Guppy's at surface and dieing

[Siny]

I've just introduced some new guppies to my tank (18 in total).
However since adding them 2 days ago, they are staying at the top of the tank (surface area) and 2 have already sadly died.

I have tested the water quality for nitrates, nitrites, ammonia, pH with my aph test kit and the water is showing healthy.
Inside the tank I also have a handful of tiger barbs, neon tetra's and a ruby shark. These fish were in the tank before adding the guppies and are having no problems at all. Happily swimming about doing their thing!

I initially thought maybe it was an oxygen problem despite having a healthy selection of plants, so I have increased the power from the air stone and also completed a 50% water change. Nothing has changed.

I haven't had guppies for about 2 years, am I forgetting something that is specific to them?

 

[seangee]

Shop bought guppies can be quite weak (genetically) and will be stressed after the move so it could just be "normal".

However tiger barbs are agressive and known fin nippers, so the temptation may be too much for them. The ruby shark is also territorial and aggressive so this tank is never going to be a peaceful community tank with its current inhabitants, and the guppies will be the most likely victims.

On a separate note your location is London. If you mean London, England you have very hard water. This water is ideal for guppies but the other fish you list all need soft water. Just mentioning this for awareness. These fish won't suddenly die overnight, but their life expectancy will be shorter than average and their colours won't be nearly as bright as in the wild. They will also most likely experience health issues as they get older.

 

[CryptFan]

Tank size?
tank stocking?
real parameters?

 

[Siny]

Thanks for the reply,

The tank is 150 litres. 1 Ruby shark, 3 tiger barbs and 6 neons. So plenty of space...
The shark has his own large log which he calls his home and is territorial over, but seems to only come out for a couple of hours a day max.

The reason I went for the large number of guppies was to make sure the shoal was big enough to help avoid tiger barbs (I read this in a magazine).

Hopefully they may eventually take to the tank if it is just the case that they are weak from the shop? If not i'm fearful that they may all die

Edit:
My APH test kit shows water as:
Ammonia: 0-0.25 ppm
Nitrite: 0 ppm
Nitrate: 0ppm
pH: Around 7.6

 

[CryptFan]

Parameters?

 

[Siny]

Just edited post to include:
My APH test kit shows water as:
Ammonia: 0-0.25 ppm
Nitrite: 0 ppm
Nitrate: 0ppm
pH: Around 7.6

 

[CryptFan]

With first generation shop guppies they are weak so any ammonia can kill them and cause sever stress

 

[Colin_T]

pictures and videos?

You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 2 heaped tablespoon per 20 litres of water.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 4 heaped tablespoons per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

 

[Essjay]

The reason I went for the large number of guppies was to make sure the shoal was big enough to help avoid tiger barbs (I read this in a magazine).

The usual advice is to have big shoal of tiger barbs so they keep their aggression between themselves, not to have large groups of other species. And even with a big shoal of barbs it doesn't necessarily mean they'll ignore the other species in the tank.
3 tiger barbs is, unfortunately, going to cause trouble. They need to be kept in a group of at least 10, preferably more.

The shark may also cause problems later as well. As they grow older they become territorial and aggressive. Keep an eye on it.

 

[Byron]

Agree with essjay. From the info provided in this thread, I would suspect the cause of the guppy deaths is either a problem with the guppies themselves, or aggression from the other fish primarily the Tiger Barbs and possibly the Ruby Shark.

A word on "aggression." This does not have to be physical, i.e., fish chasing/nipping/biting another fish. It can be chemical signals released by the aggressor (Tiger Barbs and the Shark are both aggressor fish) and read by the other fish. The stress caused by either form of aggression is serious.

You need to do something about the Tiger Barbs especially. Either get another six or seven minimum to have a group of at least 9-10, or re-home the three you have. If you do keep them and get more, there really will be no space for anything else. And I would worry about the neons in time, as the TB are likely going to challenge them if they have not already been doing this.