Fish Health

Are your fish off-colour? Are some behaving strangely? How do you treat fin rot, parasites or fungus?

Birds, Parasites and Koi Pond Health

Q: My pond has a waterfall which returns my filtered water back to the pond (2,300-gallons). As I sat in my garden enjoying my koi , I started to wonder if the wild birds are introducing pests into the pond. As they fly away after a . . . → Read More: Birds, Parasites and Koi Pond Health

Bloated koi. What can I do?

Growing large and voluminous koi is the objective of many koi keepers. Having purchased a beautiful specimen, the quest is to help the koi to grow to its full potential. These koi are provided with a high protein diet and an expansive pond to provide koi . . . → Read More: Bloated koi. What can I do?

Clays buffers in a Koi Pond.

When we view a pond full of koi, swimming and thriving in a high quality pond environment, we are in fact witnessing the product and embodiment of thousands of different microscopic processes that will never be seen by our naked eye. Every time a koi eats . . . → Read More: Clays buffers in a Koi Pond.

Dissolved oxygen and pond fish

Dissolved Oxygen Concentration (DOC) is the term given to describe the amount of oxygen that is dissolved in pond water.

Dissolved oxygen is measured in terms of how much oxygen (by weight – mg) is dissolved in every litre of water. There are many factors that will . . . → Read More: Dissolved oxygen and pond fish

First Aid for Pond Fish – What to do when things go wrong.

Despite our very best efforts, fish health alerts and emergencies can occur completely by surprise. Problems can arise through no apparent fault of our own or can equally be as a direct result of our action. Either way, if we do not act swiftly and decisively . . . → Read More: First Aid for Pond Fish – What to do when things go wrong.

Fish Garden Pond Water Treatments – How they work.

Koi keeping is becoming an increasingly complex hobby, driven by the needs and expectations of ourselves and our koi.

On the one hand, the needs of our koi have never changed, being the same today as they were at the turn of the last century, whereas our . . . → Read More: Fish Garden Pond Water Treatments – How they work.

Gasping pond fish

Pond problem solver – gasping fish

All pond fish breathe by pumping water over their gills to extract oxygen, which is dissolved in the pond water. Fortunately, compared to other fish species, the carp family do not require an especially high level of dissolved oxygen (DO) which . . . → Read More: Gasping pond fish

Goldfish health problems. Treating fish disease.

As any responsible, loving parent will testify, it doesn’t matter how well you look out for your children’s welfare, at some time they are likely to experience an unpredictable eventuality or catch the latest bug that is ‘going around’.

These health problems are recognised as the trials . . . → Read More: Goldfish health problems. Treating fish disease.

Koi dies suddenly

Not a very pleasant headline, but all the same a very realistic issue that in the experiences of a pond owner or koi keeper, will at some stage, probably become a reality.

The background to such a fatality may be along the lines of the following. The . . . → Read More: Koi dies suddenly

Koi or gold fish has ulcers

Unfortunately, the numbers of koi suffering from ulcers has increased over recent years. The majority of koi keepers will have experienced this problem and had mixed results in successfully treating koi with ulcers. In many respects, an ulcer represents a real challenge to a koi keeper . . . → Read More: Koi or gold fish has ulcers

Koi pond fish stress

Fishkeeping should be available on prescription from the NHS. Scientifically proven to cause a drop in blood pressure and reduce heart rate, watching fish should be recommended to anyone who feels they need some stress relief.

Be it lounging by a pool, lapping up the gentle movements . . . → Read More: Koi pond fish stress

Koi pond quarantine. Should I quarantine my fish?

Q: I have inherited a Koi pond and I now want to buy some Koi of my own. What procedures do I have to follow when introducing these new residents? Should I quarantine them first? What is the best way to do this? What sort of . . . → Read More: Koi pond quarantine. Should I quarantine my fish?

Koi pond water affected by pond medications

I found it difficult to follow and understand, could not see at the time why I needed it and having scraped through the exam promptly forgot most of it – ‘O’ Level Physics!

One law I do remember though (and thank you ‘Chopper’ Williams, for explaining it . . . → Read More: Koi pond water affected by pond medications

Koi Stress. How to reduce it.

Fishkeeping should be available on prescription from the NHS. Scientifically proven to cause a drop in blood pressure and reduce heart rate, watching fish should be recommended to anyone who feels they need some stress relief.

Be it lounging by a pool, lapping up the gentle movements . . . → Read More: Koi Stress. How to reduce it.

