BGA attack!

[taz_boy]

my tank has been plagued with BGA attack recently.

before rescaping..already got numerous BGA attacks...all "kinda" solved by using blackout.

After rescaping, i thought BGA wont attack anymore, but recently it attacked again.

condition of tank now: foreground plants infested with BGA and gravel coated with BGA (wasn't that bad last time)

tank parameter:

tank size: 3x 1.5ft x 1.5ft ~ 142litres of water

lighting: 4 x 36W PL, lighting period ~ 6hrs

Co2: 3-5bps (Co2 on concurrently with lights)

water change regime = 20% / week

fert dosing: Lushgro Aqua. 20ml/week ~ 8.9ppm of No3
~ 14.6 ppm of K
Lushgro Micro ~ 1ml/ wk = 0.15ppm of Fe

What are the other problems or factors that cause BGA to keep revisiting?

i've reduced my bio-load, reduce feeding, reposition my spray bar to optimise co2 distribution..

please advice!

[torque6]

i had a tough time with bga, same deal. they are relentless, i have found that blackout dont kill them. I have done a thread with extensive research dealing with them, you may want to check it out before deciding whats the best course of action.

Therotically, they dont appear if your nitrates level are good, seeing you with some nitrate dosing per week, im confirming that these algae will still appear regardless of nitrate levels.

[Shadow]

Lushgro Aqua. 20ml/week in 142 litres of water will give you:

1.0111 ppm of Nitrogen
4.4778 ppm of Nitrate
7.2832 ppm of Potasium
etc-etc based on fertfriend

I don't think ~5.5 of N per weeks is enough. The daily target is 5~30 ppm a day, you are way below target

[blue33]

What filter are you using? Any pics of your tank?

[barmby]

Problem now is Singapore has no shop selling KNO3

[taz_boy]

Lushgro Aqua. 20ml/week in 142 litres of water will give you:

1.0111 ppm of Nitrogen
4.4778 ppm of Nitrate
7.2832 ppm of Potasium
etc-etc based on fertfriend

I don't think ~5.5 of N per weeks is enough. The daily target is 5~30 ppm a day, you are way below target

is N important? because i remember No3 that is the problematic one?

and is it 5-30ppm per week or 5-30ppm/day?

if i dose 20mn/day. it will give me 31.5ppm/week. and i do 20% water change per week. is it ok?

[blue33]

is N important? because i remember No3 that is the problematic one?

and is it 5-30ppm per week or 5-30ppm/day?

if i dose 20mn/day. it will give me 31.5ppm/week. and i do 20% water change per week. is it ok?

no3 problematic is in the past, people has mistaken that and now people realised the important of it. I always dose more than the required till my test kits show over dose, unless you want your red plant turn red if not then you got to dose no3. Your problem may caused due to your circulation and co2. Like we dose using EI method, and EI method is to dose more than enough. no3 can always replace by Seachem Nitrogen if you cant find KNO3.

[taz_boy]

i see. so target ppm is 5-30ppm per week right?

i think i'll triple my dosing per week. will post more pics of my tank later to show the condition of my tank.

[uklau]

Co2: 3-5bps (Co2 on concurrently with lights)

Unless your CO2 is very responsive, it is better to have CO2 turned on 1 hour before the photoperiod.

It's easy to mentioned that BBA is due to CO2 level & distribution but in actual fact, it's not as easy as said to achieve (at least for me). This is true especially for tank that is huge & is densely planted.

[Shadow]

i see. so target ppm is 5-30ppm per week right?

Depend on how you see it, 30ppm per week or 5ppm per day . According to Tom Barr, typical NO3 uptake rate for 24 hours is 1-4ppm. More plant will require more NO3.

NO3 is important but NH4 is problematic, NH4 will cause algae

[barmby]

There is no single reason that contribute to BGA. Too much fishy waste in water. Too much PO4 with too little NO3. Too little CO2.

