your biorb sides, and gets into your filter area, making difficult to remove and replace. I made the mistake of putting a combination of gravel and ceramic media in mine and have been regretting it ever since. The gravel bits just keep on getting stuck in the filter catches so that when I turn my filter to remove it it sometimes doesn't move past a certain point. Short of taking my goldfish out completely and up-turning the biorb to remove it I'm not sure what I could do. I've been patiently removing the little gravel stones by hand but they always manage to get back in.

Worst of all gravel is not as good a home as the ceramic media for your ammonia- and nitrite-removing bacteria. Both are absolutely critical when even attempting to keep your goldfish is such a limited environment as the biorb. Without these bacteria there is practically no chance of your goldfish surviving for long unless you are dedicated enough to perform daily water changes. This is because not only does gravel not have as much surface area as the ceramic media, it's more likely to be packed together resulting in less oxygen being available to the bacteria living on the gravel surfaces.

Once your bacteria is established, do not ever let your biorb touch chlorine or clean the ceramic media. Use of a siphon to suck up waste during water changes is fine, but no more.

Let's have a look at the chemistry of bio-filtration and the nitrogen cycle in your biorb.

The process goes as follows:

Plant - is eaten by - Fish - produces waste - Ammonia NH3 / Ammonium NH4 - is converted by bacteria into - Nitrite NO2 - is converted by bacteria into - Nitrate NO3 - is used by plants for growth

And there we are back to plants again.

Fish food introduced into the biorb will of course get ingested by fish and result in poo, the rest of the cycle remains the same.

These nitrifying bacteria are affected by oxygen, pH and warmth in particular. Nitrifying bacteria require a lot of oxygen so it is absolutely important that you make sure your pump is pumping air into your biorb. Your filter stone may get calcified (blocked up by calcium deposits) and that's when it needs changing. Otherwise not only will your fish be gasping for air, your bacteria will start dying off and will take a long time to re-establish.

That's why a bio-wheel (unfortunately not part of the biorb) is such a good filter - since it brings the bacteria up in contact with the oxygen available in the air.

Optimum nitrification occurs at about a pH of 7.2 to 8-3, then falls at higher values. Below 7.2, the nitrification rates drop to 50% at pH 7 (!!) and 30% at pH 6.5.

Temperature-wise nitrification rates increase as temperature increases. This needs to be considered with the fact that oxygen content in water decreases when temperature increases, so may prove a limiting factor.

In fact a little known fact is that aquarium plants tend to prefer ammonium and ammonia for growth, instead of nitrate, and will only use nitrate when there is no more ammonium and ammonia left. So having plants in your aquarium may help some with any ammonia spikes in your biorb. Even better it gives your fish something to munch on and adds fibre to their diet, hence reducing incidences of constipation.

Diagnosing goldfish health through Poo

Your goldfish's bowel habits can often be the first indication of problems. Diagnosed correctly and with remedial action quickly taken, more serious problems in future can be prevented.

Short to medium length poo: Healthy poo is the same colour as the food that the fish have eaten. The poo should be of short to medium length and should not be trailing your fish for long periods.

Long and thick poo: The poo is long and the same colour as the food the fish have eaten but it makes long trails behind the fish. This fish has been fed too much and is somewhat constipated. Feed peas only for 1-3 days.

No poo for sometime: If the fish has not been pooing for a day or more then it is constipated. Fish should be not fed for 2-3 days and then fed only peas for 1-3 days. A partial water change will reduce nitrate levels and that sometimes also helps with constipation.

Long and thin poo: Poo that is the same colour as what the fish has been eating but is thin and long, is usually caused by stress and the fish not eating well. Monitor fish closely, try to ascertain cause of stress if any, and remove it. If the problem is poor water quality, perform a partial water change.

Colourless whitish poo with air bubbles: The poo has air trapped in it and has no colour. This is a sign of constipation, the fish is not digesting its food properly. Fish should be not fed for 2-3 days and then fed only peas for 1-3 days.

Long and clear poo with many air bubbles: The poo has no colour but it is long and looks like it has air bubbles. If the fish is female, this is usually the fish re-absorbing eggs, otherwise it's trapped air and constipation.

