4 different fish found dead, not sure whats killing them ??

[Goose3080]

a few days ago 1 of my clown loaches died, this was no mystery, I could tell he was about to die due to erratic behaviour, did try to save him by putting him in a hospital tank but it was a little too late, he passed away that night, he was fairly new to the tank.

2 days ago I came home to find one of my guppies stuck to the side of my wavemaker, the only way he could of got there is to have somehow died and got sucked towards it.

yesterday evening out of the blue I found one of my dwarf gourami's dead floating around the tank, I only had 2 of these fish, started looking for the other and couldnt find it anywhere, I just thought he was hiding really well as it quite a heavily planted tank, I figured he would appear today sometime, this morning ive had another look and discovered him laying on the bottom of the tank, looks like hes been dead for days and the other fish have been having a go at him.

All of my water parameters check out perfect and im doing 2 x 20% water changes a week.

The tank is a Fluval 240 litre roma, I brought it 2nd hand, I did have 2 small holes in one of the lids (the previous owner made) I guess these were for feeding or something, but I have caught my cats sitting on top of the tank sticking there paws in, I just wonder if theyve been trying to catch the fish and hurt a few in the process, or if maybe the clown loach that died brought something else into the tank with him, I have since sealed up the 2 holes in the lid just in case the cats are the culprits.

 

[Ichthys]

What are your water parameters?
What fish are in the tank?

 

[Goose3080]

What are your water parameters?

Ammonia = 0
Nitrite = 0
Nitrate is 5 to 10ppm depends on the day, feeding day its goes upto about 10ppm non feeding days it drops to 5ppm, they get fed every 3 days.
PH = 7.5
KH = 6
GH = 11

Im running 2 external filters, an all pond solutions EF-250 and fluval 307, they are hooked together, the all pond isnt under power, its ust being used as a pre filter, and im using the drilled bottom ports.

EDIT: im also adding 5ml of Seachem flourish Excel (CO2) everyday and 5ml of Seachem Flourish (fertiliser) twice a week for the plants, O2 levels check out fine too at around 8mg.
I use Seachem Prime to treat my tap water which I stick a heater in for a day or 2 before adding to the tank.

 

[Slaphppy7]

Cat paws that are dunked into a tank could potentially introduce a myriad of problems, IMO

Indoor cats, indoor/outdoor?

Anything the cats have stepped in/scratched at/climbed on could have have introduced toxins into the tank

Kitty litter surely has ingredients I would not want in my tank...perfumes, disinfectants, whatever

Just a guess, given the circumstances....the stress alone of a cat reaching into a tank could harm fish, I would think

 

[Goose3080]

Cat paws that are dunked into a tank could potentially introduce a myriad of problems, IMO

Indoor cats, indoor/outdoor?

Anything the cats have stepped in/scratched at/climbed on could have have introduced toxins into the tank

Kitty litter, most certainly

Just a guess, given the circumstances....the stress alone of a cat reaching into a tank could harm fish, I would think

Never thought of that, they are indoor cats only, but yes they use natural cat litter, regardless I did think maybe they were the culprits, ive tonight sealed up the 2 holes that were in the lid and ordered a new section for a more permanent solution.

As per the pictures below, its taped on both sides of the hole with a thin piece of plastic between the layers of tape, the tape is extra held of with epoxy so its not coming off anytime soon, but just a temp solution until the new lid section arrives.

 

[Slaphppy7]

I would do a LARGE water change, be sure to treat with water conditioner accordingly, and match the tap temp to the tank temp as closely as possible

Your patch jobs are fine, as long as the epoxy is on the outer part of the lid

 

[Goose3080]

I would do a LARGE water change, be sure to treat with water conditioner accordingly, and match the tap temp to the tank temp as closely as possible

Thank you, I do have 2x25 litre bottles of de-ironished water heated up already which I brought today, mainly for the bottles to aid with larger water changes, but may as well use the water in them and also a bottle of tap water (treated) currently being heated.

EDIT: just too add, I did do a partial change yesterday, but only 10%, I also cleaned both filters in the water I removed from the tank and replaced the filter floss in both filters yesterday as they were looking a bit worse for wear.

 

[Slaphppy7]

Thank you, I do have 2x25 litre bottles of de-ironished water heated up already which I brought today, mainly for the bottles to aid with larger water changes, but may as well use the water in them and also a bottle of tap water (treated) currently being heated.

Consider getting that Python water changer I mentioned in another thread, if you have a tap nearby with the right kind of faucet

WCs are simplified, significantly

 

[Goose3080]

Consider getting that Python water changer I mentioned in another thread, if you have a tap nearby with the right kind of faucet

WCs are simplified, significantly

I did have a look at it, but my nearest tap is 35 feet away in the kitchen, my tank is in the living room at the furthest point from the kitchen.

 

[Slaphppy7]

I did have a look at it, but my nearest tap is 35 feet away in the kitchen, my tank is in the living room at the furthest point from the kitchen.

They are available in 50 foot lengths: https://www.amazon.com/dp/B000255NXM/?tag=ff0d01-20

From what I understand, tap water from water heaters in the UK for home use may or may not be suitable for using in aquariums, depending on the style of water heater, though

@Essjay can advise on this much better than I can

 

[Goose3080]

They are available in 50 foot lengths: https://www.amazon.com/dp/B000255NXM/?tag=ff0d01-20

From what I understand, tap water from water heaters in the UK for home use may or may not be suitable for using in aquariums, depending on the style of water heater, though

@Essjay can advise on this much better than I can

Yes thats correct, the hot water is only suitable if you have combi boiler ~(it heats the cold water as it comes through), if you have a storage tank as I do, then its no good, you can only use the cold water supply and heat it.

 

[Slaphppy7]

Yes thats correct, the hot water is only suitable if you have combi boiler ~(it heats the cold water as it comes through), if you have a storage tank as I do, then its no good, you can only use the cold water supply and heat it.

Understood

Get that WC done, with what you have available now...and I'd do them at least daily, for a few days, anyway

WC's done correctly never hurt

 

[Goose3080]

Understood

Get that WC done, with what you have available now...and I'd do them at least daily, for a few days, anyway

WC's done correctly never hurt

I will do, thank you.

 

[Slaphppy7]

I will do, thank you.

More than welcome

 

[GaryE]

If the loach had been in the tank for less than 3 weeks, chances are it brought something in. What? Who knows. When things slip through QT, sometimes they have to burn themselves out, painfully.

I once had an entire cat fall in a tank, and both she and the fish were fine.

Go with those water changes - it's the best thing to do, but don't be surprised if the losses continue.