200 GALLON JUNGLE STYLE

Paul G

Active member
Today's numbers

pH: 6.70
ORP: 513 mV
TDS: 290 ppm (@ 07:31)
NO3: - n/t -
PO4: 0.36 ppm
K: - n/t -
Fe: 0.05 ppm (@ 07:00)
dKH: 6.95
dGH: 3.58
Ca: 14.40 ppm
Mg: 6.83 ppm
Ca/Mg: 2.1/1

Filter changes done this AM. Water change was about 4 gallons (15 liters).

LOOP1L velocity 141 gph
Stage 1: 100 micron mechanical, no core medium
Stage 2: 25 micron mechanical, 1008 grams Renew

LOOP1R velocity 104 gph
Stage 1: 100 micron mechanical, 250 mL Purigen
Stage 2: 25 micron mechanical, HRR

LOOP2 velocity 316 gph
Stage 1: 100 micron mechanical, no core medium
Stage 2: empty

LOOP3: velocity 295 gph
Stage 1: 100 micron mechanical, no core medium
Stage 2: empty
 

Paul G

Active member
Today's numbers

pH: 6.70
ORP: 517 mV
TDS: 290 ppm (@ 07:37)
NO3: 2.66 ppm
PO4: 0.29 ppm
Fe: 0.16 ppm (@ 07:38)
K: 40 ppm
dKH: 7.00
dGH: 3.58
Ca: 12.80 ppm
Mg: 7.80 ppm
Ca/Mg: 1.6/1

This suggests that SWCR is overrunning HRR Ca++ production. While Ca/Mg is falling, GH is not, so the MgSO4 dose rate probably can be reduced somewhat. I do not want to reduce the water change rate, so I will install additional HRR. Experimentally, MgSO4 goes from 60 mL to 45 mL per day, and I am adding 500 grams CaribSea crushed shells substrate to LOOP1L Stage 1.

All the macros and iron are where I like them. At present, 10 mL SeaChem Nitrogen is being dosed once per day at 06:00. Orthophosphate is not being supplemented at all; all phosphorus is autochthonous.

The redox is extremely high; while I presume that that is an indicator of low DOM, I will not be misled into profligate feeding patterns again.

The filter change interval must not exceed 3 weeks. The 100 micron filters in the high velocity loops are fairly dirty after 17 days.
 

Paul G

Active member
Today's numbers

pH: 6.7
ORP: 520 mV
TDS: 290 ppm (@ 07:25)*
NO3: - n/t -
PO4: 0.34 ppm
Fe: 0.17 ppm (@ 07:07)
K: - n/t -
dKH: 6.89
dGH: 4.03
Ca: 17.60 ppm
Mg: 6.83 ppm
Ca/Mg: 2.6/1

The added aragonite has reversed Ca++ decline in a 20 hour period, and Mg++ is moderating, with a half degree of GH increase resulting. Is the CaribSea medium more readily soluble (faster reacting) than Reef Reactor? Today's results were the goal, but it appears that HRR may start outrunning the SWCR. I suspect this will come down to decreasing the aragonite mass until the desired equilibrium is attained. Some tinkering is therefore still necessary, but this is assurance that the balance can be struck without compromising the SWCR rate, which is about 1.5 gph.

*The TDS readout is jumping between 290 and 300 ppm this AM, so is on the cusp.
 

Paul G

Active member
Today's numbers

pH: 6.69
ORP: 524 mV
TDS: 300 (@ 07:00)
NO3: - n/t -
PO4: 0.47 ppm
Fe: 0.34 ppm (@ 06:54)
K: - n/t -
dKH: 7.17
dGH: 4.03
Ca: 17.60 ppm
Mg: 6.83 ppm
Ca/Mg: 2.6/1

Twenty-four hours since previous test results. GH and Ca/Mg are unchanged. KH is up slightly, likely from increase in CaCO3 from the HRR addition. TDS is stable 300 ppm. It is encouraging to see results that confirm predictions.
 

Paul G

Active member
At 15:30 today, CO2PRIMARY emptied. This 10 lb cylinder delivered a total of 143 hours in 17 days.
 

