brown spots in new planted tank
Just planted a tank for the 1st time less than 2 weeks ago. Tall (22") narrow (17") fluval edge 12 gal w/ 42 bright white 7600K high luminosity LEDs. Very bright room w/ wall of windows facing south 4' from tank. No background, just Edge's central column housing heater/filter. Water 80-82' & pH is 7.6 down from 7.8. One betta, 8 rasboras, 1 zebra nerite.
Read plant stickies on this site. Told LFS that I wanted low light, hardy, easy, no CO2 plants. 2x amazon swords, 3x anubias nanas & 3x Vallisneria. Also had a mid-size mystery plant w/ cool cyperus-papyrus like leaves, but shed like crazy & thrown away.
Can anyone tell me what this brown stuff coating leaves of Echinodorus amazonicus (see images)? I've cut off all of the leaves w/ the brown gunk, big spots or just decaying. At this point, have half the leaves I initally did, & plants/aquarium look really, really sparse.
Not sure whether this is standard part of the transition process, or something worse. The first 2x times I did a water change a lot of the plants came up so I had to re-dig them into sand; may have been traumatic.
Can the heater be a problem?
Design questions: can anyone recommend a midsize, hardy, easy, no CO2
plants to go in front of the tall amazonicus/Vallisneria & behind the anubias nanas & something very low, kind of a groundcover?
BTW, bought a long narrow piece of driftwood & wrapped w/ java moss to angle in an S-curve across tank from lower front to higher back, but mis-measured when I cut, & it's to short to wedge as originally planned. Instead it floats...not so good. Going to buy a longer one & start again.