# blue green algae (BGA) - potassium nitrate



## bigfish

hi, 

i've done a lot of reading on fixing BGA problem and the consensus seems to be a need for nitrate. I just want to confirm, is this potassium nitrate? do i just pick it up from a gardening store? and what is the dosing scheme? if you have some of this stuff you can sell me please let me know as well!!


here's the background on my tank, thanks

typical 10g tank

lighting - hood with 2 bulbs - 2x 26w 6500K spiral bulbs - about 10 hours a day with 2 hours off in between. water is filled right to the top, so the light hovers a few cm above the water line. also used some aluminium foil to cover the areas behidn the bulbs for added relfectiveness

substrate - half inch min. topsoil with no additives, a few cm of regular gravel over top

water - my house uses water softener

plants - a few bunched of hornwort, few stems of cabomba, a few bunches of bacopa australis

fish - a dozen guppies, about 3 adults and the rest are frys or older (also 2 pond snails)

filter - HOB aquaclear (with the 3 layers of filter mediums). doesn't hang in the middle, it is off to one side.

co2 - diy, just added the past weekend fed into the filter intake, 1.5 bubble per sec

temp - about 80F


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## coldmantis

pm me if you need macro nutrients which contain potassium nitrate.


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## Darkblade48

bigfish said:


> hi,
> 
> i've done a lot of reading on fixing BGA problem and the consensus seems to be a need for nitrate. I just want to confirm, is this potassium nitrate? do i just pick it up from a gardening store? and what is the dosing scheme? if you have some of this stuff you can sell me please let me know as well!!


The easiest way to add a source of nitrogen to the aquarium is to add it as nitrate. In most cases, the easiest way is to add it as potassium nitrate as you are also adding some potassium (which is required by plants) at the same time.

Of course, you can also use other nitrate salts (calcium nitrate jumps to my mind).

You will not likely be able to pick up pure potassium nitrate from the gardening store, but most hydroponic stores will carry it.

As for the dosing scheme, please take a look at my planted guide (linked in my signature) for an outline of the various dosing regimens that are available.

As you have high light, I would definitely recommend the EI dosing regimen.



bigfish said:


> water - my house uses water softener


See if you can bypass the water softener when you are doing water changes. Most water softeners use sodium chloride to remove the cations in the water (unless you are buying the more expensive potassium chloride). The addition of sodium cations into the water column is undesirable.


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## arinsi

all you need is maracyn
which contains erythromycin
make sure you get maracyn 1 and not the others
i bought mine at big als but thats probably not the only place you can get it










i had a serious case of bga back when i first started and i think i dosed a packet each day
problem solved in a few weeks

just read up on bga and maracyn


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## Darkblade48

Erythromycin can kill off cyanobacteria quickly, but without addressing the problem that is causing the BGA, it may come back.


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## bigfish

Thanks guys

Maybe I should just buy the macro nutrients from coldmantis that contains kno3
So what would you say is the root cause of this issue is? What do I need to do to prevent bga from coming back? Thanks


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## BillD

I'm interested in where the idea that BGA occurs in low nitrate conditions. I just wiped out a batch of the red form (with Maracyn). The tank isn't planted so I don't know where the nitrate would go. In the past it has typically occurred, for me, in non planted tanks, although not exclusively.


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## Darkblade48

BillD said:


> I'm interested in where the idea that BGA occurs in low nitrate conditions. I just wiped out a batch of the red form (with Maracyn). The tank isn't planted so I don't know where the nitrate would go. In the past it has typically occurred, for me, in non planted tanks, although not exclusively.


It is interesting to note that BGA can also occur in poorly aerated/low flow areas of the aquarium as well.

Of course, having low nitrates is not necessarily a cause either. To be accurate, I am sure people have noticed a *correlation* of low nitrates leading to BGA.


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## coldmantis

Darkblade48 said:


> It is interesting to note that BGA can also occur in poorly aerated/low flow areas of the aquarium as well.
> 
> Of course, having low nitrates is not necessarily a cause either. To be accurate, I am sure people have noticed a *correlation* of low nitrates leading to BGA.


this is also true, I recently got a little of bga in one of my tanks that I dose everyday, it's very little and didn't spread but I tested the nitrates and it was around the 80ppm. flow should be ok in there, has a 2213 when a diy spray bar that extents to the length of the tank(20g long) and I drilled the holes 3" apart so it shoots out a powerful stream. It was probably due to bad water quality since I don't change water often and excess nutrients because I have dirt in the tank also. lightly stocked tough, 2 sae, 2 otos, 1 small zebra loach and 4 amanos.


