EI results in BGA; is my macro solution correct?

[Gilles]

My container is currently 1000.0mL; i add into 1 mix:
- 57g KNO3
- 7g KH2PO4
- 83g K2SO4
- 169g MgSO

And i dose 240.0 mL /week (spread across 3 dosages of 80mL) into a 400.0L tank. This gives:
- NO3: 21ppm/week
- PO4: 2.9ppm/wek
- K: 22.3ppm/week
- Mg: 10ppm/week

If i enter these values at Wet's EI calculator it seems that the only element that is to low is K, based on the article by @ceg4048 ; but i do get BGA; it only happens on about a 10cm wide spot area at the front glass (with patches BGA of 1cm) and current is present on that place (spraybar across the length of the tank) so it can't be a deadspot. Substrate is akadama by the way.

I add about 0.4ppm Fe/week; but my Helferi is showing white tips, which could indicate either calcium or Fe shortage, right?

CO2 is added on 2 places on either end of the tank, and drop checker with fresh fluid shows bright yellow.

All help is welcome.. Maybe drop the PO4 in the solution to about 1.5 to 2ppm/week?

 

[Michael W]

Hi,

As far as I am aware It is likely due to poor CO2 levels coupled with high lights or decaying organic matter, but I believe the former is probably the case. I have received plants from a hi-tech tank before with some BBA and once it's in my shrimp tank which is a low tech with lights on for 5 hours a day, the BBA slowly but surely disappeared. I will contribute that to not having CO2 problems due to low light/photo period with adequate flow and not to do with ferts. I had not made any physical attempts to remove the BBA because the plants were costly and I was scared of damage.

 

[sciencefiction]

I've moved plants covered in BBA from one low tech to another that never had BBA and the algae died too, but it doesn't mean it had anything to do with co2 levels in those tanks as both get none besides what there is naturally.

But I think Gillies is talking about Blue Green Algae

but my Helferi is showing white tips, which could indicate either calcium or Fe shortage,

No, white tips is not a Fe shortage. The entire new growth goes pale, old leaves are fine unless you have a Fe shortage for months on an off.
Blue Green algae can be caused by low nitrates, dead zone, lack of flow/distribution in the area where BGA grows.

 

[Michael W]

I've moved plants covered in BBA from one low tech to another that never had BBA and the algae died too, but it doesn't mean it had anything to do with co2 levels in those tanks as both get none besides what there is naturally.

I think its due to the lack of CO2 addition making its level fluctuating less than that of a high tech tank without good flow/ or high lighting levels. But I could be wrong.

 

[sciencefiction]

I think its due to the lack of CO2 addition making its level fluctuating less than that of a high tech tank without good flow/ or high lighting levels. But I could be wrong.

Well, both are low tech, only one ever had BBA in which I had reduced the light to minimum without any success whatsoever. The CO2 fluctuates as much as in the other tank as far as any additions go, which is 50% water changes weekly. The tank with BBA is overstocked so my guess is organics is the major cause of BBA.

 

[Michael W]

The tank with BBA is overstocked so my guess is organics is the major cause of BBA.

That is very likely, I usually hear the case of BBA growing on driftwood or plants tied on them.

 

[sciencefiction]

That is very likely, I usually hear the case of BBA growing on driftwood or plants tied on them.

Yeah, it loves driftwood, because possibly the driftwood is realeasing/storing organics. It loves powerheads, filter outlets, basically all areas that literally get "dirty" more easily. And it loves damaged plant leaves, which again are releasing organics. Sometimes the damage of the leaves/plants is still not visible so "healthy" looking plants get attacked but they aren't healthy if they are getting BBA.

And the reason for high organics in the tank can be different. It could be because of overstocking with fish or because the plants are suffering for one or another reason, and that's where CO2 comes in place as a cause, the lack of it causing damage to the plants, which in turn causes organics release, and in turn BBA.

 

[ceg4048]

but i do get BGA; it only happens on about a 10cm wide spot area at the front glass (with patches BGA of 1cm)

First of all, it's very inaccurate to state that EI resulted in BGA.

Many tanks which are NOT being dosed EI suffer BGA, while concurrently many tanks being dosed with EI do not suffer BGA, so BGA cannot possibly be a result solely due to EI.
It would be much more accurate to state that Gilles results in BGA.

BGA is fundamentally a symptom of poor NO3 uptake.

So what's needed is to remember that fundamental cause and to then try and understand what conditions are resulting in poor NO3.
If the dosing is correct, which appears likely, then one has to then go down the list of ways the tank could fail to deliver that concentration. The most likely way is due to poor flow/distribution, so it would be a matter of finding a way to improve flow to that area.

Another possibility is that of excessive lighting which should always be a suspect.

BGA can also be triggered by poor filter maintenance or from ammonia pulses of (combined with low oxygen) leaching from the substrate so it might be worth investigating possible ammonia sources in the substrate such as decaying organic matter or ammonia based fertilizers. Repeated vacuuming of the substrate is a good idea to remove detritus.

Far from reducing the nutrient loading, which is always a terrible idea within this context, It's often a good idea to double the NO3 content to temporarily increase the concentration. If this work in reducing the BGA then its a certainty that flow/distribution needs to be improved.

It's also possible that I'm in an alternate universe because everyone else is talking about BBA, which has nothing to do with BGA.

Cheers,

 

[sciencefiction]

It's also possible that I'm in an alternate universe because everyone else is talking about BBA, which has nothing to do with BGA.

Ha, ha, no, we got that part, we just got locked into another topic for a few minutes. Apologies

 

[Michael W]

I just noticed this... BGA... I am also sorry.... I totally misread that is unbelievable. I didn't realise the OP said BGA I was wondering at one point where SF was going with blue green algae having thought it was BBA.

 

[Gilles]

yes, Blue Green Algae, not black brush algae
i don't have BBA anymore since i fixed my CO2 issues

If the dosing is correct, which appears likely, then one has to then go down the list of ways the tank could fail to deliver that concentration. The most likely way is due to poor flow/distribution, so it would be a matter of finding a way to improve flow to that area.

Flow cannot be the issue here; the spraybar is across the entire tank length; pointing towards the front glass, holes are drilled based on the output of the filter and the Eichinodorus Tenellus 'Green' which is also at the front glass is slowly 'waving' in the current; which if i recall correctly from another "flow" thread is a good sign.

Another possibility is that of excessive lighting which should always be a suspect.

True, but i measured this with a PAR meter from Apogee and it is about 60 uMol at the spot.

BGA can also be triggered by poor filter maintenance or from ammonia pulses of (combined with low oxygen) leaching from the substrate so it might be worth investigating possible ammonia sources in the substrate such as decaying organic matter or ammonia based fertilizers. Repeated vacuuming of the substrate is a good idea to remove detritus.

I recently (3 weeks ago) cleaned my filter; which still has the basic Fluval FX6 contents; after adjusting my CO2 some of my Amano shrimp died and i removed them immediately. No shrimp died in that location btw.

Far from reducing the nutrient loading, which is always a terrible idea within this context, It's often a good idea to double the NO3 content to temporarily increase the concentration. If this work in reducing the BGA then its a certainty that flow/distribution needs to be improved.

Check, will double the NO3 contents in my solution.

What about the contents of my filter; you mentioned some time ago that pot filters for planted tanks can be near empty; maybe i can improve on this part too, and end up getting more flow;