Thin and whitish poo: The poo is whitish in colour. This may be a sign of a bacterial infection inside the fish. Monitor closely and if it persists, fish should be given only antibiotic food. In the meantime perform a partial water change. Prevention is better than cure so make sure your goldfish's diet includes spirulina algae.

What to feed your goldfish

Goldfish have a mainly vegetarian diet in nature - typically plants and algae, with the occasional insects. They do not eat much animal protein. So when you buy food for your goldfish make sure that the primary ingredient is of vegetarian origin and not animal protein such as shrimp or fish meal.

Do not feed goldfish on a diet of high animal protein - this causes them to become constipated. When constipated they may float upside down, float with their tail up, or generally lose their equilibium swimming in an unbalanced manner. If your goldfish are constipated, stop feeding for a day or two (if serious then 3 days), then feed only peas for the next 2-3 days. Peas are something of a laxative for goldfish.

I feed staples Tetrafin Gold Japan sinking pellets in the evening, and Nutrafin Max Spirulina Algae tablets for Tropical freshwater fish in the morning which has the added benefit of being able to be stuck on the side of the Biorb so the goldfishies can easily find it. I occasionally supplement with frozen green peas, 1 per fish, microwaved in some water for 10-15 seconds, allowed to cool then shelled and broken into fish-bite sized pieces. Finally I always keep Elodea in my Biorb for my fishies to munch on for extra roughage, and the nitrates in my Biorb result in good conditions for algae with my 8-10 hour light settings. Algae and Elodea plant growth also keeps nitrate levels down. Not that there's that much algae around with the fish constantly grazing on them.

It is good practice to soak the Tetrafin pellets for 2 mins before giving to the fish, otherwise the food may get compacted in the fish intestine and cause constipation.

I've heard these are also good but unfortunately not available in the UK: Progold. Though Fish Sempai do sell and ship in large quantities to UK. Aquadine do a good Duraflake Spirulina flake.

This is what Aquadine's website say about Spirulina:
"It will improve the intestinal flora of your fish thereby making them more resistant to bacterial infection. It has natural pigments (Carotenoids, Chlorophyll and Phuycocyanin) to make sure that all the colors of your fish stay bright and vibrant. Spirulina also stimulates production of enzymes that transport fats within the body. This allows your fish to convert fat into PFV (physiological fuel value) or growth rather than flab. The appearance of both fins and skin will often improve with the introduction of Spirulina Duraflakes, and it often enhances successful breeding."

Flakes also need to be soaked before being given to goldfish, otherwise since they initially float on the surface the fish will swallow air when eating them and cause air to be trapped in their tummies, resulting in bloatedness and equilibrium problems.

My goldfish also like the occasional frozen sweetcorn - prepared in the same way as the peas.

I haven't yet tried these but blanched spinach, insect larvae, chopped earthworms, nori seaweed and bits of hard-boiled eggs are also apparently good supplemental treats.

Feed only once or maximum twice a day, each time about as much volume of food as the size of their eyes, which is the size of their stomach, or as much as your fish can eat in 2 mins.

The main thing is to not overfeed. Sometimes you can let them go without food for a day once a week, and if you are away on holiday for a weekend or a week, it's best to just not give them any food rather than risk the water getting dirty. This is when the Elodea and the resident-growing algae come in handy for the fish to feed on.

Biorbs are bad for goldfish II

First, if you are keeping goldfish in your Biorb, only keep goldfish in there. If you have central heating you don't need a heater in your Biorb. Goldfish are happy in cold water between 15-20 C. If your house does go below that then put a Biorb heater in there, but set the temperature to come on at 16 C.

Before you buy your fish you should set up your Biorb and let it run for a couple of days. Make sure all the chlorine is gone. Then buy only 1 fish first. Add some StressZyme (or other bacteria liquid) after you've added the fish. Change water if needed - see what your water condition is like, if getting poorer then more often up to daily - usually with 1 fish should be fine. This is so the bacteria can start growing. Wait 1 week do a partial water change, then add another fish. Monitor water, partial change if needed then add another fish after a week.

