Support for exhausted substrate
Dear Tech Support,
My current fish tank (50x22x22in - approx 320l/84gal) has been set up for 5 year. I believe the minerals/fertilizer that was originally in the substrate should have been exhausted by tge end of the 2nd year. Since then I had been inserting Flourish tabs into the gravel at the rate of 10 tabs every 3 months. Besides this, I dose with Flourish at the rate of 1.5ml at each weekly 25% water change and 1ml every alternate day thereafter. Flourish Excel is dosed at 8ml daily and Flourish Iron is dosed 1ml twice a week. I have CO2 dosing at 1 bubble every 2 seconds and my lighting is 2x36W with full reflector for 11 hours. My water parameters are:
ph 6.7 - 7.1
KH 2 - 3 dH
GH 2 - 3 dH
Nitrate 5 - 10 mg/l
Phosphate <5 mg/l or not detectable.
The tank is filled a 10 octos, 15 shrimps, 5 corys, 2 SAE and about 30 to 50 varying size of guppys at any time. The fishes are feed 3 times per day with most food consumed within 2 to 3 minutes.
My plants consist of Crypts, Hydrophila difformis, Ceratopteris thalictroides and Anubias barteri var. nana. The plants are flourishing with minimal algae. Do you think the current fertilization of the substrate with Flourish tabs is adequate.