Guppy turning black... ish?

[misshedge]

My male fancy guppy (Slash) has been doing absolutely fine, and I've had him for about four weeks or so. Although, just recently, I've noticed a spot on the front of his dorsal fin that has turned solid black in the morning, and a more transparent grey in the evenings. It is also on a thin line on the top and bottom of his caudal (?) fin.
Slash is eating fine and swimming around a lot, but I'm worried about his health and if it will affect the other fish.
I have four neon tetras, a female molly, and a bristlenose pleco in the same tank
I have done water changes (about 20%) as well.

Please help! I've had bad luck for the past few weeks with fancy guppies and Slash is my last remaining one. Thanks!

If you need me to send pictures I'll upload them.

 

[NickAu]

Hi we need a photo.
Also you have problems with stocking. Tetras are soft water fish live bearers like Guppies and Mollies are hard water fish.

What are your water parameters.
Ammonia
Nitrite
Nitrate
Do you have soft or hard water
Is the tank filtered
Has it got a heater
What is the water temp
How often do you change water
How much do you change
Is the tank cycled
What additives do you use.

 

[misshedge]

Hi we need a photo.
Also you have problems with stocking. Tetras are soft water fish live bearers like Guppies and Mollies are hard water fish.

What are your water parameters.
Ammonia
Nitrite
Nitrate
Do you have soft or hard water
Is the tank filtered
Has it got a heater
What is the water temp
How often do you change water
How much do you change
Is the tank cycled
What additives do you use.

Thank you for the stocking advice, I'll look into changing it up. Also, I'm new to owning fish, so some of these I may not know.
I'm not sure of the first four but I will look into them as soon as possible.
It is filtered, heated (78 f), water is changed 20% about every week (I try to keep it consistent), the tank is not cycled, and I do not use additives. The picture will be posted shortly

 

[NickAu]

Ok you have some serious problems.

How big is the tank?
How long has it been set up.

Once I know the answers to these 2 questions I will have more info for you,

 

[misshedge]

Ok you have some serious problems.

How big is the tank?
How long has it been set up.

Once I know the answers to these 2 questions I will have more info for you,

The tank is a 13 gallon and it has been set up for about.. 10-12 weeks? I'm not sure.
The picture will not send to my email so I'll get it as soon as possible.

 

[misshedge]

For more information (not sure if this is relevant) the pH is normal (around 7.2).

 

[NickAu]

water is changed 20% about every week (I try to keep it consistent),

Up that to 50% once a week, not about once a week but minimum once a week.

What type of water conditioner do you use?

I would take a sample of water to local fish shop and get them to test the water, get the actual numbers.

 

[misshedge]

Up that to 50% once a week, not about once a week but minimum once a week.

What type of water conditioner do you use?

I would take a sample of water to local fish shop and get them to test the water, get the actual numbers.

Thank you so much for the advice! Also, will moving the fish back and forth stress them out? Just wondering. I do not use water conditioner because I use spring water, but I have a sample packet of it from getting the tank if needed.

 

[NickAu]

I do not use water conditioner because I use spring water,

Bottled spring water? this could be a problem.

I would not recommend bottled water simply because you do not know whats in it or not in it, Bottled water is not regulated or tested, so the water parameters are unknown. It could have anything added to it like vitamins, flavors, preservatives, colors, or other additives.

 

[misshedge]

I use the jugs of spring water, yes. I have the picture now as well. The light alters it, but in this photo, it is transparent grey. The small black dot on his body is natural coloring (it was there when I got him).

 

[NickAu]

Whats wrong with your tap water?

 

[misshedge]

Whats wrong with your tap water?

Nothing is wrong with the tap water, I can use it if necessary. Do you know anything about the black spot on his fin? It may be just coloration, but i'm not sure?

 

[NickAu]

Without seeing it I cant say.

 

[misshedge]

Without seeing it I cant say.

I have the picture on the original post.

 

[NickAu]

Hi

Sorry I cant tell from that photo.

You should be able to find out your tap water parameters from your suppliers website. I think your biggest problem is the spring water and a lack of water changes, Once we get the water issue sorted out and you have the right fish for the water conditions everything will be fine.