Keep losing fish with no explanation. Help!

[miaz]

Hi guys
I hope someone out there can help me, I've spent countless hours online and have no answers yet.
I have 2 tanks both completely cycled and been running for about a year. They are very differnt set ups, one with gravel and live plants, one with sand substrate and silk plants. The live planted tank contains guppies and the sand tank contains plattties and baloon mollies. The are both 80l tanks, understocked (never more than 5 small fish in them). Both kept at 25 degrees, with GH around 15.
The issue is that I keep losing fish without explanation. NO signs of injury or obvious illness. In some cases they seem a little skinny and lethargic for a few days, in other cases they are just dead one morning. Sometimes I lose them within a few weeks of bringing them home, sometimes they last a few months. Currentlty I have 1 platty that has lasted the whole year but I have stopped buying new fish as they literally just keep dying.
Now my tap water comes out at pH 7 BUT if you leave it for a few hours it goes up to 7.6, so I thought that my water changes were causing too much of a pH shift (as I often lost fish the morning after a water change). So I switched from doing 30% once a week to 15% twice a week, including a section of gravel vac each time. I test ammonia, nitrite, nitrate and pH every week or 2 and I have only ever had an issue once, which was a weird random pH of 8 situation a couple of months ago in 1 of the tanks.
The really stange thing about my tap water is that despite going up to pH 7.6 when you let it sit it has very low Gh and Kh so I have to add those blue conditioning salts to new water to bring the water hardness up for the livebearers. For the past few months I have been adding easy-life conditioner tonic that the aquarium store told me would help ward off disease among livebearers.
2 days ago I came home to a dead baloon molly. I'd only had him for 1 month, so ok. But now this morning I have found one of my older mollies (he has been happy and energetic living in the tank for 4 months) lying on the bottom with clamped find breathing heavily. I did a water test, no ammonia, nitrite or nitrate. In fact I did my 5% water change last night.
We do not use any perfume or bleach like cleaning products at all in the house, and I wash my hands thoroughly before touching anyhting on the tanks so I doubt any chemicals have gone into the water. I also feed a variety of high protein foods, including frozen brine shrimp as well as slightly boiled spinach and once a eek I give them a fasting day followed by pea the next morning.
I am really quite devestated at this latest loss. I really love my fish, and as I stated before I have stopped replacing them as I feel that no matter what i do I'm bringing home a sweet little fish to its death.
Noting online gives me any understanding of what I'm doing wrong. Has anyone got any ideas?

 

[JettsPapa]

I'm puzzled by you saying you have 0 nitrates. You should be seeing some, especially in the tank with silk plants.

 

[crazycracker]

Did you let them get use to the water before putting them in? Did you buy them from the same store in the same tank? Maybe they're sick. I dont use tap water because I'm scared the conditioner might harm my plants and future fish. I just use spring water.

 

[kallililly1973]

Doing a 5% Wc isn't going to remove anything. I would also stop using the other things your LFS suggested. All you need is a cycled tank, weekly 50-75% WC's a bottle of Prime water conditioner and an API liquid test kit.

 

[miaz]

Sorry that should read 15% water change, I have issues with y keyboard at the monent

Yes

Did you let them get use to the water before putting them in? Did you buy them from the same store in the same tank? Maybe they're sick. I dont use tap water because I'm scared the conditioner might harm my plants and future fish. I just use spring water.

. I dri[ acclimate for around 90 mins before adding them to the tank. And the little guy who is sick now has been happy in there for 4 months

I

Doing a 5% Wc isn't going to remove anything. I would also stop using the other things your LFS suggested. All you need is a cycled tank, weekly 50-75% WC's a bottle of Prime water conditioner and an API liquid test kit.

Id there were a buildup of nitrates wouldn't it show on my API test?

