Dealing with Blue Green Algae (BGA)

[wasabi8888]

smallfish...

well.... i am redoing my whole tank.... major rescape.. took the same opp to shift tank to home instead of office...

also, i am going to plant heavily this time. i feel this is the problem above everything else. in my previous scape, i never had this prob before the main differnce was number of plants

[Shiv]

that was an excellent eyeopener from Tom Barr. thanks a lot for your wonderful mail for all of us who are new in plantation and are always dependent on some major issues (like algae control) on aquatic quotient.

[PeterGwee]

Hi Tom

I cant speak for others but i definitely agree that bad plant growth is the basis of algae insurgence. You did mention that in order for good plant growth, there needs to be sufficient nutrients, CO2 and etc.

The issue that I have esp in this BGA attack is not that i dont believe what you say, rather I am unsure what is missing on the tank.

One indication of sufficient nutrients is the growth of the plants. however since i do not know what is missing, i will not dose those nutrients and thus bad plant growth. I have bought test kits (in this case, nitrate test kit which reads 20ppm), but these kits as mentioned in the forum could be inaccurate. So how would i know what i should add? You did mentioned adding NO3, but i dun even know whether i have a surplus in the tank. Presently i keep apistos in the tank and they are rather sensitive to NO3. Do I add blindly then?

That's my opinion of this issue. Of course i want to learn as much as I can. As what benny told me, sometimes it's hard to seek advice over the net cos there are so many parameters and issues that's hidden. In my case, i realised I may not even have enough plants in the first place, and thus BGA could have occured.

I have read many of your posts and know you are a guru and experienced in this field. But it's just that I dun know what to do rather than I dun want to do it.

wasabi8888, the Estimative Index method which Tom came up with is based on test results using lab grade quality test kits. The results were based on an experiment conducted on a heavily planted tank with 5.5wpg of light intensity. The rate of uptake was measured over the course of a couple of weeks and the max uptake rate per day was noted. Estimative index method dosing rate is much higher than the uptake rate such that the plants would never run out of nutrients and stunt. Doing the large 50% water changes weekly takes the test kits out of the equation since the level of buildup would never be more than 2x of what you dosed.

Regarding the test kit issues, you definitely need quality lab grade stuff to have good consistent results and even then they need to be done with referrence to standard solutions. It is almost impossible for very high NO3 to occur in a tank without a heavy amount of NH4 present. (Your critters would have been dead if that is true.). I went over a hobby grade test kit which measured 40ppm of NO3 and then did a large 80% water change. The reading came down to 5ppm but somehow shot up to 40ppm the next day. It cannot be true from the experience I had from work. It really takes alot of NH4 to get a high number of NO3 from bacteria nitrification process and not to say a large amount of DO is needed.

Regards
Peter Gwee

[cwtan12]

i managed to get rid of BGA 3 times so far. all through major water change (80%-100%). then increase CO2 and fertiliser dosage...

[wongteeliang]

Egeria densa - this plant is known to secretes antibiotic substance that helps preventing BGA.. it is a cheap and easily available plant and easy to grow too..

Anyone see it near AMK area. Hope it works for me. Those disgusting stinking bacteria...

[mtanec]

Tom, I understand how you feel..

People, we must understand what is algae before we deal with them.. many suggested solutions are merely temporary solutions.. First, we must understand the type of algae we are dealing with, their nature and what triggers them.. eg, green spot, hair algae and BGA.. all three are algaes but they triggered by different factors and need to be handled differently too..

many suggest add this chemical, add that fish or blackout or scraping, etc.. yes it helps for a while.. but I can ensure you.. you have not remove the root yet!! learn more about the algae then attack what triggers the algae so that type of algae will never come back again..

another thing to consider.. why algae? becuz your water condition is favorable for them to grow.. so doing any other things without altering your water parameters will not help becuz they will come back again and again.. As Tom mentioned, poor plant growth is the main trigger of algae problem..

the art of aquascaping is to balance the chemistry so well that plant growth is at its optimal yet water condition is perfect for fishes/shrimps/snails to live in.. it is all about balancing to create a well balanced ecology in your home.. dun let yourself get distracted from aquascaping into combating algae.. taking them head on without looking at the root will demoralise you.. too often the case, many aquascaper give up the hobby becuz of countless battle lost which incur massive amount of time and money.. looking back at the root problem doesn't take much and you will learn more..

like I mentioned, BGA is not an algae.. using chemical helps but its only a temporary solution.. potentially lead to drug abuse for tank that will affect the eecology cycle.. I already given the solution to solve the root problem.. look at the cause, attack the triggers and adjust what's lacking to achieve a more perfect water condition..

a general rule where many experience aquarium owner will know, take care of the water and the water will take care of whatever is in it.. it is not taking care of what is living in it while ignoring the water or combating invasion head on without removing the source..

What I have stated is just some concepts.. you may not agree to it but I am not saying it is 100% correct.. because there are some people out there who believe in "quick and dirty" method.. they scape just to achieve the desired look without concerning how long it will last.. these people just want things the quick way, plant today and take picture tomorrow to gain credits and tear down the whole thing after a few weeks.. These aquascaping concepts are base on short term goal and they will be the ones who will not agree with my long term solutions.. what I am trying to introduce is more than jus a solution, but a concept that will keep your tank going and last for a long time..

my two cent worth.. no ill intention.. cheers.

