Have I Killed My Cycle?

[fisshboy]

Hi all quick question, noticed one of my mollies had a little bit of fungus today so erlier i did. 50% water change and dosed the tank with king british methylene blue. I was a bit shocked at how blue it actually went but left it anyway then did some reading and read that it can kill your cycle? I have 2 Fluval u4 filters running in my 200L but anyway looked at the tank about an hour later and most of my fish was laying at the bottom on the sand not moving so i decided to do a 60% water change left the tank a little bit then did another 50% water change to try and remove the methylene.

My water stats now right after the changes are

Amonia-0.25
Nitrite-0.50
Nitrate-5.0
PH-6.6

Will this have killed all my good bacteria in an hour or so? Was i too late and have to endure the pain of a 6 week fish in cycle? Anyone thats used it would be a great help as iv heard rumour that the king british claim it wont harm ur good bacteria.

Thanks in advance

Fisshboy

 

[techen]

I've used meth blue before, I hear it can kill off you bacteria but you'll just have to check.

 

[fisshboy]

Thanks for the quick reply what will be the most obviouse sign of it going wrong?

 

[eaglesaquarium]

Well, the fact that you are getting readings for ammonia and nitrite would be a solid indicator that there has been at least SOME die off.  The good news is that you are showing some nitrite, which means you have at least SOME ammonia oxidizing bacteria.  The bad news is that you may have completely killed off the nitrite oxidizing bacteria.  Only time will tell.  It won't take 6 weeks or anything like that but you'll need to monitor it daily... If you have PRIME which can help you deal with the ammonia and nitrite while the bacteria build back up again.

 

[fisshboy]

Yeah i use prime iv dosed it at double the dosage just to be sure did it straight away after

Thanks

 

[fisshboy]

Hi all, tested again this morning result are;

Amonia-0.25ppm
Nitrite-1.0ppm
Nitrate-5.0ppm
PH-6.4

Does this indicate that its gone back a little to the nitrite phase? The .25 amonia id always present as its in my tap water

Thanks

 

[eaglesaquarium]

Even if its your tap water, your bacteria in the tank should be processing that ammonia.  With your pH at 6.6 it isn't cause for alarm, as the vast majority of the ammonia is in the ammonium form, and not toxic.  The nitrite on the other hand is the bigger concern.  You are still going to need to keep up with the water changes and increase aeration for a bit.
 
It shouldn't take too long.  In the meantime, decrease your feeding a bit to give the bacteria a bit of a chance, and do a thorough gravel vac when doing the water change to remove as much detritus as possible - even if you don't think there is much there.  ANY will produce ammonia, and you need to decrease the ammonia production in the tank as best you can!

 

[TwoTankAmin]

Unlike ammonia, nitrite become more toxic the lower the pH goes.
 
If your fish are acting normally I would try to hold off on the water change unless the nitrite goes higher. I assume you are using an API test kit like many on the site and that overstates the nitrite becasue of the testing scale it uses. However, if your fish show any signs of dificulty breathing or lose interest in food its time to change water for sure. Increasing aeration wont help in such cases but adding a bit of salt can. The salt basically blocks the nitrite. This is only a short term remedy and the salt should not remain in the water longer term.M
 
I have used Methylene Blue for years and not lost bacteria. It is often used as a way the get more oxygen into the water as well as an antifungal etc. Except for hatching out eggs, I prefer using Maroxy by Mardel to treat funus.

 

[byork]

Did you check your parameters before adding the methylene blue? You need to keep the nitrites at 0 ppm. Do 100 % changes if you have to. Let water set in buckets over night everynight (and morning) until you can get the parameters under control.

Salt is definitely a great idea. Mollies typically prefer high pH and hard water so a pH of 6.6 would be cause for alarm.

I have not had methylene blue kill my bacteria. It maybe that your water conditions caused the symptoms.