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## Darkblade48

coldmantis said:


> this is also true, I recently got a little of bga in one of my tanks that I dose everyday, it's very little and didn't spread but I tested the *nitrates *and it was around the *80ppm*.


Are you sure your nitrates reading are correct? That is very high.


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## coldmantis

Darkblade48 said:


> Are you sure your nitrates reading are correct? That is very high.


I'm 100% sure I am, I know why I have a high nitrate level. you should see my main tank a few months back it was over 100ppm for many months until I change my bulbs because they were closing in on a year and the plants weren't growing fast enough to consume the fertz, after I changed all my bulbs on my main tank all the red plants turned red and nitrates went down to around 20-40ppm but so came the algae because my tank was unbalanced because I stopped dosing kno3 due to my nitrates being so high already.


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## bigfish

I got a hold of some kno3 and also a water pump that does 80gph. Is that flow rate enough?

Thanks


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## Darkblade48

bigfish said:


> I got a hold of some kno3 and also a water pump that does 80gph. Is that flow rate enough?
> 
> Thanks


Seems a bit high, but flow rates are usually overly optimistic on the part of the manufacturer.

Give it a shot, and make sure to remove as much BGA as you can manually first.


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## bigfish

took an hour cleaning out the bga yesterday, but this late afternoon it has already returned. 

this may be my final step before i might give up and put an end to this... added the pump, added 20ppm nitrate last night, and has now sealed it up to black out for the next few days... will see what happens


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## coldmantis

blacking out won't solve the problem and will not get all the bga out in my experience if you want a quicker more effective way of a "quick fix" go to walmart and buy some Hydrogen Peroxide and squirt it on the bga it will die instantly. I use no more then 3ml per gallon, if you have sensitive fish, shrimp do like 1ml-2ml per gallon, if you have vals or riccia don't do it because the H202 will kill those plants.


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## bigfish

would that be found in the pharmacy section?

i left my weekend home which is where my tank is, so won't get to see it till next weekend :S i guess H202 will be my next step if that bloody stuff dont die
we shall see what happens!



coldmantis said:


> blacking out won't solve the problem and will not get all the bga out in my experience if you want a quicker more effective way of a "quick fix" go to walmart and buy some Hydrogen Peroxide and squirt it on the bga it will die instantly. I use no more then 3ml per gallon, if you have sensitive fish, shrimp do like 1ml-2ml per gallon, if you have vals or riccia don't do it because the H202 will kill those plants.


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## coldmantis

yes pharmacy section, any place doesn't have to be walmart will have it, I think I saw a small bottle at dollarama once.


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## bigfish

Cool

Actually, would that be feasible in my case? The bga isn't just a spot... It's pretty much a blanket over the gravel and also all over the leaves of my plants... I'd end up dosing a lot of that stuff wouldn't I?


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## coldmantis

do like 1-3ml per gallon(turn off filter and lights) then like an hour or two later change 40-50% of the water and repeat the next day, should be all gone in less then 3-4 days. my 7.5g cube was blanketed with this stuff and it was gone in like 2 days and never came back I was doing daily fertz after though so it won't come back. I got it from doing an emerse growth of hc cuba(never again!).


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## Darkblade48

Unfortunately, your aquarium is not really maintainable in its current condition.

You cannot just dose once over the weekend, and then leave it alone and expect everything to right itself...


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## bigfish

i got help to dose nitrate, scheduled for today and weds
would that be enough? thx


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## Darkblade48

bigfish said:


> i got help to dose nitrate, scheduled for today and weds
> would that be enough? thx


Hopefully, yes.

Remember, EI was meant to be dosed on a regular basis, not as a once per week thing.

If you cannot have a regular dosing regimen, I would look into automatic dosers, or the like.


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## bigfish

hi

just giving an update
so i've had a complete black out for 5 days, and dosed 3 times kno3 in this period. when i unveiled my tank just now, i could not find a single trace of bga. i think the bba has also disappeared.

plants are doing much better than i expected, although obviously not doing great

i fed the fish, and proceeded with a 50% water change and also dosed 20ppm of kno3. now based on the background info i provided at the top of the thread, can someone please advise what i should do differently from before to prevent the bga from coming back?

were my lights too strong? does my aquaclear HOB not provide enough circulation? 

thanks for all the input!


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## bigfish

Just want to report back for anyone who may run into the same problem as me

It appears that poor circulation was the problem. I installed a pump about 2 weeks ago and now I see no more traces of bga

Thx again to all those that helped out!


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