Mollie with sore on one side...pic included

[cleomccabe]

Hi all.

I was just doing my 10 year old son's water change and while sitting and admiring the tank, noticed my one Mollie has a red sore on one side near the gill. My son told me it has been there for at least a month when I asked so not an emergency. Fish (about 12) all look extremely healthy. We have mostly Mollies and one monster loach and a few randoms. No new fish since July.

Tank 29 gallon, planted, 2 years old.

You can see the sore on the pic. Sorry it is so big.
I just changed the water and have been doing 30% water changes weekly to battle my murky green water. My water is very hard, pH hangs around 7 and nitrates hang around 10-15 (my tap water is high itself so it won't go lower) Nitrites and NH3 are zero.

A few weeks ago I pulled all my plants and repotted them in the Fluval soil in little pots so I could vacuum the gravel more efficiently to fix the green water. I haven't used any chemicals for the algae and seem to have gotten the upper hand with the vacuuming.

Should I treat the whole tank for possible infection or pull him out and treat him solo? I have a 10 gallon I can set up. Recommendations

 

[Colin_T]

Hi and welcome to the forum

Don't add any medications unless you know what the problem is. More fish die from being poisoned by chemical medications and poor water quality, than from the actual diseases.

Can you post some clear pictures showing the fish from the side so we can see the injury?
Maybe do a huge water change before taking the pictures so there is less algae in the way.

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If you add some floating plants like Water Sprite (Ceratopteris thalictroides/ cornuta), it will use up nutrients and reduce light, and help get rid of the algae problem. You can also add more plants in pots to help.

If you do a 75% water change and gravel clean the substrate every day for a week, that should also help get rid of the algae and might help the fish.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

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What sort of filter is on/ in the tank?
How often do you clean the filter?
How do you clean the filter?

 

[CaptainBarnicles]

What am I looking at?

 

[Colin_T]

What am I looking at?

white molly with hole in gill cover

 

[emeraldking]

I'm sorry but I just don't see the spot you've mentioned.

 

[Colin_T]

 

[cleomccabe]

Thank you for the responses.

I had read that green water was NOT bad for the fish as far as water quality hence why I have been a little slow with getting the algae under control with just weekly 30% water changes. I finally gave in and spent about 3 hours last weekend doing the plant repotting and huge water change (I changed out 30-40% of the water, three times in a row so I could keep vacuuming the gravel.

Do you think the green water could have been a cause? I am really diligent about water changes so my water quality is great except for the green water (which obviously mean I have a lot of nitrates).

I will try for another picture. I had just done a 30% water change and it is the clearest it has been in 2 months. The frequent water changes are doing the trick and I will continue every few days. I have a really good light on top and the combo of not being able to vacuum around the plant roots and intense light for half the day was causing the green water I hope. I bought a timer for the light and that will help as well I hope.

As far as specs...I use a Marineland Penquin 350. Temperature is 77 degrees. The filter is new as of July and sized appropriately for the tank. I change the filter monthly except for the past 2 weeks, I changed it weekly. Last week, I added a nitrate sponge mechanical filter as a prefilter-was supposed to catch bigger things that may raise nitrates like leaves etc but I removed it yesterday.

Thanks. Will go try to get a better pic. Maybe change more water ugh. At least I have some muscles from the lifting.
Edited...Got the pic.

Also editing to add that I use Prime to dechlorinate.

 

[connorlindeman]

Thank you for the responses.

I had read that green water was NOT bad for the fish as far as water quality hence why I have been a little slow with getting the algae under control with just weekly 30% water changes. I finally gave in and spent about 3 hours last weekend doing the plant repotting and huge water change (I changed out 30-40% of the water, three times in a row so I could keep vacuuming the gravel.

Do you think the green water could have been a cause? I am really diligent about water changes so my water quality is great except for the green water (which obviously mean I have a lot of nitrates).

