200 GALLON JUNGLE STYLE

Paul G

Active member
Yesterday 25 ml of KNO3 solution was added, and the water change regimen schedule was restarted.

Today's numbers

pH: 6.81
ORP: 444 mV
EC: 1050 uS/cm
NO3: 2.7 ppm
PO4: 2.29 ppm
Fe: 0.27 ppm
K: 35 ppm
GH: 60 ppm (3.37 deg)
Ca / Mg: 44 ppm / 16 ppm
KH: 7.87 deg

The numbers for pH, ORP, and EC are seven day running averages. The EC probe was cleaned and calibrated on 29 Nov and has been consistent.
 

Paul G

Active member
I always run the tests at around 08:00, about an hour after dosing, but today I tested at 17:00.

Today's numbers

pH: 6.81
ORP: 454 mV
EC: 1040 uS/cm
NO3: 0.1 ppm
PO4: 1.17 ppm
Fe: 0.25 ppm
K: 40 ppm
GH: 64 ppm (3.6 deg)
Ca / Mg: 42 ppm / 22 ppm
KH: 7.98 deg

After this test I added 25 ml of KNO3 solution.
 
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Paul G

Active member
Today's numbers

pH: 6.81
ORP: 465 mV
EC: 1020 uS/cm
NO3: 0.9 ppm
PO4: 0.51 ppm
Fe: 0.26 ppm
K: 40 ppm
GH: 68 ppm (3.82 deg)
Ca / Mg: 48 ppm / 20 ppm
KH: 8 deg

After this test I added 25 ml of KNO3 solution.
 

Paul G

Active member
Today's numbers

pH: 6.81
ORP: 471 mV
EC: 1000 uS/cm
NO3: 0
PO4: 1.06 ppm
Fe: 0.3 ppm
K: 40 ppm
GH: 60 ppm (3.37 deg)
Ca / Mg: 48 ppm / 12 ppm
KH: 7.87 deg

After this test I added 25 ml of KNO3 solution. At the current water change rate, the system wants a minimum daily dose of this solution of 10 ml.

At this time, the aragonite reactor is supplying the entire ++Ca requirement. The CaCl2 solution doser is not being used daily, so I can re-task this for KNO3. If in future there is a need for supplemental Ca, I could go back to adjusting this solution with Ca(NO3)2.

While I know that the NeoMag reactor is supplying ++Mg, it is necessary to dose 12.5 ml of MgSO4 solution daily.
 

Paul G

Active member
Today's numbers

pH: 6.76
ORP: 517 mV
EC: 1140 uS/cm
NO3: 0
PO4: 0.13 ppm
Fe: 0.18 ppm
K: 35 ppm
GH: 44 ppm (2.47 deg)
Ca / Mg: 28 ppm / 16 ppm
KH: 6.35 deg

I have been letting the aquarium run without a lot of tweaking and a minimum of testing. Also have let the plants go wild; no pruning for the last couple of weeks. It is time for filter servicing. Now, I am trimming and starting in on some much needed housekeeping.
 

Paul G

Active member
Today's numbers

pH: 6.77
ORP: 521 mV
EC: 1150 uS/cm
NO3: 1.1 ppm
PO4: 0.93 ppm
Fe: 0.29 ppm
K: 50 ppm
GH: 52 ppm (2.93 deg)
Ca / Mg: 34 ppm / 18 ppm
KH: 6.85 deg
 

Paul G

Active member
Today's numbers

pH: 6.78
ORP: 527 mV
EC: 1130 uS/cm
NO3: 2.7 ppm
PO4: 0.27 ppm
Fe: 0.27 ppm
K: 40 ppm
GH: 52 ppm (2.93 deg)
Ca / Mg: 34 ppm / 18 ppm
KH: 6.85 deg

Changed out the intake strainers. Scraped the front glass. Just a little slow-growing periphyton, but no other algae anywhere.

