Salutations, PT community! First post here, so take it easy on me, eh?
I have an 80 gallon tank that I could use some advice on. I've had this tank for about 4 and a half years, just recently started getting into live plants (less than a year). Here's the specs:
80G (4ft long, 18" deep, 24" high I believe)
Small gravel, Fluval plant stratum (I think? not entirely sure)
Fluval 405 external canister
Filter Media (From bottom to top):
Pillow stuffing, Fluval Pre-filter, Fluval Biofoam, Fluval Biomax
Not entirely sure, came with tank. Set to around 75 degrees
24" 17wattT8 fixture, 30" T5 Fixture (18watt colormax/18watt bulb), 17" LED light (400 lumens), 6" 10watt 50/50 mini compact fluorescent bulb
3-4 bunches of Anubias, 2 amazon sword, hornwort
3 adult Red Belly Piranha (about 8" each), Large plecko
10-20% water changes every 2 weeks, clean filter sponges of dirt and plant debris every month, dose with Excel every week, lights on for 6-8 hrs per day
I'm currently away from my house while on break from school, so I can't give you a proper water analysis...
This is my basic setup. No recent problems with algae or snails. Fish seem content, I usually feed them raw chicken or feeder goldfish every week.
My biggest concern is plant growth. The anubias plants seem to grow moderately well, but not fantastic. Some bunches barely show any growth. Sword plant is surviving, but not growing. Haven't seen new growth for a month or so now. Hornwort is floating, seems to grow with no problems. Piranhas like to use it as cover during daylight. I've considered getting a CO2 injection system, but it's very expensive, and I'm a poor college student. DIY CO2 was experimented with, but produced no visible benefits.
Can you ladies and gentlemen recommend any changes to my routine/equipment in order to facilitate better growth? I think CO2 is my biggest issue here, but I'd like some input from more experienced fishkeepers.