Paul G

Active member
Today's numbers

pH: 6.69
ORP: 525 mV
TDS: 300 ppm (@07:58)
NO3: - n/t -
PO4: 0.34 ppm
Fe: - n/t -
K: 40 ppm
dKH: 6.55
dGH: 4.26
Ca: 19.2 ppm
Mg: 6.83 ppm
Ca/Mg: 2.8/1

Mg++ holding steady; Ca++ inclining, accounting for all the GH gain. The added HRR is overrunning the SWCR. I am reducing the mass of the aragonite charge from 500 grams to 200 grams. Just estimating here, but this is easy to do. These Ca++ and GH values are certainly acceptable, but the upward drift should be stemmed or this habitat will leave "soft-water" territory. I believe it is feasible to maintain a GH of 4.0 degrees and a Ca/Mg of 2.5/1 by means of this method. Also, it is shown that with dosing K2CO3 solution K+ can be supported at 35 to 40 ppm without exceeding dKH 7.

I think I should clarify my rationale for maintaining the KH at this relatively high value. This concept is essential to the high tech high light (HTHL) methodology. The KH is the buffer system.* In concert with the pH it determines the CO2 content, and higher KH permits safe CO2 injection above atmospheric equilibrium by enabling the water to resist drastic acidity drops. It is preferable to moderate the pH value closer to circumneutral so that the biological filter efficiency is not compromised. Acidity downslope from 6.8 begins to retard nitrification to a significant degree**, so if a CO2 concentration over 30 ppm is wanted, the KH will need to be kept high in order for the buffer to hold the pH stable. Generally in water wherein the GH is a particular value and the CO2 content is in natural equilibrium with the air (i.e. not enriched by injection), the KH will usually be pretty much in the same range, and will be in a constant ratio with GH. The GH and KH in natural waters are thusly coupled. The KH is a measure of the CO3-- (carbonate) concentration supplied by dissolution of K2CO3, CaCO3, and MgCO3, just as the GH is a measure of the Ca++ and Mg++ parts. Except to the extent that carbonate buffers against pH change resulting from carbonic acid (dissolved CO2) formation, it is not per se a sensible parameter to organisms in the water. It is just a number. The pH, on the other hand, materially impacts osmoregulatory and metabolic enzyme mechanisms, as does GH and other ionic components. Thus, in a HTHL aquarium, KH is treated as an entity decoupled from GH, becoming a separately manipulable parameter for control of CO2 solution. I prefer a stable pH at 6.7 because I can get 40 ppm CO2 by supplying sufficient carbonate to suitably elevate the KH. But this is the reason for provision of large bio-filtration capacity, as 6.7 pH is not optimal for efficient nitrification, so the shortfall is compensated by culture area.
----------------------------------------------------------------------------------

*Buffer systems: Google it. Most general/inorganic chemistry textbooks will cover this. For a quick dissertation on the web see

SeaChem.com > Resources > Articles > Understanding the General Chemistry of the Planted Aquarium by Gregory Morin PhD
-----------------------------------------------------------------------------------

**Typical aerobic autotrophic population kinetics plotted against pH depict a bell-shaped curve whereon the optimal growth rate occurs in the region just above pH 7 (Nitrosomonas, for instance, exhibits maximal activity at pH 8). In engineered biological nutrient removal (BNR) systems, adequate nitrification can be had in nitrifying cultures that have become acclimated to a lower pH, but performance hinges on solid stability of pH and maintenance of high DO. This is why a pH 6.5 can actually work well. No surprise to aquarists. But the effectiveness of nitrification is very sensitive to oxygen availability, and once acclimated the culture will not well tolerate sudden pH changes. Nitrification is a process of acidifying reactions, so a properly robust biological filter destroys buffer. Thus BNR systems tasked with DIN removal require refreshment of alkalinity and will exert a significant portion of the overall biological oxygen demand on the habitat. An aquarium's biological filter is in fact a BNR. This gets more technical than is necessary for hobbyist's purposes, but those wanting more of this stuff should check out

Grady, C.P. Leslie; Glen T. Daigger; Henry C. Lim Biological Wastewater Treatment, 2nd Ed 1999: Taylor and Francis Group, CRC Press
 
Last edited:

Paul G

Active member
Today's numbers

pH: 6.7
ORP: 527 mV
TDS: 310 ppm (@ 07:30)
NO3: - n/t -
PO4: 0.26 ppm
Fe: 0.08 ppm (@ 07:23)
K: - n/t -
dKH: 7.23
dGH: 4.37
Ca: 18.40 ppm
Mg: 7.80 ppm
Ca/Mg: 2.4/1
 

Paul G

Active member
Today's numbers

pH: 6.7
ORP: 528 mV
TDS: 300 ppm (@ 06:58)
NO3: - n/t -
PO4: 0.35 ppm
Fe: 0.29 ppm (@ 06:57)
K: - n/t -
dKH: 6.78
dGH: 3.81
Ca: 18.40 ppm
Mg: 5.37 ppm
Ca/Mg: 3.4/1

I am noticing the continued obstinacy of less than crispy clear conditions in this tank that I have attributed to cyanobacteria (blue-green algae), including the surface film. Four days ago, I removed all the flat cobbles and pebbles from the foreground and have left them out. I got these soaking in a bleach solution to clean them up. I scraped the glass down to the bottom thoroughly. This will always have blue-green below the gravel line due to settlement and decay of particulate organic matter (POM). The general circulation of tank water does involve exchange in this gravel layer; it is not completely shut off from the tank. That is to say, this is the normal state of the benthos in a healthy ecosystem.

The foreground gravel layer is very shallow, between 1" to 2" in front of the mid-tank retaining wall. Further back the gravel bed thickens; here the established root systems of the jungle have set up a healthy mature rhizo-sphere. There are no flat rocks laying on top of this gravel bed. The flat rocks in the foreground were stacked to provide little grottos for the loaches and catfishes, and the whole forward area arranged to resemble a stream bed with cobbles and pebbles completely overlying the gravel bed. Much of the rock was set on top of, in contact with, the gravel line. This severely retards circulation of the tank water in the foreground gravel bed. The benthos here, with this layer of stones, was significantly starved of O2. Anaerobic conditions have been encouraged and toxic DOM was subtly pervading the water column.

This hardscape plan was begun after the turnaround and described in previous entries above, and the tank has been difficult ever since. I would see the surface film continually return, among other symptoms, the cause of which was a total mystery to me, and wondered just what could possibly be going wrong in this system with all the water changes, heterotroph supplementation, oxygen saturation, and chemical filtration. The super high redox in the water column reflected this, but the ORP in the foreground gravel bed must have been abysmal.

Then I took out the rocks. Hardscape is great, of course, and as far as I'm concerned the big flat rocks are necessary for keeping loaches and corys, but you can't pave the entire gravel bed or you'll shut off the oxygen. I hesitate to think how bad things could have gotten were it not for the SWCR and the other measures taken. The big flat cobbles will go back in, but care will be taken to elevate all of them off the gravel line.
 

Paul G

Active member
Today's numbers

pH: 6.68
ORP: 533 mV
TDS: 290 (@ 07:06)
NO3: 4.4 ppm
PO4: 0.39 ppm
Fe: 0.24 ppm (@ 06:52)
K: 40 ppm
dKH: 6.33
dGH: 3.59
Ca: 16.00 ppm
Mg: 5.85 ppm
Ca/Mg: 2.7/1

I had not tested since last Tuesday and was very pleased to see all the hardness numbers coming in exactly as predicted without any tinkering over this five day period. The background chemistry is stable and well controlled.

Nutrient is a little higher than what I would call the previous normal, but within bounds definable as oligotrophic. With PO4 and NO3 inclining, I suspect DOM will present accordingly, even though elevated ORP continues. Today I will install a GAC charge in a high velocity loop and run that for the next week until the regular filter change.

The micronutrient doser vat mix is now 1350 mL Flourish Comprehensive : 150 mL Fe++Gluconate solution (112 g/L DW).

This AM I added 200 mL Waste-Away and am running aeration full time.

Both of the new Nymphaea lotus v rubra (bulbs planted weeks ago) have finally sent out floating leaves.
 

Paul G

Active member
I placed 400 g of bituminous GAC in each high velocity loop. The state of the 100 micron filters in these loops now only 12 days tells me I should change them weekly. These get dirty much more quickly than the 100 micron filters in the processing loops.
 

