White spot disease – more widespread than supposed

Almost every aquarium owner has experience of the white spot disease ( Ichthyophthirius multifiliis or "Ich" for short) on their fish. And this is the interesting point: Many of them successfully used a remedy against white spots, e.g. JBL Punktol Plus 125 while the remedy did not work for others. There are many facts which help explain this situation.

Let’s begin with the diagnosis: Unfortunately most aquarium owners don’t recognise the white spots until the fish begin to look like pastry crumble.

Single white spots often are overlooked. Unfortunately one single Ichthyophthirius parasite, which means one spot on the fish, can lead to 1000 new spots because this parasite goes through a life cycle, of which the white spot on the fish represents only one stage. By the way, this stage cannot really be combatted with remedies anyway, since the parasite has bored into the fish’s mucous membrane and therefore is “protected”. After a while the single-cell organism separates from the fish and falls to the bottom where it changes into a capsule stage which is equally resistant to remedies. After a short time the capsule opens and releases about 1000 new Ichthyophthirius parasites into the water, and these look for hosts so that they can transform back into visible white spots on the fish. But in this free stage (swarm out stage) the parasites can be combatted successfully with remedies. If, however, the disease is recognised too late and the fish is already carrying (let’s say) 10 spots, then 10 x 1000 swarming parasites will develop in the next reproduction! This high number means the risk of infection for the fish increases and they get more seriously and more quickly infected than they would have done with only one spot.

That’s why an early diagnosis is essential!

The life cycle with its different stages makes a single treatment with one remedy useless. You will only catch a few free parasites in their swarm out phase – and nothing more. Therefore JBL recommends reapplying the remedy every second day, 8 times in total. This alone will ensure that each spot has completed its life cycle and has reached the swarm out stage, where it can be killed.

Supplementary measures

As well as applying the remedy JBL Punktol Plus, further measurements are recommended:

1. A raise of the water temperature by about 3 °C, but not over 30 °C, can help to accelerate the life cycle of the Ichthyophthirius parasites to get them into the swarm out phase more quickly, in which the remedy can kill it off.

2. A strong partial water exchange of 50 % BEFORE the initial application reduces the number of the pathogens in the water by 50 % and thus reduces the risk of infection for the fish.

3. The addition of half a dose JBL Ektol cristal leads to a reduction of mucus on the fish as result of the salt concentration in the water. Thus the pathogens are emitted into the water and can be combatted.


Combatting the white spot disease (Ichthyophthirius multifiliis) will not be a problem if a few things are taken into account:

1. Act quickly and don’t wait until the fish have a lot of white spots.

2. A partial water change of 50 % BEFORE the first treatment reduces the risk of infection.

3. Use the remedy JBL Punktol Plus 125 every second day until the 15th day. Don’t stop if you can’t see any more spots: the pathogen is not always visible.

4. Raise the water temperature by 3 °C, to 30 °C max, to fight the pathogen more effectively.

5. The addition of half a dose JBL Ektol cristal helps to disengage the pathogen from the fish so that the pathogen can be defeated.

© 26.01.2016
Heiko Blessin
Heiko Blessin
JBL GmbH & Co. KG

Tauchen, Fotografie, Aquaristik, Haie, Motorrad