All about white spot and it's treatment

[AndyGordon]

Introduction
There are two conditions referred to as white spot and a third - far more deadly  - condition, which looks very similar and is often mistaken for white spot. The two conditions which are actually white spot are Ichthyophthirius multifiliis (which lives in fresh water) and Cryptocaryon irritans (which lives in salt water). The third condition where the initial symptoms appear like white spot and which is impossible to tell apart just by looking is called Tetrahymena pyriformis: all three conditions have to be treated in a different way. This article will concentrate on the fresh water side of things only.

Ichthyophthirius multifiliis - Fresh water white spot
This is a fresh water only parasitic protozoa. It has quite a complicated life cycle involving many stages and it can apparently appear from nowhere under certain conditions.
The life cycle of fresh water white spot is as follows:

Theronts - the free swimming stage.
This is the only part of the life cycle where the parasite is vulnerable to medication. Theronts must find a host within a set time (temperature dependant) or they will die;

Trophont - parasitic stage.
This is the stage where the parasites can be seen on the fish: medication is ineffective at this stage;

Tomont - cell division stage.
When the cyst falls from the fish it sinks to the bottom of the tank where the cells divide within the cyst. Eventually up to 2,000 new Theronts emerge from each cyst to look for a new host. In the confines of a fish tank new hosts are easy to find and so the infection gradually worsens until the fish weakens so much that it could die if untreated.

Medication sold for this condition will only affect the theront stage of the life cycle so it might look initially as though the treatment is being ineffective.
There are a lot of myths about this disease and how it appears and then spreads. White spot often appears from nowhere when the fish are stressed. What actually happens is that the parasite can live in the background in the form of a low grade infection which goes unnoticed and has little or no effect on healthy fish. But, when the fish become stressed - as for example happens under new tank syndrome conditions - the fishes' immunity is compromised and the background infection is allowed to establish and multiply into a full-scale infection. This only needs to affect a single fish which then acts as a host and allows the number of theronts to increase dramatically and overwhelm the defences of even the healthiest of fish. If there is no low grade infection present to begin with then this scenario will not happen, however stressed the fish are.

Introducing a fish with white spot will also cause an outbreak in a similar way where it will act as a host and again, the increase in theronts will overwhelm the other previously healthy fish.

Treatment
There are a few options available and each is suited to different circumstances.

Medication:
The best option in most cases is to use a white spot medication, a good brand will not affect the nitrifying bacteria, is perfectly safe for the vast majority of fish and is extremely effective. There is no need to stress the fish with a rise in temp when using a chemical remedy in a tropical tank. Medications like this work very effectively at normal tropical temperatures: trying to make it work 10% faster at the expense of stressing the fish simply isn't worth doing; Don't forget to remove carbon or other similar chemical filtration media from the filter during treatment.

Temperature:
Some fish don't tolerate medication and are as likely to die through its use as they are from the effects of the disease. In this case there is another treatment which is quite effective (but not 100% effective) against all strains of white spot. It is also quite stressful to some fish. This treatment involves raising the temperature to OVER 30C i.e 32C and this needs to be done accurately because if the real temp is only 29.8C then the white spot will worsen dramatically.
Once the temperature hits 30C most strains of white spot parasites cannot multiply and so the disease slowly dies out. Once the fish have been clear of all white spot for a few days this treatment can be stopped.

It is important that this method is used properly to make it fully effective. Most of us know that we shouldn't make sudden changes to our fishes' environment and so the common sense approach would be to slowly raise the temperature until the desired level is reached - WRONG.
If you do this the parasite will increase dramatically as the temp starts to rise and a mild infection will turn into a very dense and life threatening infection. The temp must be raised quickly, as quickly as the heater will raise it in fact. Doing this will prevent a rapid increase in theront numbers and once the desired temp is reached they will begin to decline in number.

Very warm water holds less free oxygen than cooler water, so make sure that adequate aeration is added to the tank when using this method. I have also heard that adding salt when using this method will be helpful.
Well yes and no, salt is certainly effective against the parasite but it will also further reduce the level of free oxygen in the water and could put us in the situation where the treatment works but the patient dies!!!

Once the fish are free of white spot and have been free of it for a few days you can return the temp to a more normal level. BUT, unlike raising it the temp drop must be done slowly. If the fish have acclimatised to a high temp their metabolism will have speeded up, if this is suddenly reduced their metabolism will slow down and they may go on hunger strike as a result. By reducing the temp slowly their bodies will have time to adjust and problems can be avoided.

Cold water fish:
Are a problem since neither of the methods mentioned so far are really suitable. Chemical treatments break down and become ineffective after a relatively short time in water but the white spot parasite has a long life cycle in cooler conditions which in winter in a pond could last for weeks, making medication fairly ineffective. The temperature method can't be used because it would be too stressful for the majority of cold water fish to be kept at the temp required, and some would die as a result of the temp alone. Fortunately salt is effective against the parasite and it won't degrade in the water over time.

To treat with salt use a dosage of 3gms/l and remember to use the same level of salt with any water replaced during water changes.