I will try for another picture. I had just done a 30% water change and it is the clearest it has been in 2 months. The frequent water changes are doing the trick and I will continue every few days. I have a really good light on top and the combo of not being able to vacuum around the plant roots and intense light for half the day was causing the green water I hope. I bought a timer for the light and that will help as well I hope.

As far as specs...I use a Marineland Penquin 350. Temperature is 77 degrees. The filter is new as of July and sized appropriately for the tank. I change the filter monthly except for the past 2 weeks, I changed it weekly. Last week, I added a nitrate sponge mechanical filter as a prefilter-was supposed to catch bigger things that may raise nitrates like leaves etc but I removed it yesterday.

Thanks. Will go try to get a better pic. Maybe change more water ugh. At least I have some muscles from the lifting.
Edited...Got the pic.

Also editing to add that I use Prime to dechlorinate.
View attachment 151306

That's a better pic.

It looks like an ulcer to me.

Most of the time ulcers are caused by stress. This can be from bad water quality. If the ulcer is very bad you may have to use an antibiotic but don't use that until someone more experienced than me says to
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Before doing that, you could use a topical swab. Hydrogen peroxide at 3-6% solution, iodine, mercurochrome or potassium permanganate is used to swab the ulcer using a Q-tip (cotton bud) dipped in the solution. Be very careful not to get it in a gill or eye. Put the fish in a net to and make sure that the liquid will run away from the eye or gill instead of going in to it.
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You could also do a salt bath.

 

[Colin_T]

Green water is fine for fish and did not cause this.

You need to stop replacing the filter media. When you throw the old media/ materials away, you get rid of the beneficial filter bacteria that helps keep the water clean. When that happens you get ammonia and nitrite spikes and they can cause green water to occur.

If you have a filter that has pad/ cartridges that need replacing, get a sponge for another brand of filter and cut it to shape with a pair of scissors. Use sponges and they will last 10+ years and only need replacing when they start to fall apart. Sponges get squeezed out in a bucket of tank water and re-used. The bucket of dirty water gets poured on the lawn or garden.

I use AquaClear sponges but there are other brands too. Just find one that is bigger than your filter and cut it to fit.

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The hole in the gill cover looks like a bacterial infection that has caused an ulcer. Salt might treat it but you will need to get the salt level up. If salt doesn't fix it, you will need to use a broad spectrum fish medication or anti-biotics. But save the anti-biotics till last and use them in a bare tank so they don't wipe out the filter bacteria.

 

[Colin_T]

SALT
You can add rock salt (often sold as aquarium salt) or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate (4 heaped tablespoons per 20 litres) will affect some plants and some snails. The lower dose rate (1-2 heaped tablespoons per 20 litres) will not affect fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

When you first add salt, add the salt to a small bucket of tank water and dissolve the salt. Then slowly pour the salt water into the tank near the filter outlet. Add the salt over a couple of minutes.

 

[cleomccabe]

Thank you Colin for the detailed info. I only changed the filter twice because there was a ton of chunks in it from the plant switch into pots. Otherwise it is a monthly change. I do agree the crazy gravel vacuuming plus filter change was probably overkill but this ulcer predated all the water changing. I usually wait a day or two after water change to change the filter to allow repopulation of the nitrifying bacteria back into the tank but last week was a big change and I didn't wait. I am glad that my water is looking good again-that was my first time dealing with algae other than small amounts on the glass.

I have 2 gouraminis, one scissortail, one guppie and the rest are Mollies. I also have a dojo loach that I am very attached to so I am nervous about the salt. I may set up a hospital tank tomorrow (getting snow-yay) and just treat the smaller tank individually without risks to my non livebearers and plants. I will siphon the existing water into the 10 gallon to prevent added stress. It will be easier to do smaller water changes and keep track of the salinity. I use reef salt in my hermit crab vivarium so ready to go on that end.

Thank you again for your reply.

 

[Colin_T]

I only changed the filter twice because there was a ton of chunks in it from the plant switch into pots. Otherwise it is a monthly change.

Don't change the filter media at all unless it is literally falling apart. Then replace it with sponge.