What Filter

[Telstar]

I'm curious...did you read the responses to your initial question?
Where did you get the idea of 'bacteria' from, or 'disease'?

We know, without any doubt, that an uncycled tank will poison your fish, especially a smaller tank such as a 25l one.
Hopefully, once you've read the cycling info provided, you'll be able to start again, slowly and carefully and eventually get to enjoy the hobby as we do.

.. yes thanks read all replies. Discease was only remaining choice. The tank ws set up fresh; water, pump filter ok. Had a shrimp swimming in it for days before introducing 4 Gupies in a 25L tank with pump ect all running well. When the Gupies were introduced the shrimp (a large happy beast) died next day. Two Gumpies died day after. Had Gumpies replaced and two small shrimps, free from shop. Everybody then remained to the top of tank, the Gupies dived down now and again but srayed at top of tank. Shrimps actually out of tank! Gupies began to die. All we could think of was the water had been contaminated by first Gupies. If so damage done all we can do is start again which is not a big problem. We will introduce smaller fish bit at a time but having in mind they are shoal creatures. Thanks very much, responses all appreciated.

 

[Essjay]

The most likely reason for the deaths is ammonia poisoning.

Fish etc excrete ammonia as waste. Shrimps have little bioload so the shrimp which was the first occupant of the tank would make very little ammonia. Then you put guppies in the tank which would make a lot more ammonia than the shrimp. Because it's a brand new tank which was not cycled before any livestock were added, there was nothing to remove the ammonia so it built up, and in 25 litres it would build up fast. Ammonia is poisonous to fish and shrimps.
Shrimps climb out of a tank when there's something in the water they don't like.
Fish gasp at the surface when ammonia burns their gills.

 

[Telstar]

The most likely reason for the deaths is ammonia poisoning.

Fish etc excrete ammonia as waste. Shrimps have little bioload so the shrimp which was the first occupant of the tank would make very little ammonia. Then you put guppies in the tank which would make a lot more ammonia than the shrimp. Because it's a brand new tank which was not cycled before any livestock were added, there was nothing to remove the ammonia so it built up, and in 25 litres it would build up fast. Ammonia is poisonous to fish and shrimps.
Shrimps climb out of a tank when there's something in the water they don't like.
Fish gasp at the surface when ammonia burns their gills.

.... found the problem!!! .... although all appeared well, the air filter/pump has not been working, we've starved them of oxygen. SO STUPID. Fish that are left now swimming about happy as larry. We'll get a new filter anyhow.
The filter came with the tank inherited from an elderly lady. But yet the shrimp was alive n well on its own.
Anyhow it's working, we can move on and enjoy our tank with fish (alive). Thanks for evrything I'm sure there will be more as we go. No doubt next month my wife will want the wall taken down rebuilt with a massive tank - what have I done?

 

[Bruce Leyland-Jones]

.. yes thanks read all replies. Discease was only remaining choice. The tank ws set up fresh; water, pump filter ok. Had a shrimp swimming in it for days before introducing 4 Gupies in a 25L tank with pump ect all running well. When the Gupies were introduced the shrimp (a large happy beast) died next day. Two Gumpies died day after. Had Gumpies replaced and two small shrimps, free from shop. Everybody then remained to the top of tank, the Gupies dived down now and again but srayed at top of tank. Shrimps actually out of tank! Gupies began to die. All we could think of was the water had been contaminated by first Gupies. If so damage done all we can do is start again which is not a big problem. We will introduce smaller fish bit at a time but having in mind they are shoal creatures. Thanks very much, responses all appreciated.

No...you haven't absorbed ANY of the information regarding cycling and the symptoms you describe indicate ammonia poisoning. (Look up 'New Tank Syndrome' while you're at it).

.... found the problem!!! .... although all appeared well, the air filter/pump has not been working, we've starved them of oxygen. SO STUPID. Fish that are left now swimming about happy as larry. We'll get a new filter anyhow.

Given the number of fish and the available surface area of your tank, I doubt very much that a lack of aeration was the problem.
Essentially, you asked the question and didn't like the answers and have insisted on blaming something/someone else, rather than take some responsibility for your own lack of knowledge.