Paul G

Active member
Today's numbers

pH: 6.7
ORP: 533 mV
TDS: 290 ppm (@ 07:32)
NO3: - n/t -
PO4: 0.34 ppm
Fe: 0.14 ppm (@ 07:35)
K: - n/t -
dKH: 6.78
dGH: 64
Ca: 15.20 ppm
Mg: 6.34 ppm
Ca/Mg: 2.4/1
 

Paul G

Active member
Today's numbers

pH: 6.67
ORP: 533 mV
TDS: 290 ppm (@ 07:30)
NO3: 4.4 ppm
PO4: 0.58 ppm
Fe: 0.01 ppm (@ 07:13)
K: 40 ppm
dKH: 6.72
dGH: 3.59
Ca: 16.00 ppm
Mg: 5.85 ppm
Ca/Mg: 2.7/1

Again, all the background chemistry is holding steady with no ad hoc adjustments. The HRR, MgSO4, and K2CO3 auto-dosing are staying in balance with the SWCR. Despite the feeding austerity, PO4 and NO3 are trending high. All plant nutrients are more than adequate, at least in terms of water column abundances, so there should be no impediment to growth. The foliar uptake and the SWCR working together are not diluting autochthonous product quite as rapidly as it evolves. Today I am doing a 10% "big gulp" water change and will skip feeding.
 

Paul G

Active member
Today's numbers

pH: 6.68
ORP: 534 mV
TDS: 260 ppm (@ 06:44)
NO3: 3.8 ppm
PO4: 0.09 ppm
Fe: 0.40 ppm (@ 06:43)
K: 40 ppm
dKH: 6.33
dGH: 3.36
Ca: 15.2 ppm
Mg: 5.36 ppm
Ca/Mg: 2.8/1

The "big gulp" water change (about 10%) had the effect I expected across the board. The high Fe this AM is, of course, a result of testing within around a half hour of the dosing time, so it would not be affected.
 

Paul G

Active member
Today's numbers :geek:

pH: 6.7
ORP: 535 mV
TDS: 260 ppm (@ 07:15)
NO3: - n/t -
PO4: 0.19 ppm
Fe: - n/t -
K: - n/t -
dKH: 6.23
dGH: 3.58
Ca: 16.8 ppm
Mg: 5.36 ppm
Ca/Mg: 3.1/1
 
Last edited:

Paul G

Active member
Today's numbers

pH: 6.68
ORP: 535 mV
TDS: 270 ppm (@ 07:47)
NO3: 3.1 ppm
PO4: 0.26 ppm
Fe: 0.22 ppm (@ 07:40)
K: 35 ppm
dKH: 5.94
dGH: 3.25
Ca: 15.20 ppm
Mg: 4.88 ppm
Ca/Mg: 3.1/1
 

Paul G

Active member
Over the past few months I have been increasingly dissatisfied with the progress of this system. I have hypothesized about the various possibilities explaining the deterioration, believing in each case that the cause had been found. I do think I identified some poor practices and implemented fixes, but I never achieved true resolution. There is something very wrong here, and it is necessary to question preconceptions to gain a clear perspective. The water quality parameters which are so closely monitored and controlled appear to be ideal, but there is something - something subtle but important - that I am missing.

I have to review everything that has been done differently since before the turnaround. I have changed the lighting, removing the BML strips and adding more Kessil A80 Tuna Suns. I have greatly increased the daily volume of water being changed in the SWCR program. And then there was the turnaround itself; did I upset something in the substrate that has defied natural repair, or was it not sufficiently thorough? I cannot think of anything else - yet.

Without definitely ruling out any possibilities, I will make a beginning with tentative assumptions that it is likely not a problem with the lights or with the turnaround procedure.

