As you know I cycled my tank using ammonia it was cycled for about 10 days before I added any fish during which time I continued to add ammonia. On Saturday night I did an almost 100% (apart from the water in the gravel) water change.

On Sunday morning readings were

Ammonia 0
Nitrite 0
Nitrate 10-20

On Sunday I got 9 male guppies (I asked for 8 but when I got home there was 9 in the bag) from a reputable aquatic store.

I acclimatised them to the tank gradually and did not feed them on Sunday.

Water readings yesterday:

Ammonia 0
Nitrite 0
Nitrate 10-20

This morning I have found a dead guppy up against the filter. I can't see any obvious signs of disease, the fish had lost it's colour though I assume that is normal in death.

All fish seemed fine last night.

I have a 96 litre Juwel Record with hard water.

Do you think the fish died from stress or should I be looking out for anything else. The other fish look fine (but so did this one).

I have some stress coat is it worth adding some?

Thanks

Oh Sorry, readings this morning

Ammonia 0
Nitrite 0
Nitrate 20

Thanks

Sorry to hear that.
The water parameters are fine :/
Could you answer a few questions?
How did you introduce the fish to the tank? Did you float the bag and slowly introduce the water? Did you let them come out on their own?
Do you know the pH at the retailers?
Guppies are fragile now, they used to be a hardy fish but that has been bred out of them after years of breeding for the trade.

One of the advisers will be along shortly.

Hi

I floated the bag for 20 mins the gradually added water to the bag every 10 mins then after 1 hour I took them out with a net as I read you shouldn't add the water from the bag to your tank.

Did I stress them out too much doing it this way?

Probably not due to transport stress. What are your pH and gH? What temperature is the tank at?

pH is 8.0
GH is 180 (I only have test strips for this as they had no liquid tests in my LFS)

Temp is 25.9

This evening one of the guppies keeps swimming on it's side for a bit then flips the right way and goes back on it's side again.

Is there anything I should be doing?

I think you've just been a victim of poor stock to be honest. All your water reaings are fine, as is the temperature.

It's unfortunate, but a lot of the Guppy stock in the shops these days is weak and this happens all too often. There's been far too much inbreeding and the Far Eastern farms that supply a lot of wholesalers basically have the fish swimming in antibiotics due to their poor immunity. Just continue to provide good food and clean water and hopefully soem will be OK

Okay thanks Fishlady, that is reassuring. Is the GH okay? I thought it may be a little high but I don't really rate those test strips, I will get a liquid kit.

I will keep a close eye on them and change the water towards the end of the week or sooner if nitrates rise.

I am using the Tetra Colour pro food and I also have some frozen bloodworm and Daphnia though I have not given this yet so far I have just fed a few flakes of food in the evening.

gH is OK. Guppies gH range goes from 10 to 30 degrees. 180 ppm is equivalent to just over 10 dgH so is at the bottom. However if that's a test strip result it may not be very accurate and if the hardnes is lower than that, it may be a factor in the problem.

Get liquid tests for everything as soon as you can, as for the other parameters too, the test strips are not very good. Did you use them to cycle? Only your cycle was very fast so am a little concerned that the readings you've been getting may not be correct.

In the meantime you can check your gH on your water supplier's web site.