Fish randomly dying / beginner

[KariC]

Hello,

Over the past few years I've set up and taken down a 6 gallon fluval edge and a 5 gallon Marineland portrait aquarium. I currently have the Marineland set up. I have a heater and API master test kit. My water always tests within proper parameters. Temps kept between 74-76 degrees. My problem is I have trouble keeping fish alive. I've had three betas (one at a time) longest one has lived is 9 months. After the last beta death I took down the aquarium for a few weeks and started over. Doing a fishless cycle for a month, testing water then adding three zebra danios and four tetras. Within days the danios died. Replaced two and they also passed within days. One tetra passed after a few weeks. Three tetras remained for two months, no deaths. Added a small rubber pleco which passed after a week. I frequently do 1/4 to 1/2 water changes and continue to check PH, ammonia, nitrites and nitrates with my API master test kit. All is well there.
I love aquariums and am thinking about getting a larger 20-30 gallon tank to see if that's easier to keep. I just don't want to keep killing fish, just on a larger scale

 

[Oblio]

More competent members will chime in on the deaths but I will mention the following:

Larger tanks are easier to keep stable and allow for more fish (see below) - They take up more room and water changes can be a chore without a Python or similar setup.
Danios and many Tetras (what species do you have?) do much better with a larger shoal sizes. A small group will stress the fish, and Danios (others also) get aggressive in small groups.

 

[Oblio]

You mention that your water parameters are proper.
Are ammonia and nitrite at zero?

 

[KariC]

You mention that your water parameters are proper.
Are ammonia and nitrite at zero?

Yes, and highest my nitrate level has been is 20, and that's just recently. I wake up to find a fish dead, no looking sick before hand.

 

[StripySnailGirl04]

Within days the danios died. Replaced two and they also passed within days. One tetra passed after a few weeks. Three tetras remained for two months, no deaths. Added a small rubber pleco which passed after a week.

There can be a few reasons causing fish deaths:
A:Your tank sizes are way too small for your stocking
B: Every fish that you mentioned apart from the plec need to be kept in shoals of 6+
C:What is your pH, GH and KH. Please write exact water parameters.

Welcome to TFF!

 

[KariC]

There can be a few reasons causing fish deaths:
A:Your tank sizes are way too small for your stocking
B: Every fish that you mentioned apart from the plec need to be kept in shoals of 6+
C:What is your pH, GH and KH. Please write exact water parameters.

Welcome to TFF!

My pH is 7.0 - 6.8. Never measured for GH and KH.
Just measured for pH, ammonia 0ppm nitrites 0ppm and nitrates always less than 20ppm

 

[KariC]

My pH is 7.0 - 6.8. Never measured for GH and KH.
Just measured for pH, ammonia 0ppm nitrites 0ppm and nitrates always less than 20ppm

I also have well water. How about the bettas? I had them as the only one in the tank, they don't last long either.

 

[StripySnailGirl04]

I also have well water. How about the bettas? I had them as the only one in the tank, they don't last long either.

Do you use water conditioner?

 

[Naughts]

Do you always use the same supplier? They may sell weak fish.

The bigger tank will be easier on the fish.

 

[Byron]

You mention well water...do you mean a private well that supplies just your house, or municipal water that happens to come from a well? Assuming it is a private well, have you had water tests carried out to see what is in the water? Does it go through any type of filter? Do you drink it?

Also, complete data on the aquarium will help. How often and what volume are water changes; what conditioner do you use (if you do); what substrate and decor is in the tank; any other additives being added to the water? Are there live plants?

Also, it helps to know the numbers of any water tests you can do; sometimes these can clue us in to potential issues.

 

[KariC]

Do you use water conditioner?

Yes I use conditioner

 

[KariC]

You mention well water...do you mean a private well that supplies just your house, or municipal water that happens to come from a well? Assuming it is a private well, have you had water tests carried out to see what is in the water? Does it go through any type of filter? Do you drink it?

Also, complete data on the aquarium will help. How often and what volume are water changes; what conditioner do you use (if you do); what substrate and decor is in the tank; any other additives being added to the water? Are there live plants?

Also, it helps to know the numbers of any water tests you can do; sometimes these can clue us in to potential issues.

Yes, well supplies water to just our house. Water goes through a basic cullagan water filter, yes we drink from it. I do 1/4-1/2 water changes every 3-4 weeks.. I use API tap water conditioner. No live plants, they died too. Plastic decor, sand substrate from petco (rinsed well)

 

[KariC]

Do you always use the same supplier? They may sell weak fish.

The bigger tank will be easier on the fish.

Buy my fish from petco / petsmart

 

[Oblio]

You mention that your water changes are every 3-4 weeks.

Are your ammonia/nitrites zero at just prior to a water change? (3-4 weeks seems a bit long, with such a small tank I would change weekly)

Do the fish deaths tend to happen at a particular period in your water change cycle? (beginning/end)

Are your hands free from any contaminants (lotion, soap etc.) prior to putting them in the tank? This is more crucial with a small tank as any contaminants entering the water will have a higher concentration.

Did you clean your tank or decorations with any soap or chemicals?

 

[Byron]

On the well water...I do not know what the cullagan filter might do in the way of filtering, adding chemicals/salt, etc, so it might help to look into that. For example, water softeners often add sodium chloride (common salt) to negate calcium and magnesium salts, making the water softer, but the sodium chloride salt is harmful in itself over time. Also, if the water has ever been tested for minerals like copper, iron, etc? Copper levels that are safe for humans can be deadly to fish.

Water changes could be more often, once a week is minimum, and half the tank. Obviously if the problem is in the water to begin with, this is not going to solve that, but assuming the water is OK the more you change the better for the fish. The points raised by Oblio in the above post are important, I second that post.

API Tap Water Conditioner (TWC) is good, about the best product we have frankly. Their StressZyme however is not really safe long-term, so I would not use it. Clean water, with only the amount of TWC needed, is the goal.