A bit concerned about Larry my Weather Loach

I noticed yesterday some white spots on Larry my weather loach which im a little concerned about, he is definitely my favourite fish in my tank which consists of about 10 other very small fish like neon tetra's, guppies and 2 African black dwarf frogs, I dont think this is white spot as they dont seem small enough and non of the other fish are affected, could they be ulcers ? or are these wounds ? he is a bit crazy and loves to swim at speeds around the tank, he doesnt care who's in his way, ive seen him many times bumping into other fish and items in the tank, there is 1 or 2 on one side, and 3 on the other side of him.

A little story behind my tank, I had a 64 litre tank which I brough 2nd hand, it came with a Fluval U3 which I changed all the filters in, I used tap water to fill it up and was having a complete nightmare trying to get rid of nitrates and nitrites, in fact so bad I lost my rainbow shark a 4 neons to the water, I added various tetra products to bring the NO2 and NO3 down, but seemed to be fighting a loosing battle, in the end I gave up and brought a brand new 105 litre tank, I completely filled it with deionised water, ran tests on the water and everything was fine, after heating the water overnight, the water was crystal clear, the next morning I transferred to filter and fish etc to the new tank, the following morning to my horror, i discovered what basically looked like a cloud had parked in the tank overnight, ran tests again and they were all coming back within the ranges, I wasnt happy at all, I immediately took out the Fluval U3 and replaced it with a brand new Tetra EasyCrystal 600, ive come down this morning and the water is crystal clear again, I know fluval have some good reviews, but i'll never use one or buy one again.

probably excess mucous caused by poor water quality (ammonia, nitrite, nitrate), which in turn is caused by a new tank and filter. The white cloudy water is also caused by this.

If you need to reduce ammonia, nitrite or nitrate, do a 75% water change and gravel clean the substrate every day until the levels are 0ppm.
make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Too much food will also cause problems, especially in a new tank where the filter is still developing the beneficial bacteria. If the tank and filter are less than 6 months old, reduce feeding to once every couple of days.

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The first line of treatment for the loach would be a 75% water change and gravel clean every day for a week. See how it looks after that. if the problem gets worse, post more pictures and test the tank water for ammonia, nitrite, nitrate and pH, and tell us the results in numbers.

Colin_T said:

probably excess mucous caused by poor water quality (ammonia, nitrite, nitrate), which in turn is caused by a new tank and filter. The white cloudy water is also caused by this.

If you need to reduce ammonia, nitrite or nitrate, do a 75% water change and gravel clean the substrate every day until the levels are 0ppm.
make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Too much food will also cause problems, especially in a new tank where the filter is still developing the beneficial bacteria. If the tank and filter are less than 6 months old, reduce feeding to once every couple of days.

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The first line of treatment for the loach would be a 75% water change and gravel clean every day for a week. See how it looks after that. if the problem gets worse, post more pictures and test the tank water for ammonia, nitrite, nitrate and pH, and tell us the results in numbers.

Click to expand...

Thank you, as I said in my OP, the new tank I filled up completely with deionised water, so basically 100% water change, that was 2 days ago, the tests were coming back clear before I transferred the fish and filters etc over, the gravel was washed and cleaned before putting it in the new tank, the only old tank water to come to the new tank was during the transfer of the fish.

It sounds like the aquarium is not cycled

The old filter media from the original filter would likely have held some good bacteria needed to kickstart the new aquarium, same with the substrate too.

It takes an average of 7 to 9 weeks to cycle a new aquarium without fish in it and an average of 8 to 13 weeks to cycle an aquarium with fish in it.

The biggest issue with a fish in aquarium cycle is that the fish usually suffer the effects from the constantly differing water chemistry and they frequently die as a result. Cycling an aquarium with fish in there can be done but is by far the trickiest due to the fish having a low tolerance of the chemistry changes as an aquarium matures during the cycle process.

You should read the information on this thread to aquaint yourself with the processes involved, I feel you might need to prepare yourself to lose fish as that does happen sometimes when doing a fish in cycle process.