Koi treatments pond medications

Ever since Adam and Eve sinned in the Garden of Eden, man has been struggling with the problems of an imperfect world such as weeds, death and disease. This is very true for the koi keeper who over the years has been forced to experiment with . . . → Read More: Koi treatments pond medications

Koi ulcers

Unfortunately, the numbers of koi suffering from ulcers has increased over recent years. The majority of koi keepers will have experienced this problem and had mixed results in successfully treating koi with ulcers. In many respects, an ulcer represents a real challenge to a koi keeper . . . → Read More: Koi ulcers

My koi have stopped feeding

Koi keeping can put many unnatural pressures on koi that these artificially selected fish have not had to contend with in their wild ancestral form. Over thousands of years, their physiology has adapted to a sedentary, slow moving existence in the mid to deeper waters of . . . → Read More: My koi have stopped feeding

My koi keep flicking flashing?

Ooh, down a bit, down a bit, a little to the right, a little more, just a bit harder, yes that’s just the spot! Why is it that when we’ve got an ‘itch’ we just can’t reach it and no matter how well you direct someone . . . → Read More: My koi keep flicking flashing?

My koi keep flicking or scratching.

Ooh, down a bit, down a bit, a little to the right, a little more, just a bit harder, yes that’s just the spot! Why is it that when we’ve got an ‘itch’ we just can’t reach it and no matter how well you direct someone . . . → Read More: My koi keep flicking or scratching.

New Pond Syndrome can cause problems in a new garden pond

Dear Ben,

Could you please tell me what ‘new pond syndrome’ is all about? I have heard this term before but never really understood it, and I think it’s about time I did, since I am moving my koi to a new pond very soon. Does this . . . → Read More: New Pond Syndrome can cause problems in a new garden pond

Overdosed my pond by accident

Whether plagued with blanketweed or afflicted by disease, there will come a time when a pond will require medication to treat a problem.

Fortunately, the majority of common ailments such as whitespot, fin rot and ulcers can be treated and controlled by adding a recognised medication to . . . → Read More: Overdosed my pond by accident

Overstocking problems with koi or goldfish.

Each Christmas, with only a few days before Christmas Day, supermarkets are absolutely packed and so are our trolleys, full of choice items that will make the festive period a happy one.

Most of us are probably guilty of over-buying at this time, getting carried away, only . . . → Read More: Overstocking problems with koi or goldfish.

Pond fish koi are gasping?

Dissolved oxygen concentration             

Q: At various times this summer I have seen my Koi gasping at the pond surface and around my waterfall. Does this mean that there is not enough oxygen in the pond? Is this because of exceptionally high temperatures or for some other reason? . . . → Read More: Pond fish koi are gasping?

Pond fish koi medications. How do they work?

Ever since Adam and Eve sinned in the Garden of Eden, man has been struggling with the problems of an imperfect world such as weeds, death and disease. This is very true for the aquarist who over the years has been forced to experiment with different . . . → Read More: Pond fish koi medications. How do they work?

Pond fish koi treatments

Every garden pond, even the smallest contains a living ecosystem. We can fall into the trap of regarding the water in a pond as playing an insignificant part in maintaining our fish in tip-top health. This misconception is all the more evident when confronted with sick . . . → Read More: Pond fish koi treatments

Pond medications. How to use them safely.

Maintaining a healthy and stable pond environment is the single most effective method of ensuring fish stay in top condition. This is best achieved by filtering the pond, introducing fish gradually, feeding wisely and not over stocking. Fishkeeping perfection must be so easy!

Alas, if we had . . . → Read More: Pond medications. How to use them safely.

Pond pH keeps changing

Koi benefit significantly from stable water conditions, where water quality parameters such as temperature, dissolved oxygen, ammonia and nitrite should be maintained within desirable levels. This is especially true for pH which must be remain consistently between pH7 and pH9

pH is one of the most widely . . . → Read More: Pond pH keeps changing

Sudden koi death

Not a very pleasant headline, but all the same a very realistic issue that in the experiences of a pond owner or koi keeper, will at some stage, probably become a reality.

The background to such a fatality may be along the lines of the following. The . . . → Read More: Sudden koi death

Toxic materials around the pond. What is safe?

What chemicals can leach out of pond-side materials? What effects will they have on water quality and the Koi themselves? In what ways can you seal these materials? Can you use the same sealant for them all?

When considering the topic of leaching in and around koi . . . → Read More: Toxic materials around the pond. What is safe?

What has poisoned my koi?

Dear Ben

I have a great 2000 gallon pond and a mixture of koi and orfe in my pond. My filter system is quite a straight forward gravity fed filter, and I have three airstones plus a UV.

My pond is quite heavily shaded by tall trees, hence . . . → Read More: What has poisoned my koi?



Kill blanketweed and string algae.