I may have cooked my son's guppies. One dead so far :(

We bought our 2 year old a tank back in February. He has 5 lovely male guppies and is really enjoying them.
The tank has bright led lights in the lid and we get a reasonable amount of algae; we've been told it's b cause if the lights and that a uv steriliser would help.
Today I bought what I thought was just the ticket and added a submersible uv light bulb to the tank. 4 hours later one fish is dead and the rest are looking strangely opaque and are twitching when they swim.
The light is now in the bin and the fish are twitching/swimming in darkness.
Is there any hope for them or will I be waking up to a load of floaters?
Any help/advice much appreciated.
Stressed Mammy.

I cannot offer much about the issue itself, except to remove what ever you added and return it. It is not necessary to have UV on freshwater tanks, and it wouldnot likely stop algae anyway. It can help green water but not algae growing on surfaces.

As for algae, unless you have plants, this is not usually detrimental. Algae is a plant in that it removes nutrients and produces oxygen. I obviously don't know the extent of the algae, it can be out of control, but it would be better to ID the algae, look at the complete picture (tank size, fish load (5 guppies), feeding (fish do not need very much every day so overfeeding can be a problem), and the light duration.

Byron.

Could you post a picture of the bulb or provide a web link to the product?

StevenF said:

Could you post a picture of the bulb or provide a web link to the product?

Click to expand...

Thank you.

This is the product: the instructions mentioned only using it for 10 mins online but the paperwork said 12 hours.
The fish have now all died. I think it's just been a poor investment on my part.

Byron said:

I cannot offer much about the issue itself, except to remove what ever you added and return it. It is not necessary to have UV on freshwater tanks, and it wouldnot likely stop algae anyway. It can help green water but not algae growing on surfaces.

As for algae, unless you have plants, this is not usually detrimental. Algae is a plant in that it removes nutrients and produces oxygen. I obviously don't know the extent of the algae, it can be out of control, but it would be better to ID the algae, look at the complete picture (tank size, fish load (5 guppies), feeding (fish do not need very much every day so overfeeding can be a problem), and the light duration.

Byron.

Click to expand...

Thank you so much.
I think the light is the issue. The multi coloured led lights can by on for around 12-15 hours per day. We've reduced this greatly.
Ive realised the instructions on the product were contradictory too with online saying 10 mins of use and the packaging saying 12 hours.
I've put it down to naivety and carelessness on my part and I've paid the price as all my son's fish are now dead.

I'll let Steven comment on the UV bulb as I have no experience with that. But it would seem to have been the problem.

Back to the algae...do you have live plants (aside from algae, lol) in this tank? If yes, then dealing with the algae is essential or it can kill the plants. If no, then getting things balanced with algae present is OK. Again, I don't know what type of algae, some is quite attractive, some anything but and also dangerous. A photo of the tank showing this algae would help here.

That bulb you purchased is designed to kill all living things in a storage container of water with no plants or fish. For example a water barrel or cistern attached to the gutter drain of a house. It was never designed for aquariums as the add states. Try and get your money back. Your fish have been injured by this product. They may or may not recover. And there is little you can do to help them.

This is what a typical in tank UV sterilizer looks like. Note in the picture you cannot see the bulb. All of the UV light is contained in the unit. and a small pump circulates water around the bulb. A foam scen or screen typically keeps fish and shrimp out. These are good a killing bacteria / algae/ and parasites that are free floating in the water. They will not address algae growing on plants.
https://www.google.com/aclk?sa=l&ai...hUKEwi2w4Gt0N7TAhXKylQKHZPkABEQpysIwgE&adurl=