Which fertilizers are suitable in case of diminished plant growth?
I already have a CO2 system but now urgently need to fertilize the plants since their growth diminishes considerably and the leaves get holes. Which fertilizer can I use without supporting the growth of brush algae?
if it is really caused by lacking minerals, sera florena (liquid) is recommended for stem plants, sera florenette (tablets) for plants with strong roots such as Echinodorus species. sera floreplus is additionally suitable in both cases.
Considering the additional information (CO2 fertilization / diminishing plant growth) it is, however, also possible, that there is too little nitrogen available (→ nitrate test). You can improve this situation by targeted and moderate (!) addition of nitrate. Nitrate levels about 10 mg/l are desirable - too low nitrate levels, especially in combination with measurable phosphate, often lead to increased brush algae growth!
Dr. Bodo Schnell