Special thanks to Michelle (Tigerlily) for her fantastic help with this article.

Part two coming soon.

[TropicalFishForums]

[Nimbus]

Nicely said, Andy.  I detest whitespot with a vengeance and the more info we have about it, the better!

[freduk121]

Hi Andy,
Great article, look forward to next part.

A couple of questions re treatment or prevention.
Does the use of UV go towards the prevention of the disease.?
Many members advise the use of Garlic in conjunction with the heat treatment., your opinion.

Re cold water treatment, Many of my friends keep cold water fish, You haven't mentioned the type of salt required.

Regards
Fred.

[Lemmo134]

I had a problem with whitespot a couple of weeks ago and following some advice on here upped the temperature to 30 and added some garlic.
 
This cured the whitespot, which was apparent on my rams and rummy nose tetras, but unfortunately I lost 2 silver and 1 marble hatchet which were previously healthy and which I put down to the high temperature.

[AndyGordon]

Hi Andy,
Great article, look forward to next part.

A couple of questions re treatment or prevention.
Does the use of UV go towards the prevention of the disease.?
Many members advise the use of Garlic in conjunction with the heat treatment., your opinion.

Re cold water treatment, Many of my friends keep cold water fish, You haven't mentioned the type of salt required.

Regards
Fred.

Thanks Fred,

A UV will certainly help with white spot provided that it is a proper aquarium model and not a converted pond model because the two are very different and made to deal with different problems. An aquarium UV with a tube less than 6 months old and with the correct flow and rated for the volume of the tank will in all likelyhood prevent white spot completely.

For me the jury is still out on Garlic. It does have some benefits in that it stimulates appetite because it mimics the effects of insulin in fish and make them feel as though they need to eat, ill fish do go off their food sometimes so in that regard it will help but I do feel it is something of a fad too and it's effects do get exaggerated but I doubt it will do much harm in small doses so on balance my view is it may be of a small benefit but don't rely on it to heavily.

[skywatcher]

I can't  recommend esha exit strongly enough. Small bottle for less than a fiver. Medicated for a week and all gone but only a tiny amount used in the bottle.

Only thing id add is the company recommend treating for 3 days but due to the life cycle most recommend at least a week post last white spot gone.

[AndyGordon]

It depends on the ingredients, some are more stable than others. If it remains active in the aquarium for long enough then that dosage is fine. The fact that it works shows beyond doubt that this is the case.

[jimlard]

Thanks for posting this info, very interesting and very helpful as my fish have an infestation of white spot at the moment (although only between 1 and 10 spots per fish, not smothered like the photo in the first post.) I'm hoping I caught it early.

[sandy10]

Thank you Andy for the information in this thread - today found that our Red Phantom Tetras have the dreaded white spot.  Have treated our tank with Esha Exit and Esha 2000 and have given them some crushed garlic, was going to put the temperature up to 30 c but have left it at the 24 c as not to cause them too much stress.  There are not many spots on the fish just  hoping we have caught it early and don't have any fatalities!

Sandy

[ladyl78]

Hi!

I am new on here and was just about to post a question about whitespot when I came across your article!

We have a 60 litre tank which currently has 6 neon's, 2 x male guppys, 3 x female guppys, 2 x sunset platys (1 male and 1 female) and 1 x female wag platy.

Yesterday we noticed our sunset platys had small white spots on their tails. One of sunset platys unfortunately died yesterday, but we have 2 left. I'm really mad at myself, as I noticed the sunset platys were staying at the top of the tank on Saturday and acting a bit listless (this was before the spots came out).

I bought some King British White Spot treatment, removed the carbon pad from the filter and added the appropriate dosage last night.

I have a few questions:

1) Should I remove the affected fish from the tank? The rest seem very healthy and show no signs of infection so far

2) The platys are much more active today but the spots seems to have got worse?

I've to add the next treatment in tomorrow night. I'm worried I'm going to loose all my fish!!

Any help or further advice would be much appreciated.

Kind regards
Leona

[AndyGordon]

It is unusual for white spot to kill fish while others in the tank are unaffected. How long has the tank been set up for and was it cycled before adding any fish?
Have you tested the water for ammonia or nitrite, if so what are the results? Are there any other symptoms such has ragged fins/tail?

Sorry for all the questions but it will give us a better idea about the illness.

[ladyl78]

Hi!

Thanks for the reply. The tank has been running for a few years but has been empty (apart from our algae eater) for the last few months. The water and filters have been running and been maintained.

I have noted that one of my female guppies has a raggedy tail compared to the other 2, who have more 'perfect' colourful tails.

I have tried to add a pic but the file is exceeding the maximum size allowed even when zipped.

Leona

[ladyl78]

We have just removed the male platy from the tank as he was really sluggish and being pulled to the filter then going nuts and swimming around the tank in a frenzy??

[ladyl78]

Hopefully compressed pics now!!

[AndyGordon]

Can't really see much in the photos but from your description I would recommend getting the water tested asap, the white spot sounds like it is just a secondary infection and not the cause of the death. Treat the tank with protozin and don't raise the temp. Then please get the water tested for further advice.