A

Yes
. I dri[ acclimate for around 90 mins before adding them to the tank. And the little guy who is sick now has been happy in there for 4 months

Also the mollies and guppies have come from many different stores over the past year. Like I said sometimes they last only a week or so and sometimes they are fine for several months before suddenly dying

 

[kallililly1973]

The API nitrate test needs to be done exactly to a T or you csan get false readings...but nitrates are far less dangerous than nitrites and ammonia..

 

[miaz]

I'm puzzled by you saying you have 0 nitrates. You should be seeing some, especially in the tank with silk plants.

I sometimes have 5ppm nitrates (A slight orange colour on the API master kit). But as I said my tanks are very understocked and I am religious about changing 15% water every 3 days so it just never builds up I guess.

I have taken water in to be checked in the shop and their readings were the same same as mine

A

I

Id there were a buildup of nitrates wouldn't it show on my API test?

Also, I oroginally used only this basic stuff you have listed (for the first 8-9 months) and had a lot of fish die after water changes. Whcih, as stated I suspect was because of the pH dropping when I add new water at a pH 7

 

[kallililly1973]

My only other advice would be to check your source water to make sure you know whats going back into your tank.

 

[miaz]

My only other advice would be to check your source water to make sure you know whats going back into your tank.

That's my concern, my water source. I'm on mains water in inner suburban Melbourne, so the water source is ok but but I don't trust the old taps here (and there is no chance my landlord cares). That's why I started using easy-life conditioner tonic, it's supposed to neutralise any metals and things. I haven't been able to figure out why my water has low Kh and Gh but high pH. (Tested with and without water conditioner)

 

[Dechi]

I wouldn’t do 2 WC per week, they can be stressful to fish and 15% isn’t enough. I would do 40%-50% every 7 to 10 days. I wouldn’t try to mess with GH and KH. Just buy the fish that suit your PH and they’ll be fine. And stop using this other product from the store.

Make sure you use water conditioner when you do your WC, enough for the whole 20 gallons, even if your only changing 50%.

Having stability in an aquarium should not be complicated.

How do you maintain your filters ?

 

[miaz]

I don't really mess with the filters a lot. They are double sponge filters (https://www.amazon.com/XY-2822-Double-Sponge-Filter-Aquarium/dp/B005VAFGKI). I use a large airpump with 2 outlets to power both tanks. Every couple of months I rinse/squeeze one out in tank water I'm removing (I follow instructions from the aquarium co-op youtube video on maintaining sponge filters), and a few months later I do the other sponge.
The things is my aquariums both seem stable. Apart from the one time I had a ph of 8 instead of the normal 7.6, both the tanks always have the same readings (0 ammonia, 0 nitrites, and 0-5ppm nitrates, ph 7.6 and IF I dont use salts Kh and Gh around 3). I've taken water in to be tested at the shop several times and it's always the same. I dont have problems with algae or anything. The only thing people in the aquariums could suggest was a heavy metal or something in the tap water, hence the easy-life tonic I started using a few months ago.

 

[PascalKrypt]

So if it takes that off your mind, your source water is nearly the same as mine in terms of the basic parameters (I have PH 7.8, GH 4 and KH 4, thereabouts). I have absolutely no trouble keeping even more sensitive fish with these parameters. I also have no trouble keeping livebearers (though I suspect they are a little more sensitive to problems).

What kind of feeding regime do you have? This is something that you haven't mentioned. Could you also provide us with an (approximate) timeline of all the fish that entered this tank - when did you add them, were they QT'd, were they treated for anything (what with and how long), when did they show symptoms and when did they die? Amounts of fish as well. That gives a better picture of what sort of thing we are dealing with.

First thing to rule out is a build-up of some kind of toxin or trace material. Start doing 75% water changes once a week, religiously. See if that solves the problem after a month or two (though you should get new fish to test this, as those living in your current water may already have been compromised). Do you ever vacuum your substrate? What kind decorations do you have? You may want to take out all the artificial decorations and vacuuming alternating halves of your substrate every WC and see if that changes anything.