 

[snazy]

Methylene blue does have some effect against gram positive bacteria which your filter bacteria is so depending on the dosage used it's quite possible it killed some bacs to cause a spike, especially in a tank with higher bioload. The good news is it has positive effect on nitrIte poisoning

 
Here is some more info from a random website:
 
Methylene Blue is effective against skin and gill flukes, ick, velvet, fungus and many external parasites and bacterial infections. This compound is very safe to use even for many invertebrates. Methylene Blue works by staining cells and disabling their metabolism.
A positive side effect of this compound is the ability to increase hemoglobin (oxygen carrying cells) by transforming methemoglobin. Because of this characteristic, methylene blue can be used to treat nitrite and cyanide poisoning.
Methylene Blue should not be used in the main aquarium as it will destroy or severely defect the biological filter bacteria. It can also permanently discolor equipment and silicate seals blue.

 

[TwoTankAmin]

Methylene blue does have some effect against gram positive bacteria which your filter bacteria is

 
 
The autotrophic nitrifying bacteria belong to the phylum Proteobacteria:
 

This large group of bacteria form a clade sharing related rRNA sequences. They are all Gram-negative but come in every shape (rods, cocci, spirilla). They are further subdivided into 5 clades: alpha-, beta-, gamma-, delta-, and epsilon proteobacteria.

From http/users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/Eubacteria.html#proteobacteria
 
The ones in our tanks are the beta (β) proteobacteria.

 

[snazy]

Well, the fact remains that medication that treats gram positive infections normally kills the filter bacteria too. I can't comment from what group it is but medications have effect on it.

 

[TwoTankAmin]

I would greatly appreciate it if you provide any evidence to support what your are stating.
 
I would also suggest you investigate the resistance to antibiotics due to biofilms. The nitrifying bacteria in our tanks live in a biofilm which provides all sorts of protection against hostile conditions, including antibiotics. Research has shown that the older the biofilm, the more resistant it can be.
 

Gram-positive organisms growing as biofilms proved to be particularly resistant to most antimicrobial agents.

From http/www.ncbi.nlm.nih.gov/pmc/articles/PMC226988/
 
This is not to say that no antibiotics in any dose cane cause harm or death to the bacteria in our tanks. But how effective any of them may be is not so simple an issue. If you are interested in research on this typing "biofilms able to inhibit the efficacy of antibiotics" into the Google Scholar search box.
 
Over the years I have treated many tanks with erythromycin.
 

Erythromycin is most effective against gram-positive bacteria such as pneumococci, streptococci, and some staphylococci (see Gram's stain). The antibiotic also has some effect on gram-negative bacteria and some fungi

 
I have never had it wipe out enough bacteria to have any noticeable effect on the tank or fish. It is a great way to beat back bga and I have also used it fir that with good results and not cycling issues.
 
However, the above does not mean that the nitrifying bacteria are invulnerable to antibiotics. Far from it. What it does mean in many instances it may not be an issue but in others it can be. So it is best to monitor for ammonia when medicating to be on the safe side. However, one should not simply assume that any antibiotic used will wipe out ones bacteria.
 
 

 

[snazy]

It also depends on how the antibiotic is formulated. Obviously most manufacturers are striving to make a product that doesn't affect the bio filter too much. Erythromycin for BGA is normally used at half dose, so this is another thing, how much and how long you need to treat. And it does affect some peoples tanks when used so how old and robust your filter bacteria is will also matter. Try using this in a newly cycled tank and tell me it didn't affect the filter.
 
 

However, one should not simply assume that any antibiotic used will wipe out ones bacteria.

 
I think to be on the cautious side, one should assume that any would wipe the bacteria and monitor. If they don't, then great.

 

[byork]

Methylene blue is more commonly used as a pigment than an antibiotic at least in the world of science outside of the aquarium. Additionally there are many well known sources than clearly state that the nitrifying bacteria in biological filters are gram negative. If you would truly like a list of reading material I would be happy to write one if TwoTankAmin has not already provided one. However, I think we MAY all agree that antibiotics that target specific bacteria can cause harm to bacteria outside of that spectrum when administered at high doses.

I guess the water was not tested before the medication was added since the parameters have not been posted?