Fish dying when do a water change

[Andy Pierce]

I'm also inclined to blame overdosing the dechlorinator. Note the instructions: Use 1 capful (5 mL) for each 200 L (50 US gallons) of NEW water [emphasis mine]. Old tank syndrome is tempting to blame and may also be a factor, but unless you are dramatically disturbing substrate on water changes that would be a more gradual decline rather than a sudden killing upon a water change. I really doubt there is something inherently evil in your water supply. Certainly switching to the correct amount of Prime is easy to try. What else are you adding to the new water - is it only Prime and nothing else? Since you are only replacing 20% of the water on a water change as long as you have reasonably good water flow in the tank you can rule out 'shock' from either rapidly changing pH or temperature - the 20% new water won't really move the needle meaningfully on either of those.

 

[hypnogogia]

Seems clear to me there’s nothing to loose from cha hing the prime dosing, although as @John q points out, the deaths predate the use of prime.

 

[Bradders]

Agreed - the Prime aspect IS a problem, but it might not be THE problem.

 

[simon_the_plant_nerd]

You're likely not drinking from a hot water tank though, right? So you'd not necessarily notice.

I’m inclined to agree with this too. The concentration of contaminants in water would ordinarily need to be much higher to cause harm to humans than to aquatic life.

Perhaps bottled water is mainly drank in this household. Or, considering they are also in Scotland, they may be like me and have a healthy fridge full of Irn-bru?

 

[Hanuman]

Without being the practitioner of doom I'd say the prime suspect isn't prime, the op was loosing fish prior to adding it. See text from original post.

Why are the fish dying? I'm not sure. The standout clue for me is the disparity between tank ph 6, and tap water ph 8.2 average from the report. On a side note with such low conductivity 78 us/cm I find it odd that the tap water ph is so high.

Wish I could offer some constructive advice, I can't other than than suggesting you try a water change with added kh and see if that helps.

Actually the way the sentence is written it is unclear to me whether he has been using Prime all along. I assumed he would be using Prime everytime since he is using tap water. That's a question he needs to clarify. If he was not using prime and he was loosing fish, then definately the Prime use is not the issue.

 

[Myrkk]

You can’t live too far from me so if you would like to do a comparison of your water and mine, I’d be happy to help you out. I have a TDS meter and some various test kits which I wouldn’t necessarily rely on for quantitative measurements but will do for a comparison between the two waters, just to see if there is any difference.

Should give you an idea if there’s something leaching into the water from your pipe work.

Simon that is very kind and if you are happy to I’d be grateful. I can PM you where I live, or I can take some water and meet you halfway if that’s easier. I’m EH37

 

[Myrkk]

I used to use stress coat and switched to prime around 6mths prior to moving to where I live now.

 

[Myrkk]

I’m inclined to agree with this too. The concentration of contaminants in water would ordinarily need to be much higher to cause harm to humans than to aquatic life.

Perhaps bottled water is mainly drank in this household. Or, considering they are also in Scotland, they may be like me and have a healthy fridge full of Irn-bru?

Interestingly, I drink boiled tap water and I’ve said since we moved in to this house that it has a funky taste. We’d bought a new kettle though as the movers lost our old one and it took weeks to find it. That “funky” taste has never dissipated and I always thought it was the plastic on the kettle. Maybe it is the water after all.

As far as the other poster mentioning the discrepancy of pH, I have two hunks of wood in the tank and usually lots of leaf litter which I believe drop the pH?

 

[John q]

I used to use stress coat and switched to prime around 6mths prior to moving to where I live now.

So prior to moving you used prime for 6 months without issue?
It's confusing, lol. Can I suggest you change 10L of water add only 0.25ml (5 drops) of prime to the bucket that contains the water going in and gauge the reaction of the fish.

I think doing the above might help us start ruling things in or out.

 

[sparkyweasel]

That “funky” taste has never dissipated and I always thought it was the plastic on the kettle.

Have you tried boiling water in a saucepan and tasting that?

 

[Myrkk]

So prior to moving you used prime for 6 months without issue?
It's confusing, lol. Can I suggest you change 10L of water add only 0.25ml (5 drops) of prime to the bucket that contains the water going in and gauge the reaction of the fish.

I think doing the above might help us start ruling things in or out.

the fish are still a little stressed and panting, so I’m going to wait until they are stronger, then I’ll try this. I really do not want to lose any more.

I’m sorry it is so confusing. I will try and get the time to do a bullet point list which might clarify some of the questions.

 

[Myrkk]

Good point! Didn’t think of that, brain is in full on juggling mode at the moment. Multi-tasking is taking a hammering.

 

[Hanuman]

I used to use stress coat and switched to prime around 6mths prior to moving to where I live now.

So prior to moving you used prime for 6 months without issue?
It's confusing, lol. Can I suggest you change 10L of water add only 0.25ml (5 drops) of prime to the bucket that contains the water going in and gauge the reaction of the fish.

I think doing the above might help us start ruling things in or out.

This could be a combination of your new water having an issue and the excess of prime dosing.
As a trial, I would suggest you to bubble your new water overnight with an airstone and add the minimum recommended dose of prime as suggested by @John q. If fish keep reacting the same way then clearly the water could be at falt here and the excess of prime you have been adding so far is just making things worse.

 

[Bradders]

the fish are still a little stressed and panting, so I’m going to wait until they are stronger, then I’ll try this. I really do not want to lose any more.

Have you increased the air within the aquarium to as much as possible? i.e. maximum surface agitation, air stone etc? Sorry if I missed that already, but I will do as much as possible to maximise oxygen exchange at this point as the fish are still panting.

Another thought here is to go and buy some Reverse Osmosis water re-mineralise with something like APT Sky (APT Sky just for convenience, really) so you know you are a) putting in pure water, b) controlling the parameters to some degree, c) removing the old water which potentially could be a cause and d) you do not have to use any water conditioner. You can get 100 litres for under £4 from Spotless Water or some LFS, and Sky is around £15-£20.

 

[G H Nelson]

How is the Cory reacting to these tank conditions?

 

[Conort2]

Can you take some pictures of the stock and the aquarium please?

 

[Myrkk]

The Cory is sitting at the bottom and doing his usual top of the tank darts, albeit a little more often than usual

 

[Myrkk]

Two images, sorry can’t lift the top of the tank at the mo as have a shoulder injury so a pic from underneath

 

[G H Nelson]

The Cory is sitting at the bottom and doing his usual top of the tank darts, albeit a little more often than usual

Did you lose any Cory's after a water change?

 

[Bradders]

I know I sound like a stuck record, but how is the aeration in that aquarium? The pictures don’t show me much.