Keep Losing Guppies

[WCrimi]

I have a community fish tank (40 gallons) with various types of guppies, platies, mollies, neons, catfish, apple snails etc.. for about the last 6 months. The tank is generally healthy with no ammonia spikes and a PH level that varies between 6.8 and 7.0 .

I lost 2 mollies and 1 neon over 6 months, but generally everyone is thriving....except my guppies. The snails are especially thriving. I just got a batch of about 50 babies that are doing great. But my guppies keep dying. I lost 2 last night.

The symptoms are generally the same each time.

A guppy will look a little disoriented when it's feeding time. It will swim around and come to the surface like it knows it's feeding time, but it won't actually eat. Then after a day or two it starts getting sluggish and weaker until it eventually dies. Sometimes the females also seem to lose their color a little and look pale before they die.

I've bought guppies from different pet stores. So it's not like I just got a bad batch. I've had problems with every batch.

The only thing I can think of is that the PH in my tank has a tendency to fall. The PH is 6.8 out of my tap. I let it stand for a few days before I do a partial water change each week. The tank water PH will tend to fall further if I don't add a little baking soda every few days. I try to keep it in the 6.8 to 7.0 range. I guess it could be PH, but it seems like something else is going on or I don't think it would just be the guppies having major issues.

Any thoughts?

 

[Guppylover3x]

I have a community fish take (40 gallons) with various types of guppies, platies, mollies, neons, catfish, apple snails etc.. for about the last 6 months. The tank is generally healthy with no ammonia spikes and a PH level that varies between 6.8 and 7.0 .

I lost 2 mollies and 1 neon over 6 months, but generally everyone is thriving....except my guppies. The snails are especially thriving. I just got a batch of about 50 babies. But my guppies keep dying. I lost 2 last night.

The symptoms are generally the same each time.

A guppy will look a little disoriented when it's feeding time. It will swim around and come to the surface like it knows it's feeding time, but it won't actually eat. Then after a day or two it starts start getting sluggish and weaker until they eventually die. Sometimes the females also seem to lose their color a little and look pale.

I've bought guppies from different pet stores. So it's not like I just got a bad batch. I've had problems with every batch.

The only thing I can think of is that the PH in my tank has a tendency to fall. The PH is 6.8 out of my tap. I let it stand for a few days before I do a partial water change each week. The tank water PH will tend to fall further if I don't add a little baking soda every few days. I try to keep it in the 6.8 to 7.0 range. I guess it could be PH, but it seems like something else is going on or I don't think it would just be the guppies having major issues.

Any thoughts?

Hello and welcome to the forum
Im sorry to hear of your difficulties. The guppies and mollies require different PH levels to the neons unfortunately. While neons do well at PH ranges of around 6.5 - 7 guppies, mollies and platies proffer ranges of around 7.5 - 8. If you could post the usual ranges for your tap water source on here I’m sure other members could advice further. You can get this information from your local water supplier. This forum is full of very knowledgable fish keepers and there’s lots to learn. Best of luck.

 

[WCrimi]

Thanks.

The tap water comes out at 6.8 fairly consistently. I push it up to about 7 with baking soda because I read that 6.8-7.0 is the bottom of the range for the guppies and others but not too far up because of the neons.

The strange thing is that I've had guppies in the past that did quite well in my tap water without even worrying much about PH. They were probably always in 6.8 water or even lower and did fine. They would breed and the babies would do fine also.

One other thing is that I don't have an air stone, but I do a partial water change (25%) every week. My under water filter keeps the surface moving a bit also. I'm wondering if no air stone is an issue.

 

[Colin_T]

Post a picture and short 20 second video of the fish so we can clearly see the issue.

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Add some limestone, dead coral skeleton or coral rubble, or shells to the tank to stabilise the pH so it doesn't fluctuate.

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What is the ammonia, nitrite, and nitrate in the tank water? We want the results in numbers.

What is the GH (general hardness) and pH of your water supply. This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

Livebearers (guppies, platies, mollies swordtails) naturally occur in hard water with a GH above 200ppm (250ppm for mollies) and a pH above 7.0. If you pH is dropping over the course of a week then you probably have very soft water and that is going to be a problem for them.

Tetras and most catfish come from soft water with a GH below 150ppm and a pH below 7.0.

 

[WCrimi]

Ammonia - 0
PH from tap 6.8
PH in Tank 7.2 as a result of adding baking soda

Nitrite and Nitrate 10

I don't understand the GH/KH tests.

I tested KH and it took 3 drops for the water to change color

I tested GH and no matter how may drops I added it did not change color. I went all the way to 32 drops and then gave up. So there is either something wrong with my test kit or I don't know what to tell you. I also don't
understand how those drop counts are related or how to calculate the GH or KH based on the chart even if the test did work.

In the mean time I added some coral to the tank, but I don't think it's helping much or at all with the falling PH. I still had to add some baking soda to the tank today top keep the PH at near 7.2

 

[Essjay]

Which brand of tester are you using for GH and KH? Most of them work the same way but there may be some that are different.

The majority of liquid GH and KH testers are titrations. This means you add the reagent until there is a colour change. The instructions will tell you what the colour change is.
I am familiar with the API testers. The GH tester turns orange with the first drop, then turns green at the end point. I always find this difficult to see the colour change with soft water as the colours are so pale. It is easier to see if you remove the lid, stand the tube on something white then look down into the tube.
But when GH is very low - below 1 dH - the first drop turns the water very pale olive green. The water in the tube never turns orange.

Is this what you are seeing? What is the colour change supposed to be according to your instructions?

 

[FishGuest5123]

I was going to ask the GH too. I have had the same issue in losing guppies. They just aren’t as hardy as they use to be. Very frustrating!

 

[Colin_T]

If your pH is still dropping after you added some coral rubble/ dead coral skeleton, then add some more. Monitor the pH over a week and if it continues to drop, add more coral, shells or limestone until the pH stabilises and doesn't drop.

Limestone is generally cheaper than coral or shells but they all do the same thing (neutralise acids in the water and stabilise the pH).

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If you have 10ppm of nitrite, that will be a problem to the fish ad indicates the filter is not established or something has happened to it.
What sort of filter is on the tank?
How often do you clean the filter and how do you clean it?

 

[WCrimi]

"Which brand of tester are you using for GH and KH? Most of them work the same way but there may be some that are different."

I'm using API, but it's an old test kit.

When I tried to test GH, the water turned orange and stayed orange no matter how many drops I added. I suspect there's something wrong with the test kit.

 

[Colin_T]

Check the expiry date on the test kits.

If you have access to distilled water you can check the GH and KH of that. Distilled water should have a pH of 7.0 and 0 GH and 0 KH.