Hey folks. I don't know if I smell funny and no one wants to talk to me, but I can't seem to get any response over at Planted Tank. Maybe no one knows the answer. I'm hoping someone here will be willing to help me out.
I went out of town Fri-Mon. When I left, my tank looked perfect. Everything was growing nicely, and all plants were deep green. While I was away, I asked my son to dose the tank and left him instructions. He's very responsible, so I know he dosed correctly. When I returned Monday morning, the dwarf hairgrass in the center of my tank was brown and some of the other hairgrass around the corners and front of the tank didn't look as vibrant. The very edges of the entire crypt leaves have now turned brown. The tips of the anubias nana 'petite' are yellowing slightly. I was shocked that things could go south so quickly. I was only gone four days.
About a week before I left, I added CO2. Everything seemed to be doing great with the CO2. The only thing different I did the day before leaving was install a ceramic disk nano diffuser that finally arrived. Before that, I was getting by with a piece of bamboo as an emergency diffuser. The nano ceramic disc may diffuse slightly more CO2 into the water, but I am still running it at the same 1 BPS.
Here is the tank before I left:
Here is the tank when I returned. The dead spot in the center is much worse than it appears here when viewed from above.
I have a theory about what happened. Please let me know your thoughts. I did a water change just before leaving to reset the fertz in the water. When I did the water change, I turned down the filter flow to low to create less disturbance as the water level fell during the water change. I forgot to turn the flow back up after refilling the tank. Do you think the lack of flow could have caused the die-off? Could it also be that the fertz that were added were concentrated toward the center, and with very little flow, they covered that area and burned the grass?
Here is everything I can think of to tell you:
Tank 6.6 Gallons (Petco bookshelf)
Light: 1 T8 (medium to medium-high light in center due to shallow tank and substrate height). On 8 hrs per day with a mid-day siesta of a few hours
Fertilization: NPK even days, Flourish odd days, Osmocote under substrate, Flourish Excel 2.5mL daily until CO2 added (cutting back now)
CO2: Pressurized, 1 BPS, on before lights-on, off before lights-off.
Water Params: Ammonia: 0 to .25 PPM, Nitrite: 0 PPM, Nitrate: 20 PPM, pH 6.6 while CO2 on, GH 30, KH 40, source is good quality well water
Substrate: Seachem Flourite supplemented with Osmocote underneath
No fauna (tank just completed cycle -- will add some algae control soon)
Normally have mild surface agitation from HOB filter flow. This was greatly reduced while away due to lowering flow rate.
I also have some anubias nana 'petite' that appear to be yellowing at the tips.
Crypts are developing a thin brown edge around entire perimeter of each leaf.
Microswords appear to be unaffected. Look healthy.
Baby tears (hemianthus glomeratus) appear to be basking in the CO2 glow. The tops are 50% larger than the bottoms. Look healthy.
Corrective measures up to this point:
50% water change
Dose NPK (1.2mL of each Pfertz)
Cut dead and dying DHG down to substrate and remove trimmings.
Is there anything else I should do? I took a bath this morning. Please help!