I have delayed restarting KNO3 supplement as I proposed on the 17th, hoping to see occasional non-zero test results. I have been feeding fresh frozen and green sinking liberally. Both NO3 and PO4 are resulting as autochthonous nutrient, albeit in the low numbers I have become accustomed to seeing. NO3 is showing up, so I will not be supplementing; the NO3 is being evolved and it is being removed by both the water changes and consumption by the plants. The plants are flourishing. They want for nothing. As long as the fish are eating, I will not worry about persistently low nutrient. I am getting a thriving, dense jungle with no algae in super-oligotrophic conditions. Actual results speak for themselves; the numbers are signposts, not goals.

The powerhead internal filters have not been running for a couple of weeks. The aragonite and NeoMag in filter loop 1R are providing all the ++Ca, most of the ++Mg, and some of the --CO3 buffer. I will remove the internal filters.

The K2CO3 / Alkaline Buffer dosing is holding up consistent values of +K and dKH.
 

Paul G

Active member
The 7 day running averages for pH: left end is 6.78 and right end is 6.84. Both electrodes are in calibration. It is pH-L that is used for the CO2 controller. This is programmed to inject carbon at pH > 6.82. There is considerable "overshoot" in the pH-L solenoid operation due to the relative velocities of injection rate and circulation/diffusion to the electrode. So pH-L averages below the programmed threshold. pH-R follows in lockstep but averages above the programmed threshold. Having a CO2 diffusor at both ends of the tank is necessary in a large tank. The discrepancy is more pronounced with the right end diffusor shut off. The constant average of pH-L and pH-R is 6.81, which I accept as conforming to the set threshold. I am satisfied that it is normal operational behavior of the CO2 and circulatory systems because it is consistent and free of incidental anomalies. It represents about + or - 3 ppm variability in CO2 concentration of 33 ppm at the prevailing dKH, now attempting to hold at about 7 degrees. The CO2 utilization rate is down since I raised the pH control value from 6.7 to 6.82 at the last bottle change. That was 9 November - two months ago! Surely, this bottle is about done.



Today's numbers

ORP: 531 mv
EC: 1110 uS/cm
NO3: 2.4 ppm
PO4: 1.14 ppm
Fe: 0.28 ppm
K: 50 ppm
GH: 56 ppm (3.15 deg)
Ca / Mg: 36 ppm / 20 ppm
KH: 6.52 deg

Returning to a recent discussion, these pictures show fairly well how the tank looks on the surface. This condition reflects the appearance I like as a rule, with plants at the waterline, lots of floating leaves, extensive shade, dense undergrowth at all levels. The light in these shots is just before full daylight. It penetrates fairly well, although it's very shady on the floor. Crypts and ferns get what they need and are robust. The controlled light probably helps with algae suppression. The fish like this jungle. It is natural shelter.










 
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Paul G

Active member
Sunday, 10 Jan 2021, at 10:45, CO2PRIMARY emptied. This bottle delivered 112 hours over 61 days, an average of 1 min 50 sec per day. This is an approximate 33% reduction in the utilization rate over the last cycle. The last bottle change was 9 Nov, and on 13 Nov I changed the pH from 6.7 to 6.82. I have now upped it again, to 6.85, and am making an effort to lower alkalinity just a little. The objective here, as stated previously, is to throttle the system as much as possible without having to lower the light intensity. This is not only to reduce the net CO2 utilization, but also slow down the growth some. The lights are set for about 80% of maximum, and if I can maintain the general shadiness and favorable redox I believe I can remain algae free without attenuating energy input.

The total elapsed time numbers for emptying rate of the bottles has been historically variable. These are 20 lb, nominally, fully charged. How precisely this corresponds to an actual volume value is sketchy, but it shouldn't be surprising to see discrepancies in hours worth of controlled slow discharge. Since there are periods when vigorous aeration is used, the aquarium itself is variably lossy with respect to injected CO2. It is impossible to parse the initial deficit from the cumulative loss by just simple observation of elapsed time of discharge.

Toward the goal of ensuring low DOM, I am experimenting with activated carbon.

