Hi, first post here.
I've been cycling a "new" set-up of a 400L (100gal) Jewel Rio 400 aquarium, preparing it for planted Discus aquarium... It's been cycling now for 2 months, but the plants don't seem to be happy; only anubias is growing nicely, echinodorus has transparent brown leaves, camboba is rotting away and dying and valisnerias are just not going anywhere but shrinking and withering.
Here's the situation:
Substrate: Prodac (peat plates) and about 5-7cm of 5mm-1cm granite pebbles (no limestone)
Lights: new Philips Aqua Sky in Aqua Relle (2x36w; 120cm) (before replacement I had standard Juwel lights that come with Rio 400 system)
CO2 system: Ferplast CO2 Energy Professional tank, pump 250l/h (should suffice 500L tanks); set for 1,5 bubbles/s
Filters: internal 1000L/h and external for another 1000L/h
Parameters (stable!): NO2=0,0; NH4=0,0; kH=4; gH=5; pH=7,5 (too basic? should I be adding acidifiers?)
Plants: anubias (nana and another one - bigger, don't know the name), valisnerias, echinodoruses (2 kinds; smaller and bigger ones), cambobas, several cryptocorinas.
So, the aquarium has been cycling for approx. 2 months; parameters stable, but plant growth poor or plants dying (except for anubias). I'm not adding any fertilisers, for I assumed fresh substrate should do the job initially.
Any suggestions what may be wrong? Too little light (even though Rio400 set-up is made for 2 bulbs)? Not enough CO2? Should I start adding fertilisers?
Below are pictures of some of the described "symptoms".
Any suggestion / help would be much appreciated!