With the SWCR came the rationale that it was a means to attain oligotrophy, the whole point being to dilute autochthonous product, particularly DOM. With persistently very high redox which indicates low DOM, the system kept "looking like" a DOM problem in the making. The effort to stem this was a more aggressive SWCR which led to super-oligotrophy. I should have more confidence in the technology than that; ORP monitoring is not tricky or prone to failure. If the ORP monitor is reporting 500 mV, I don't have a severe problem with dissolved organics! Prolonged super-oligotrophy is essentially a low-grade malnutrition problem for the plants, but not for algae or cyano. So begins an experiment to allow a rise in nitrate concentration. Nitrate is the least preferred nitrogen source for macrophytes as they have to expend energy to use it, but it is the only real source available to them in this system. It may be that phosphate has been a bit too lean also.

I have devised an automated method for obtaining oligotrophy with stable background chemistry. It might seem that the way out of this difficulty is to build on this achievement by providing the direct corrective of upping the NO3 dose. I'm not so sure of that. I had excellent redox before I amped up the SWCR. It makes more sense to return to a lesser water change volume, recalibrate the dosers, and simplify the schedule. As long as ORP is high, the system is diluting. In any case, this will be a reset to the management protocol in use before the turnaround.
 

Paul G

Active member
I have rescheduled the ODEs for each hour from 23:00 to 06:00 inclusive, for a total of 8 times overnight. Tonight I will disable auto-top-off and get a metric in the morning of the ODE volume. This hasn't been verified for several months. Since there will be no ODEs during daylight hours, all dosing events will be performed in the 06:00 - 07:00 hour daily, with no mid-day follow-ons. There will be a need to experiment with the dosing timers to calibrate the doses for balance with the revised SWCR. I won't publish those test results until the system settles down and the tinkering nears conclusion. For now, I have reduced the HRR aragonite charge to 200 g. It may be possible that the HRR will be discontinued entirely, replaced by CaCl2 or Ca(NO3)2 auto-dosing. I remain fully open to whatever will work.

Today was filter change day and chemical filtration media will be left out for now. The consequent water change was about 6 gallons. I installed 25 micron filters in Stage 2 of both high velocity loops. At this time, all mechanical filter cores are running empty.
 

Paul G

Active member
Today's numbers

pH: 6.8
ORP: 533 mV
TDS: 320 ppm
NO3: 6.6 ppm
PO4: 1.19 ppm
K: 40 ppm
Fe: 0.33 ppm
dKH: 7.0
dGH: 3.5
Ca: 16.8 ppm
Mg: 4.9 ppm
Ca/Mg: 3.4/1

I have satisfied my curiosity on a few points over the last year by actually experimenting and observing changes in this aquarium. Declarations as to what things "succeeded" and what things "failed" are conditional. In experimentation, all things just lead to data.


Streaming Water Change Regimen

The SWCR as a practical means of controlling rate of dilution works. It is possible to fine tune the solution state of allochthonous and autochthonous matter through a continuous, or continuously metered, water change protocol. The advantage of SWCR over periodic "big gulp" water changes is the inherent relative stability of the water chemistry; essentially, there are no sudden changes. The SWCR is an important feature of automated systems. All other water change methods are necessarily episodic.

Hardness Reconstitution Reactor

The HRR, simply an aragonite medium placed in the flow of a filter loop, is an effective means of regulating GH and KH in an SWCR system. The mass of the filter charge and the flow rate must be adjusted for balance with the dilution rate. This is a method of reconstituting calcium in RO/DI source-water with the benefit of also refreshing the carbonate buffer. The aragonite alone should not be expected to contain sufficient magnesium to support the requirement for a densely planted tank, necessitating supplementation with MgSO4. It will likely also be insufficient as a sole source of carbonate.

The Advantage of K2CO3 Auto-dosing

It is clear from the analysis history that when the dose rate of K2CO3 is adjusted to supply sufficient alkalinity to maintain a minimum 30 ppm CO2 at pH 6.7 to 6.8, the concentration of potassium, an essential macronutrient, is held at a minimum of 30 ppm. This supplement supports both luxury foliar uptake of potassium and the core buffer system for a CO2 injected, or "high-light/high-tech", aquarium. Renewed KNO3 supplementation is an additional source of potassium.