There is always a possibility your water is contaminated with something slowly harming your fish. Could be some kind of substance the 'cleanser' is missing, perhaps some kind of mold in the pipes? Just spitballing, but is it possible for you to get a different water source (even if it means buying bottled water) for at least one of the tank and see if doing WCs with only that water for the next few months will make the problem go away?

Are you tanks second-hand? If they are, there is always the possibility the seals are contaminated with something by a previous owner.

Final thing I could think of is that there is some kind of illness in your tank (you don't seem to QT newly bought fish?) that kills quickly when it strikes but takes a toll with long intervals. It isn't impossible but this is the least likely of the explanations so try the above first, if that still doesn't work then wait till all fish are dead (they will all have been compromised), dismantle your tanks, let everything dry for no less than 30 days (kills absolutely every aquatic pathogen including myco), do a thorough rinse of everything and start anew.

 

[Dechi]

What’s the longest time you’ve been without using salt and did you have deaths also when not using any for a long period ?

Do you know of a fish store or someone who successfully keeps fish on the same water supply you use ?

 

[GlennO]

You said your GH is low, how low exactly? Livebearers can be more susceptible to illness if kept in very soft water.

Edit...I think you said GH of 15...is that ppm?

 

[miaz]

You said your GH is low, how low exactly? Livebearers can be more susceptible to illness if kept in very soft water.

Edit...I think you said GH of 15...is that ppm?

Yes, when I add the blue crystals to make it 15. Out of the tap it's 3 and since I was losing a lot of livebearers I started using the cru=ystals about 4 months ago. Unfortunately it has made no difference

I

What’s the longest time you’ve been without using salt and did you have deaths also when not using any for a long period ?

Do you know of a fish store or someone who successfully keeps fish on the same water supply you use ?

I don't know anyone who keeps fish (none of my neighbours do). I never used to use salts, I only started using the blue crystals about 4 months ago as I thought that lack of salt and minerals with the livebeaers was the problem

So if it takes that off your mind, your source water is nearly the same as mine in terms of the basic parameters (I have PH 7.8, GH 4 and KH 4, thereabouts). I have absolutely no trouble keeping even more sensitive fish with these parameters. I also have no trouble keeping livebearers (though I suspect they are a little more sensitive to problems).

What kind of feeding regime do you have? This is something that you haven't mentioned. Could you also provide us with an (approximate) timeline of all the fish that entered this tank - when did you add them, were they QT'd, were they treated for anything (what with and how long), when did they show symptoms and when did they die? Amounts of fish as well. That gives a better picture of what sort of thing we are dealing with.

First thing to rule out is a build-up of some kind of toxin or trace material. Start doing 75% water changes once a week, religiously. See if that solves the problem after a month or two (though you should get new fish to test this, as those living in your current water may already have been compromised). Do you ever vacuum your substrate? What kind decorations do you have? You may want to take out all the artificial decorations and vacuuming alternating halves of your substrate every WC and see if that changes anything.

There is always a possibility your water is contaminated with something slowly harming your fish. Could be some kind of substance the 'cleanser' is missing, perhaps some kind of mold in the pipes? Just spitballing, but is it possible for you to get a different water source (even if it means buying bottled water) for at least one of the tank and see if doing WCs with only that water for the next few months will make the problem go away?

Are you tanks second-hand? If they are, there is always the possibility the seals are contaminated with something by a previous owner.

Final thing I could think of is that there is some kind of illness in your tank (you don't seem to QT newly bought fish?) that kills quickly when it strikes but takes a toll with long intervals. It isn't impossible but this is the least likely of the explanations so try the above first, if that still doesn't work then wait till all fish are dead (they will all have been compromised), dismantle your tanks, let everything dry for no less than 30 days (kills absolutely every aquatic pathogen including myco), do a thorough rinse of everything and start anew.