Today's numbers

pH: 6.79*
ORP: 531 mV
EC: 1120 uS/cm
NO3: 0 ppm
PO4: 0.47 ppm
Fe: 0.15 ppm
K: 45 ppm
GH: 52 ppm (2.92 deg)
Ca / Mg: 36 ppm / 16 ppm
KH: 6.69 deg

*Seven day running average; at 11:00 today pH-L is 6.85.

Generally, parameters are just a little down from Saturday. Yesterday, 11 Jan, I changed filters in high velocity loops 2 and 3, which resulted in around a 6 gallon water change, so no surprise here.
 

Paul G

Active member
Today's numbers

pH: 6.85*
ORP: 527 mV
EC: 1150 uS/cm
NO3: 0.9 ppm
PO4: 0.9 ppm
Fe: 0.19 ppm
K: 35 ppm
KH: 6.46 deg
GH: 56 ppm (3.15 deg)
Ca / Mg: 40 ppm / 16 ppm

*Average of the 7 day running averages of pH-L and pH-R. From here on, reported pH will be presented in this manner. I am establishing more rigor in the calibration intervals for the probes. To start, the probes will be cleaned and calibrated every thirty days, always at the same time.

At the current pH and dKH, CO2 concentration in the water column is approximately 25 ppm. If the fact that O2 continues to peak daily at saturation (9 ppm) is any indication, carbon fixation proceeds apace and the CO2 delivery is adequate for the plants' demands. I do not expect that a slowing of growth by CO2 reduction will be immediately obvious, especially with no change in the light intensity. I certainly have not noticed such slowing, or any other deleterious effects.

It is time already to change out the intakes. Leaf litter accumulates and decays in situ in the water stream, releasing DOM - particularly complex aromatic acids such as humics, tannins, etc. A little of this goes a long way in making aquarium water more bio-friendly; too much encourages nuisance algae in my view. I don't find the build-up of rotting plant matter at this high rate especially unusual. There is a lot of vegetation in this tank, and vigorous life necessarily brings concomitant senescence. The intake screens are mechanical pre-filters, and making it easy to change them is essential.

The flow rates are more measurably slowed by accumulation on the intakes than by impediments anywhere else in the system, including the 25 micron polishing filters. While the streaming water change regimen has proven its worth in controlling DOM, there are means readily at hand for improving organics removal. I am now experimentally including pelleted bituminous-based activated carbon in one of the high velocity filter loops to immediately intercept these decomposition products while they are still large molecules. Since I test for every significant parameter on an almost daily basis I am well-placed to evaluate the effect of this on the concentrations of supplements being deliberately added to the system. Reasons have been given why I have eschewed activated carbon in this system, and they are the same as those given by others who have rationally argued against the use of AC. This experiment is designed to determine, not whether these reasons are valid on a theoretical basis (I think largely they are), but rather whether advantages exceed disadvantages in actual long-term results. Is the significance of the relative benefit of using AC borne out empirically? I am using one liter of high quality pelleted AC in one filter loop running over 450 gph, changed monthly. I have begun the second month. This is driving redox further upward. I am not seeing any effect on testable nutrient concentrations. If there are effects exhibited by health of the plants, that will require more time to determine.
 

Paul G

Active member
Yesterday's numbers

pH: 6.83
ORP: 528 mV
EC: 1160 uS/cm
NO3: 0
PO4: 2.23 ppm
Fe: 0.24 ppm
K: 35 ppm
KH: 6.29 deg
GH: 50 ppm (2.81 deg)
Ca / Mg: 30 ppm / 20 ppm
 

Paul G

Active member
Today's numbers

pH: 6.83
ORP: 527 mV
EC: 1180 uS/cm
NO3: 0
PO4: 0.02 ppm
Fe: 0.14 ppm
K: 40 ppm
KH: 5.96 deg
GH: 52 ppm (2.92 deg)
Ca / Mg: 36 ppm / 16 ppm
 
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