Re-evaluation of the Optimal Trophic State of a Planted Ecosystem

The SWCR and auto-dosing system made it possible to manipulate certain water quality parameters which required intensive testing and trial procedures to implement. When this journal started, the ecosystem was mesotrophic, having nitrate and orthophosphate at 10+ ppm and 3+ ppm respectively. Also, at that time redox was quite good and I was not routinely using any chemical filtration. To the point, plants thrived and algae were well controlled. I began an exploration into the possibility of "low-nutrient", or oligotrophic, management criteria; how far can this envelope be pushed in a densely planted tank? I assume, I think rightly, that the lowest nutrient concentrations possible compatible with plant health is the generally desirable goal. What those concentration values are requires verification. The following observations result from that experiment.

1) If "low-nutrient" and "densely planted" seem inconsistent, they are. It cannot be assumed that if a primary macro (N, P, K) or a secondary macro (Ca, Mg, S) tests non-zero that the nutritional requirements of all macrophytes in the community are being satisfied. Getting enough to barely survive is not thriving. Undesirable consequences of too much light in a macronutrient limited condition will be the same as for the carbon limited condition.
Oligotrophy is defined as a low-nutrient trophic state and it must be recognized as potentially growth limiting. In an oligotrophic system NO3 < 10 ppm, and PO4 < 2 ppm. I achieved super-oligotrophy, especially when the SWCR DOEs were drastically increased; NO3 < 1 ppm, and PO4 < 0.5 ppm. These numbers were far too low. Super-oligotrophy is severely growth limiting, resulting in retarded production, and provides no opportunity for luxury uptake of N and P. Plants just stopped growing, oxygen production was significantly curtailed, and the periphyton exploded. No amount of light intensity reduction would compensate and the nuisance algae constantly threatened.

2) Last Monday I converted this system to low-mesotrophic. Immediately the SWCR was moderated, the exchanged water volume reduced by about 60%. I increased the fish food to near previous generosity. I manually dosed 50 mL KNO3 and I set the KNO3 solution auto-dose for 10 mL/day. I am also manually dosing KH2PO4 6 mL every other day to determine how to incorporate this supplement into the auto-dosing program if needed. In the intervening week there has been a remarkable change. Most impressive was the spontaneous and nearly instantaneous abatement of excessive algae of all kinds on the plant leaves. Plant growth is now noticeable, with improved color, and oxygen production is up. Mesotrophy is defined as an intermediate trophic state wherein 10 ppm < NO3 < 30 ppm, and 2 ppm < PO4 < 5 ppm. For our purposes here I define low-mesotrophy by 10 -15 ppm NO3, and 2.5 - 4 ppm PO4. These values are not growth limiting, or at least it may be said that they are more favorable to success with plants than is super-oligotrophy.

3) My quest for a low-nutrient environment was spurred by perception of a problem I did not actually have. In my attempt to drive DOM lower I practically shut down the feature of this jungle of which I was most proud to achieve - accelerated carbon fixation, vigorous production rate, and consistently high oxygen saturation. No improvement to the environment by aggressive removal of DOM comes close to the deterioration caused by starvation of the plants that comes from this. The experiment proves to my satisfaction that planted aquariums should be maintained as mesotrophic environments, and that exact resolution of macronutrient concentrations is superfluous.

4) The decrease in water change volume results in lower per diem chemistry maintenance doses, in this case a significant economic improvement as well as a much appreciated simplification of the schedule.
 

Paul G

Active member
Today's numbers

pH: 6.8
ORP: 531 mV
TDS: 330 ppm
NO3: 9 ppm
PO4: 2 ppm
K: 40 ppm
Fe: 0.34 ppm
dKH: 7.1
dGH: 3.8
Ca: 15.2 ppm
Mg: 7.3 ppm
Ca/Mg: 2.1/1
 

Paul G

Active member
Today's numbers

pH: 6.8
ORP: 525 mV
TDS: 320 ppm
NO3: 13 ppm
PO4: 3 ppm
K: 40 ppm
Fe: 0.22 ppm
dKH: 6.7
dGH: 3.4
Ca: 16.0 ppm
Mg: 4.9 ppm
Ca/Mg: 3.3/1

Over the last six days, the hardness numbers have stabilized to these numbers. The 200 grams aragonite HRR appears to be about right for the current LOOP1R flow rate. The macronutrients have gradually risen into mesotrophy; hereon supplement dosing will be decreased to level off these values.
 
Top