1. Cleaning- I vaccum a section of substrate with every water change (about a quarter of the tank) so that the hole thing is vacuumed about every 2 weeks. Ornaments are silk plants and a half terracacotta pot thing in 1 tank (baloon mollies and platies) and live plants, and driftwood the other tank (guppies).
2.Feeding- twice per day for 6 days a week Then a day of fasting followed by slightly boiled pea to ensure no constipation (as I thought maybe that was the problem). Food is varied, of 12 feedings per week I feed frozen brine shrimp twice and frozen blood worm twice a week, boiled spinach twice a week and the rest of the time small nutrafin pellets. All fish eat enough (noone is bullied and misses out).
3. I do use a 30l quarantine tank, I leave new fish in there for 3 weeks before they enter the main tank. Occasionally I lose them straight away in the QT, usually they seem absolutely fine but they only survive a few weeks or a few months in the main tank. Once I bought 4 guppies and they all died in the QT within the first few days so I never purchased from that shop again. Early on when I had my first mollies they clearly had worms (very long white strings hanging out) and I used 'blue planet fluke and tapeworm',dosed twice as per instructions and the worms cleared up. Those mollies have long gone now though.
A few months ago when I noticed a fish getting slow and lethargic and he was looking quite thin even though he was eating. I put him in the QT and treated him with API general cure for wasting disease as the symptoms seemed to match what I read online and everyone raves about that stuff (I had to buy it from the US as it's technically not legal here). He seemed to get better and after a few weeks I put him back in the main tank where he then suddenly died a week later.
It would be impossible for me to remember all of the others, when 1 dies my bf gets me another one to cheer me up (even though I keep telling him not to) and so the cycle continues. Although I have now made it clear that I dont want to bring any more fish to their death.
4. The tanks: 1 was brand new and 1 was second hand and I cleaned it with vinegar and dried it outside before using it. Both were cycled for around 6 weeks using ammonia and quickstart a year ago.

While some deaths I can possibly attribute to bullying, the bullies themselves have long ago died. The few fish I have left now all get along really well, yet the deaths continue.

I'll try removing the terracotta pot and try some large water changes. If I Use bottled water should I be adding more crytals/salt? I'll try that in 1 tank, but it's gonna be tough economically but also logistically to carry all that water home (don't have a car as I live in inner Melbourne) but I'll see if it helps.

Oh but as mentioned in my original post I do have a platty which has survived almost from the beginning without ever gettting sick. So whatever it is he isn't impacted.

 

[GlennO]

Yes, when I add the blue crystals to make it 15. Out of the tap it's 3 and since I was losing a lot of livebearers I started using the cru=ystals about 4 months ago. Unfortunately it has made no difference

hmm..I'm thinking it must be dH. I doubt that Melbourne's water would be that soft. 3ppm is almost RO water and 15ppm is still very soft. You need to get it over 60ppm (3.4 dH) at least.

 

[miaz]

I use the API Gh and Kh test kit where u count the drops until the vial changes colour. I've read that livebearers prefer 12-20 hence the use of the salts. that came about because when I took my water for a full spectrum test they told me I only had a 3 on hardness and I purchased the test kit and salt then. To me it seems strange to have soft water but a high pH, I cant find any explanation online.

 

[GlennO]

How many drops before it changes colour? 3 drops = 54ppm (3 dGH).
A pH of 7 or even 7.6 is not 'high' in my view. My tap water is around 7.4 with a GH of about 80ppm.

 

[miaz]

As I said earlier 3 Gh (3 drops) without salts, and now that I use the salts I keep it around 15, as everywhere online says that that livebearers should be kept at 12 at least, and I had thought that was the problem. Some people on such forums said their immune systems would be weak if kept in water with too low Gh. However, I now doubt this has anything to do since the deaths haven't stopped, including with fish I bought since including the crystals.

 

[GlennO]

Ok I agree the GH shouldn't be an issue. Neither should the pH.