[Plantbrain]

Egeria denasa will not cure BGA, this much I can tell you.
It is the main weed in theb Sacramento River Delta here in CA, USA. I've seen it covered with the same species of BGA we have in our tanks, I've seen it covered by the acre!!!

When you read those so called chemical studies or references them, they are often where they taske veryb concentrated extracts of a plant, add it to small test well with the BGA in there(which species of BGA was in the test well? Generally......... not the one that's in our tanks!! That is a very important question!!!) and the extract does not kill the BGa entirely, it might reduce growth by 30% vs a control, not much and not enough to help us.

The other issue that is assumed, and this is a very bad assumption..........crushed up grown plant extract is not the same as live living actively growing plants!!!!!



Keep these issues in mind when ver you folks consider such allelopathic effects on algae, be specifics with the species and look for hard data, then also consider how well the experiment applies to our tank in reality.

We don't grind up our plants, add 5 cups of Egeria juice to our 20 gallon plant tanks to cure BGA.

That is what these experiements general entail...........

As far as NO3 and Apisto's, I have Apisto's!!!
I dose using EI, so do many, they are fine.

When you refer to sensitivety of Apisto's to NO3, this is quite different if the NO3 is derived from Fish waste, dead fish, excess food, excess bioload/fish load, dead/dying plants vs an inorganic source such as KNO3.

See if you can figure out why they would affect the fish very differently.

What does the fish waste start out as?

NH4.

What most often does it end up as in a non planted tank?

NO3.

Which of these two uses up O2 in the filter and is 200-1000X more toxic to sensitive fishes?

Still think KNO3 and NO3 derived from organic sources are similar?

I've gone to over 120ppm with KNO3 with a large population of wild SA fishes.
I exposed them to this for over 3 days.

I did not lose a single fish.
I did lose some Amano shrimp.
The range of the kit only went to 120, but the NO3 level was higher, around 160ppm I'd say.

Other things may have killed the shrimps, buit it's clear that this level of NO3, did not kill the fish. Yes, there are Apisto's in that/this tank.

Using EI without a test kit is not blindly dosing BTW, it's more accurate than most folk's test kits. Even as accurate as Lamotte test kits.

You prevent anything from building up since you do weekly large water changes, not a bad idea for these fish either(any fish for that matter)!!

Need more control and a narrower range for the NO3 dosing?
Do 2x a week 50-70% water changes.

It's that simple.

If the water is 70% new and you how much KNO3 you add, then the make up water is mostly a calibration solution that are used to calibrate a test kit!
Doing this each time you dose, this provides highly accurate results.

But we generally don't need that many water changes and accuracy, so we just estimate and skip a water change mid week etc.

The weekly total KNO3 dosed will never exceed 2x with weekly 50% water changes, so if you added 20ppm a week, you'll never get beyond 40ppm, and that assumes no plant uptake!!

If you change 75% weekly, then the build up will much less, your range will be more like 20-28ppm.

Again, this assumes you have no plant uptake.

Let's add the plant uptake rates in here, say 1-3 ppm per day NO3 and use 50% water changes.

1ppm(lower light, slower growing etc)-3 ppm(higher light, faster growing) x 7 days= 7-21ppm.

So with 20ppm a week added, you'll be at negative -1ppm in a high light tank!!! and thereafter from the first week on..............

With a slower growing tank, you'll be at 20-7 ppm, 13ppm, this will slowly rise to about 25-30ppm or so.

If you increase the water change % or do so once a month, say 75%, this will flush out any such build up if you think it's inherently bad to have these ranges.

But.............folks believe that anything above 10-20ppm is bad due to fish health advice from old references based on NH4/fishwaste/dead fish/too much bioloading etc, not from KNO3.

That is a different situation altogether.

So you can see that there are issues with old advice when applied to dosing and planted tanks.

Just help others learn and not make these same assumptions that are not applicable to our cases.

Note: they are apllicable to fish only tanks. But getting rid of algae in a non planted tank is very easy

Regards,
Tom Barr

[Plantbrain]

i managed to get rid of BGA 3 times so far. all through major water change (80%-100%). then increase CO2 and fertiliser dosage...

I've been able to do this as well.
I'll often do 3 water changes , one each day (50-75%) and clean well, clean the filter, scrub glass, equipment etc.
Then dose after.

The BGA comes back when you neglect the tank.

Regards,
Tom Barr

[freezze]

i manage to get rid of the bga in my tank after a 4-5 day blackout..

presently dose 1teapns of Kno3 every alternate day n 30ml of sera florena on wednesday. 30% water change every fortnightly.. manage to keep the bga at bay for almost 1mth.. but hair algae has appear.

[mikehooi]

hi there,

long time did not post in this forum d,

btw,recently my tank got infected with BGA, 100x50x50 cm tank, bga cover my whole lawn of glosso and hairgrass and riccia. having a sleepless night thinking bout it, keep removing and yet coming back. only last week i got mad, i pour in lot of tetra flora pride, probably around 50 ml.....and miracle happen...the bga start to dissapear in 2days time, i don know the reason but jus to share my experience in killing the bga.

another thing, i did black out before, bga die off but come back in less than a week in my case.

[barmby]

Must do the whole set. clean filter, scrub the tanks, clear the algae, siphon the water 50%, refill the water, power up filter, load kno3 in excess, black out with blankets/newspaper/trash bags and after three days.. another 50% water change, add back the nutrients.