I think 3 is enough - they will grow faster with more space, and you'll be happier too if your fish are healthy. :) You might be able to fit 5 in there if they are small and you have a 60L but they won't be small for much longer. If you have more fish you will have to change water more often, and you will have to move to a larger aquarium more quickly as they grow larger. When mine were just 1.5inches each I only had to change once a week. Now that they've grown to 2.5inches sometimes I have to change twice a week. When they get to 3inches I will have to change to the 60L or a proper aquarium otherwise the daily water changes will be too much for me. Luckily fancy goldfish usually grow only to about 4 inches not counting tails. Goldfish can live for over 40 years! So 3 is a good start, see how you get on with that.

With the celestial bubble eye, they will have trouble feeding if you keep them with fish other than telescope eyes and moors. Other goldfish will have much better eyesight so will eat all the food and you'll find your bubble eye starving away to nothing your eyes. If you have other fancy goldfish, oranda, ranchu etc you can't keep the bubble-eye. The moor and telescope eyes are ok - but you will need to use the ramekin/plate trick otherwise your telescope eye will also starve (due to its eyesight being poorer) if kept with other fancy goldfish like ranchus and orandas.

Another thing with the celestial bubble eyes is that Biorb has this tube sticking out with edges. They might break their bubbles on that, so you will have to make sure the edges are protected, and there are no other sharp things in there. Bubble eyes are not a good choice if you are a beginner with goldfishes. Orandas, telescope eyes/moors are much better.

Also, don't keep fancy goldfish with the other goldfishes like sarasa comets that can live in the pond outside. The sarasas are much faster and will eat all the food. Starting to see a pattern here.... :) And they might think your fancies are pregnant (due to the round tummies) and chase them.

Finally only feed them once or max twice a day. And only as much food volume per goldfish as their eye size (normal eyes not telescope eyes). They might eat from your hand if you train them, and that will also be a good way of making sure they all get to eat something.

Biorbs are bad for goldfish I

Truly it is not good to keep goldfish in a Biorb in the long term, and if you have a Biorb it's much better to keep tetras, siamese fighting fish or bettas, i.e. low waste producing fish. The goldfish really produce a lot of waste so you need to be diligent with your weekly water changes. But those other fish just not as personable as goldfish, so I figure then they'll get boring then I'll lose interest and change water less often, then they'll die anyway. My water changes take me only 10 minutes a week though, hence so far it's manageable.

The other thing is to not overfeed. Sometimes you can let them go without food for a day once a week, and if you are away on holiday for a weekend or a week, it's best to just not feed them rather than the water getting dirty.

And get a siphon with wide opening at the sucking end so you can agitate the ceramic media to get rid of any waste in there, and a suction valve at the outlet end so it's easy to just squeeze to start off the siphon. Put your plants in little terracotta pots so they don't float up when you agitate the ceramic media.

Make it as easy as possible to change water then you'll do it more often. Do make sure the water is a same temperature, or if not then slightly cooler fresh water is much better than slightly warmer. Too warm an increase with the new water and they can just die almost immediately.


And the plants once the goldfish eat them, you just replace them with new ones. The Elodea is best since as well as being quite tasty, it also grows quite fast. Make sure when you put in new ones there are no parasites on them - so rinse and immerse for a week in chlorinated water in sunlight if possible to kill off as much of the parasites you can, then dechlorinate and put in with your fish.

The goldfish will eventually get bigger so you will definitely have to rehouse them in future. But it does take them 2-3 years to get bigger so provided you stick to 3 (or 2 if you prefer) you'll be able to enjoy your Biorb for a couple of years, then after you rehouse to a bigger tank in future you can still keep it as a isolation tank for new fish, or when your fish are breeding, your fry. One goldfish is a bit boring for the goldfish and you, then the other danger is that you lose interest and stop changing water.... and the poor fish might die anyway. 2 is also good and will be less work water-wise, I like 3 (whether 30L or 60L Biorb) though because if you're lucky enough to get 1 female and 2 males (also the best combination for good fry), the males start doing little circular chases with each other during breeding time when they try to breed with the female, then they'll both chase after the female.