The short term solution to BGA from Tom Barr:

Fully cover the tank(trash bags, say 2-3 deep of the black tash bags work well)

Clean prior and after, 50% water change on pre and post blackout, clean filter, lightly vacuum the surface to remove any detritus on the surface of the gravel, scrape below the gravel line if any algae is along the glass=gravel
line.

Add KNO3, at 1/4 teaspoon per 20 gal of tank pre and post treatment and then at least 1-2x a week thereafter.

This should address it

[barmby]

From Tom Barr taken from his post a few years ago:

Spraybars are preferred.

Some surface movement(helps with exchange of gas to some degree-too little is bad, too much is bad, also allows better cooling=> more evaporation).

But beyond this, good current below the water's surface is good.

Things will pearl less with increased current, so you can strike a balance there.

[PeterGwee]

BBA is always a CO2 issue with respective to the amount of light given (Limiting). Tom did measurements using a CO2 meter and found the concentrations in plant beds to be around 6-12ppm only. That is the real issue...current and mixing of CO2.

Regards,
Peter Gwee

[blue33]

I usually get a powerhead to drive the current flow in the plant bed to assist nutrient distribute around even though i've a external canister depending on the water circulation. I do discovered lighting is another issue with BBA. In the past and even now(even the LFS) still alot of people said you must have gentle flow in planting which is not really true, at minimum you at least must see your plant have some light movement inorder for the water to bring nutrients to plant membrane.

Also when i dose NPK, i dont dose micro, macro and iron, it has a tendency to react with phosphate.

I tried to achieve(approximately dont have to be accurate),
Nitrate(NO3) 20ppm per week
Potassium(K) 30ppm per week
Phosphate(PO4) 3ppm per week
Magnesium(Mg) 10ppm per week
Iron(FE) 0.5ppm per week

Depending on the plant mass, appearance and intake, dose accordingly to their needs.

[taz_boy]

thanks all for the responses..i'll try to see what's the root of problem to my tank.

i got a feeling is overdosage of PO4 with under dosage of Nitrate.

i think my co2 should be ok. i crank up quite high. though i long time never go measure using my test kit.

quite busy these days. will do a major tank maintaince to clear the BGA in the next couple of days...

do keep suggestions and discussions coming in. thanks in advance!

[taz_boy]

Also when i dose NPK, i dont dose micro, macro and iron, it has a tendency to react with phosphate.

I tried to achieve(approximately dont have to be accurate),
Nitrate(NO3) 20ppm per week
Potassium(K) 30ppm per week
Phosphate(PO4) 3ppm per week
Magnesium(Mg) 10ppm per week
Iron(FE) 0.5ppm per week

Depending on the plant mass, appearance and intake, dose accordingly to their needs.

can i ask what fertiliser you using to dose your targetted amount? i calculated. if i want to achieve 20ppm/wk...my 500ml of Lushgro will finish in 1.5mths.

[barmby]

That is the problem. Singapore has no KNO3. Authorities might as well ban paraffin for obvious reason

[taz_boy]

ya..i still left a bit of my solid kno3 bought long time ago..

i guess the solution no3 is going to burn a hole in my pocket

[blue33]

can i ask what fertiliser you using to dose your targetted amount? i calculated. if i want to achieve 20ppm/wk...my 500ml of Lushgro will finish in 1.5mths.

I'm dosing Lushgro micro/macro 2 times a week for my 13g tank using 2ml/micro per dosage(so my 500ml will last me for a long period) and 5 drops of macro, also got myself prepare NPK dry ferts 3 times a week mix with 600ml water for 12 dosage, dry ferts comes with KNO3, KH2PO4 and MGSO4(i find this to be very important). The plant is growing crazy ever since i'm using this method. You can get those NPK ferts with liquid form i guess, is just that they're pretty diluted.

[r4211z]

lucky me, i still have one big tub of solid KNo3.
But it seems like even current is well distributed, the BBA still can grow, mine was grown on the spray bar as well.
Also Java ferns and fissidens tends to get it more easily ( in my case)

If CO2 reactiveness, my ferns can even bubble.
Hnece Java ferns and Spiky moss is growing like mad, and narrow java ferns as well.

Anyone wants some free FOC plants.....????