My Iwagumi Aquascape Journey Part 2: Grow Out

In Part 1, I detailed the beginning of my journey from an idea to a flooded and cycling Iwagumi style aquarium. In part 2, I will cover what I've done since flooding the aquarium. I performed numerous water changes, countless parameter tests, light and flow adjustments, and trimmings.
My goals were to have a beautiful aquarium and learn all I could about this aquascaping style. There were only a few things I would have done sooner If I could do it again, but so far, nothing I regret.
The final leg of the journey will be adding livestock, which I'll discuss in part 3. For now though, let me show you what I've managed so far.
Water Changes
After the flooding, I waited 24 hours and did a water analysis for ammonia (NH3), ammonium (NH4+), nitrite (NO2-), nitrate (NO3-), pH, carbonate hardness (KH), and general hardness (GH).
5/6/22 - 4:00 pm - No Water Change
pH | 6.2 |
KH | 0 dKH |
GH | 3 dGH |
NH3/NH4+ | 8+ ppm |
NO2- | 0.25 ppm |
NO3- | 5 ppm |
CO2 | 9.3 ppm |
I expected the free and total ammonia to be high because nitrogen leaches from the soil readily at first. However, I did not expect it to max out my test kit at over 8 ppm. I added 1.5 grams of alkalinity (KH) buffer directly to the tank and did not perform a water change.
5/7/22 - 5:00 pm - 1st Water Change
pH | 6.0 |
KH | 2 dKH |
GH | N/A |
NH3/NH4+ | 8+ ppm |
NO2- | 1 ppm |
NO3- | 10 ppm |
CO2 | 59 ppm |
The nitrogen cycle is in full swing, there was no sign of algae growth after 48 hours. With some alkalinity in the water, CO2 shot up to 59 ppm at 1.0 bubbles per second. I added 3 g of KH buffer and 3 g of equilibrium (GH buffer) to the 4 gallon water change I performed.
5/8/22 - 4:00 pm - No Water Change
pH | 6.2 |
KH | 2 dKH |
GH | 3 DGH |
NH3/NH4+ | 8+ ppm |
NO2- | 1 ppm |
NO3- | 10 ppm |
CO2 | 37 ppm |
On day three, I did not perform a water change. I added 1.5 g of KH buffer directly to the tank (after dissolving in a ½ cup of tank water). I increased CO2 to 1.25 bubbles per second.
I measured bubbles per second, by starting a stopwatch and counting bubbles for what felt like about ten seconds. I then stopped the timer and divided the bubbles I counted by the seconds displayed on the watch. I say what “felt” like ten seconds because you don’t want to look away from the bubbles you're counting to check the stopwatch.
If you count 18 bubbles and the stopwatch reads 13 seconds, that's 1.38 bubbles per second. The longer you count, the more accurate your calculation will be.
5/10/22 - 5:45 pm - 2nd Water Change
pH | 6.0 |
KH | 2.5 dKH |
GH | 3 dGH |
NH3/NH4+ | 8+ ppm |
NO2- | 5 ppm |
NO3- | 30 ppm |
CO2 | 73 ppm |
The nitrogen cycle is beginning to peak with nitrites at 5 ppm. I added 2 g of KH buffer and 3.2 g of GH buffer to the 4 gallon water change.
5/13/22 - 5:00 pm - 3rd Water Change
pH | 6.2 |
KH | 2.0 dKH |
GH | 3.0 dGH |
NH3/NH4+ | 8+ ppm |
NO2- | 5 ppm |
NO3- | 5 ppm |
CO2 | 37 ppm |
On day 8 and water change three, I add 3 g of KH buffer and 3.2 g of GH buffer to a 4 gallon water change. No algae and the hair grass is growing rapidly.

5/15/22 - 4:00 pm - 4th Water Change
pH | 6.2 |
KH | 3.0 dKH |
GH | 5.0 dGH |
NH3/NH4+ | 8+ ppm |
NO2- | 5 ppm |
NO3- | 5 ppm |
CO2 | 56 ppm |
Another water change with 1.2 g of KH buffer and 3.2 grams of GH buffer added to the 4 gallon water change.
5/17/22 - 1:30 pm - 5th Water Change
pH | 6.2 |
KH | 2 dKH |
GH | 5 dGH |
NH3/NH4+ | .25 ppm |
NO2- | 5 ppm |
NO3- | 5 ppm |
CO2 | 37 ppm |
Finally, the ammonia drops to .25 ppm. I completed a 5th water change with 1.5 g of KH buffer and 3 g of GH buffer added to a 4 gallon water change. I also added a half dose (0.5ml) of Flourish, an all in one plant fertilizer.
5/19/22 - 6:20 pm - No Water Change
pH | 6.2 |
KH | 2.0 dKH |
GH | 6 dKH |
NH3/NH4+ | 0.1 ppm |
NO2- | 0 ppm |
NO3- | 50 ppm |
CO2 | 37 ppm |
The nitrogen cycle is almost complete. I added another half dose (0.5 ml) of Flourish and 1.5 g of KH buffer directly to the tank. There is calcium and magnesium in the fertilizer. If the plants are not absorbing it fast enough, this may explain why the GH is increasing.
5/22/22 - 4:30 pm - No Water Change
pH | 6.2 |
KH | 3 dKH |
GH | 6 dGH |
NH3/NH4+ | N/A |
NO2- | N/A |
NO3- | 80 ppm |
CO2 | 56 ppm |
The nitrogen cycle is complete and nitrate continues to rise.
5/27/22 - 3:00 pm - 6th Water Change
pH | 6.4 |
KH | 2.5 dKH |
GH | 6 dGH |
NH3/NH4+ | N/A |
NO2- | N/A |
NO3- | 80 ppm |
CO2 | 73 ppm |
PO4+ | 0.00 ppm |
Phosphates tested at 0 ppm. Performed a 4 gallon water change with 1.2 g of KH buffer and 4.2 g of GH buffer added.
6/12/22 - 2:00 pm - 7th Water Change
pH | 6.4 |
KH | 3.5 dKH |
GH | 6 dGH |
NH3/NH4+ | N/A |
NO2- | N/A |
NO3- | N/A |
CO2 | 41 ppm |
Waiting two weeks between water changes to allow plants to soak up as many nitrates as they could. I continued to dose 0.5 ml of Flourish twice weekly. Performed a 4 gallon water change with 1.2 g of KH and 3 g of GH buffer.
5/8/22 - 4:00 pm - No Water Change
pH | 6.4 |
Kh | 3.0 dKH |
GH | 8 dGH |
NH3/NH4+ | N/A |
NO2- | N/A |
NO3- | 80 ppm |
CO2 | 35 ppm |
Continuing to dose fertilizer without a water change increased GH to 8 dGH, higher than I would like. Performed a 4 gallon water change with 1.2 g of KH and 2 g of GH buffer added.
5/8/22 - 4:00 pm - No Water Change
pH | 6.4 |
KH | 4 dKH |
GH | 6 dGH |
NH3/NH4+ | N/A |
NO2- | N/A |
NO3- | N/A |
CO2 | 47 ppm |
4 gallon water change with 1 g of KH and 2 g of GH buffer added.
5/8/22 - 4:00 pm - No Water Change
pH | 6.4 |
KH | 6 dKH |
GH | 10 dGH |
NH3/NH4+ | N/A |
NO2- | N/A |
NO3- | N/A |
CO2 | 118 ppm |
After a month of no water change and just adding Flourish twice weekly, the general hardness climbed significantly. I suspect this is the case be