Cannot get rid of BBA...

[Andrea67]

Hi Tom!

It's me again with my never-ending BBA issues... We chatted in the APC forum and Aquaplanta too.
I still have problems with BBA.
Tank features:

100 lt.
4 x 18 W fluorescent T8 bulbs (6500 °K) - light duration: 9 hours
KH 4 - GH 6 to 8 - PH 6,4/6,6 - NO3 10/15 mg/lt - PO4 0,5 mg/lt
50% weekly water change tap water + RO water + Equilibrium
CO2 never less than 30 mg/lt during lights on - solenoid driven since 2 weeks
Substrate: 80% flourite 20% plain gravel
Fertilization: 2 x week KNO3 to reach above targets - 1 X week 0,5 ml enema fleet - 3 x week 2 ml Flourish + 1 ml Flourish iron
Plants: echinodorus tenellus, hemianthus micrantemoides, ammania senegalensis, heteranthera zosterifolia, alternatera lilacinia.
Fish: 5/6 otocinclus - 5/6 caridina - 15 neon (very lightly fed)
Nice plants grow and very rich pearling too

I really try to stick to the routine with maximum efforts but I don' understand why the hell I have the BBAstards... (I also have some green algae on glass that I have to clean each 15 days ). After last time we chatted I tried the following to see any change:
1- get the CO2 injection driven by solenoid (shut on 2 hours before lights on - shut off together with lights). I noticed a decrease in PH during light period because (of course) I increased the nr. of bubbles.
2- Dose PO4 once per week instead of two

Results: apparently nothing changed

The next try I'm about to do is to increase total lights period to 10/11 hours but only 5/6 of which with 100% power and the rest at 50% (I can drive the 4 tubes separately). What do you think? Could it be helpful or just a waste... The aim would be to slow down a little bit the growth rate (which wouldn't be bad... I have to prune so often...) and, if there is any limiting nutrient, to keep nutrients available for plants somewhat longer.
Another try I'm thinking about (even if it wouldn't eliminate the problem from its causes) is to use massive dosing of Flourish Excel as algae-killer for BBA (I read it works quite well in burning BBA))
What would you do at my place? Please help because I'm quite disappointed.

Thanks for support
Andrea

 

[Tom Barr]

Re: Cannot get rid of BBA...

Add more CO2, I don't care what your test kits say.
Add more, if the fish act sick and are near the surfacwe, then turn the CO2 down.

Realize since you now have the solenoid, you can add a lot of CO2 when you need, during the day and the CO2 can offgas at night.

This high CO2 for a few hours is less traumatic for animals since the CO2 level is not chronic 24/7.

So you should be able to add plenty.

This will be a visual adjustment to add enough CO2.
Add a little bit more, then see how things go, then add more if the BBA still grows.

BBA is always related to CO2 in every case I've ever looked at.
You can improve the CO2 and not have it go away, but it will not grow once the CO2 is in good shape.

I'd add:
1/4 teaspoon of KNO3
1/16" of KH2PO4

off day add 5mls of traces.

50-70% weekly water change

10 hours of light

You have faster growing stem plants, there is no reason why you cannot trim off the BBA and have fast growth and in 2-3 weeks have a totally BBA free tank with newer growth.

If you want to slow down the growth rates, lower the lighting to 2 tubes or maybe 3 for 2-5 hours.

Regards,
Tom Barr