Why do I have BGA at a certain place?
I would like to ask you something that has to do with BGA. In my discus aquarium (which I will describe below) I have a spot of 5 cm length and 0.5 cm width BGA on a particular place on my gravel. This place is between the glass and the gravel. Actually it doesn't bother me cleaning it once every 2 weeks but I was wondering why do I get that spot of BGA at this exact place.
My aquarium is 1.5m length, 50 cm width, 70 cm height. Upon the startup I used Sera floredepot, Aq. Pharmaceuticals Pure Laterite and then 4 cm of neutral gravel. All the plants go very well. The lighting I have is: 2 T5 Arcadia Plant pro 54W each for 12 hours and 1 Osram 54W/865 (54W, 6500 K) for 5-6 hours per day. For filtration I use a sump of 110 lt with 2 Eheim 1260 (2400 lt/h each). The circulation I have is about 3000-3500 lt/h through an overflow tower. I use presurized CO2 with pH controller. For fertilisation I use Seachem Flourish with a liquidoser, and KNO3 for nitrates, K2HPO4 for PO4, Hobby-dose Iron. I keep the nitrates at a level of ~20 ppm, PO4 at ~0.5-1 ppm, Fe at ~0.5 ppm.
I do not have any problems with my plants growing and flowering at all. I have Anubias barteri var. barteri, Anubias barteri var.nana, Anubias heterophylla, Cryptocoryne crispatula var. balansae, Cryptocoryne wendtii "brown", Cryptocoryne wendtii "green", Echinodorus bleheri, Eusteralis stellata (Pogostemon stellata), Ludwigia repens "Rubin", Nymphaea lotus (zenkeri), Sagittaria subulata, Vallisneria americana (natans), Vesicularia dubyana (java moss).
Do you have an idea of why do I have that BGA at this particullary spot? Is it possible that I do not have enough circulation at that place? My NO3s are ok, don't you think?
Eheim Pimp Club #158