# Maracyn dosing and BGA (Cyanobacteria)



## perfectly_circle01 (Jul 24, 2013)

Hello folks,

I am attempting to remedy my recent blue-green algae problems in my 65 gallon tank by either dosing Maracyn or doing a blackout. I'm not sure which might be more effective. I have a couple of questions:

1) I have never used Maracyn before, but read that it can kill off BGA. How much would I need for a 65 gallon tank? Do I need to do anything with my canister filter? I have a an Aquatop CF-500UV.

2) If I were to do a blackout, does anyone have a suggestion on what to use to cover the tank? My tank is in my living room, and is fairly well lit with a large bowed window. I can pull the curtains, but still need a way to cover the tank. I was thinking cardboard, but not sure if there are better ideas.

3) Regarding the bowed window, my tank is about 13' away from it. The window is quite large, about 9' x 5' but I would not consider it "direct sunlight". Could the window be a potential algae issue? I have a Marineland Double Bright LED fixture on the tank, on for 8 hours per day. I currently have about 12 water wisteria plants in the tank, all cut from the original. I plan to add more plants once I get my BGA under control.

I recently purchased powdered potassium nitrate to add to the tank, I think low nitrate is causing my issues. I also added a second airstone, so there is one on each end of the tank.

Thanks in advance for any help.


----------



## hiatus (Jan 25, 2014)

Hi

I don't know about Antibiotics, but I used black trash bags and duck tape. A Blackout isn't easy or fun. I left mine for 6 days and no more BGA.


----------



## dinnese (Feb 4, 2013)

I recently used Maracyn for treating the Cyanobacteria. It was something that had persisted in my tank for weeks until it finally needed to be addressed. Well it's been 2-3 weeks now since I treated the tank and I'm glad to say that it is completely gone. The product works well and my tank suffered no side effects.


----------



## yashmack (May 20, 2013)

expect all the bacteria in your filter to die as well
youre going to need to watch your water parameters and do frequent water changes until your crashed cycle can recover


----------



## perfectly_circle01 (Jul 24, 2013)

I have a bacteria supplement I can add, but I imagine the Maracyn will just kill it off. Any idea of how much Maracyn I need to order to treat my 65 gallon tank? Do I just use regular Maracyn? I see a few varieties of it.

Maybe the black out is the better idea afterall....


----------



## neilshieh (Sep 6, 2010)

ive used maracyn with great results. I didn't follow instructions, dosed at half strength, didnt do a water change until 2 weeks later. Because of this I had a really small mini cycle, nothing serious. when you use it the bga noticeably dies and gets weaker but won't completely disappear at the end of 5 days. it goes away in the following week.


----------



## ua hua (Oct 30, 2009)

yashmack said:


> expect all the bacteria in your filter to die as well
> youre going to need to watch your water parameters and do frequent water changes until your crashed cycle can recover


This is not true. While some bacteria may die off to say that ALL of the bacteria will die and your cycle will start over is simply not the case. If you don't overdose it you will be fine. I don't think people understand just how much bacteria is living in your tank and not only in your filter but in the substrate and on everything in your tank.


----------



## neilshieh (Sep 6, 2010)

ua hua said:


> This is not true. While some bacteria may die off to say that ALL of the bacteria will die and your cycle will start over is simply not the case. If you don't overdose it you will be fine. I don't think people understand just how much bacteria is living in your tank and not only in your filter but in the substrate and on everything in your tank.


agreed, from what i saw assuming your tank is appropriately filtered even if some bacteria dies off it's not going to be that big of a problem. At most it'll cause a mini cycle but it won't cause your bio filter to crash. most people report it not having an effect at all.


----------



## yashmack (May 20, 2013)

ua hua said:


> This is not true. While some bacteria may die off to say that ALL of the bacteria will die and your cycle will start over is simply not the case. If you don't overdose it you will be fine. I don't think people understand just how much bacteria is living in your tank and not only in your filter but in the substrate and on everything in your tank.


I didnt say it will, i said to expect it to kill it all and be ready to do water changes. its not guaranteed but its possible. it will affect the cycle though as it IS an antibacterial medication, and your filter is chock full of bacteria. Nitrifying bacteria is what populates your filter and eats fish waste.
Be ready for a cash...


----------



## dzega (Apr 22, 2013)

erythormicin is the safest way to go treating BGA. at recommended does it does not kill benefit bacteria. black out will run you in more trouble for sure since your weakened plants die off at that point producing waste.
the reason this antibiotic does not kill your filter bacteria is it reacts only with curtain type of bacteria and luckily filter bacteria is not that type


----------



## neilshieh (Sep 6, 2010)

dzega said:


> erythormicin is the safest way to go treating BGA. at recommended does it does not kill benefit bacteria. black out will run you in more trouble for sure since your weakened plants die off at that point producing waste.
> the reason this antibiotic does not kill your filter bacteria is it reacts only with curtain type of bacteria and luckily filter bacteria is not that type


not necessarily true. Plants will not die from a blackout because they have energy reserves that algae don't (except for clado). If a blackout were really that harmful then we'd never be able to ship plants :icon_lol:

imo i've only done 3 day blackouts and it works fine. The plants get a little elongated and the reds less red but that's expected.


----------



## OVT (Nov 29, 2011)

neilshieh said:


> Plants have energy reserves that algae don't (except for clado).


And where does this info come from?

Pretty easy to try out: ship a box of plants with algae across the USA.

On the OP's subject: one packet per 10g of aquarium water (detailed instructions on the box). It kills BGA, does not kill your fish or your nitrifying bacteria.

v3


----------



## neilshieh (Sep 6, 2010)

OVT said:


> And where does this info come from?
> 
> Pretty easy to try out: ship a box of plants with algae across the USA.
> 
> ...



youre right. unsubstantiated. i read that somewhere for green water so i assumed it was the same logic for all algaes that we use blackouts to deal with. doesnt apply to bba or staghorn or clado to name a few.


Sent from my iPhone using Tapatalk


----------

