I need a recommendation on methylene blue

[Melo16]

It turns out that I, for more than two years, have been using methylene blue in aquariums at every water change, because that is what the store told me to do, but now that I look for more information, I see that they say that this is bad for the fish. Would there be a risk of infection or something like that if I stop using methylene blue on these fish that are already used to it?

[nabokovfan87]

Not sure.

I would think the fish would do much better if there wasn't stress, but I understand the concern for how this has impacted their immune system.  Perhaps the best way is to slowly cut back over time?  Instead of every change, start doing it half as much, half doses, etc.

I would also suggest maybe having carbon running on this tank for a while just to help remove meds (once you are done slowly cutting back) and this may also help with some sensitivity issues you might see as a result of this whole ordeal.

Welcome to the forums.  I'm very sorry for the struggle you've had so far.

[Flumpweesel]

How much have you been using? 

I used it in various guises to treat ick and I know they often use it when importing fish (you can see it in some of Corys fish farm tours).

What do the instructions on your bottle say?

I will say take a breath don't worry about what has been done just move forward. I have found fry in water containing the stuff. 

Also have you been using a dechlorinator as well ? I only ask because of the random advice you have been getting from the store.

Also where in the world are you based ? - curious to see if this is a different country different habits thing. It mainly feels like old fashioned advice from the limited med days of fish keeping.

I would probably say steady water change it out if your fish are happy just do your normal water changes but without it. I don't think the fish will notice and you will be there to watch just in case. 

I think it breaks down to some degree in UV anyway ( from a faint memory ) so the levels in your tank might not be as worrying as you think.

[Melo16]

On 7/13/2022 at 5:32 PM, Flumpweesel said:

How much have you been using? 

I used it in various guises to treat ick and I know they often use it when importing fish (you can see it in some of Corys fish farm tours).

What do the instructions on your bottle say?

I will say take a breath don't worry about what has been done just move forward. I have found fry in water containing the stuff. 

Also have you been using a dechlorinator as well ? I only ask because of the random advice you have been getting from the store.

Also where in the world are you based ? - curious to see if this is a different country different habits thing. It mainly feels like old fashioned advice from the limited med days of fish keeping.

I would probably say steady water change it out if your fish are happy just do your normal water changes but without it. I don't think the fish will notice and you will be there to watch just in case. 

I think it breaks down to some degree in UV anyway ( from a faint memory ) so the levels in your tank might not be as worrying as you think.

Hello, thanks for answering. The instructions on the bottle are a bit poor, they only say how much to use, and I do use a dechlorinator. The truth is, I am from Costa Rica, from an almost rural area, it is very difficult to get good advice in pet stores, or good products. For example, there is no way to buy live plants anywhere, and Amazon is a pain and shipping is very expensive here. Where I bought those fish, which have been with me for a long time, and I bought them without knowing anything, like almost all of us started, they only told me to add dechlorinator and methylene blue to each water change. I have become more informed until recently that I began to wish for better conditions for my fish, as I was almost a child when I bought them. Any advice is helpful, you should know that the fish look good, but I know that there are things that need to be learned to improve their quality of life, but here it is complicated, as I already mentioned, due to the lack of products and people to consult.

[Biotope Biologist]

Methylene blue is fine for your fish even over long exposure periods. I wonder if this is left over advice from aquaculture…

 

But I’d stop using it. The reason being is it’s not fine for your beneficial bacteria over long exposure periods. And these are the things actively reducing fish waste in to non harmful byproducts. 
 

Oh and welcome to the forums! You might have better water than most for traditional aquarium fish since they come from very similar areas

[Flumpweesel]

 

On 7/14/2022 at 1:24 AM, Melo16 said:

I am from Costa Rica, from an almost rural area

I new it would be somewhere interesting! 

When I think about how I've kept fish in the past I feel I could have been doing better but we do the best with what we have at the time. 

You haven't done any harm and but now if you stop using it you'll save some money. Good to have you on board. 

It will be fun helping you and seeing how to do things without the luxury of next day delivery. 

[Chick-In-Of-TheSea]

Welcome! You’re at the right place for aquarium advice! This is a friendly environment here. You will enjoy it.

I agree with @nabokovfan87 as far as going to half doses and weaning them off of it completely as they’ve had it in their water for 2 years.