I have changed the dosing interval to 5 days. I have ordered another 6-pack of AC and am extending the trial.
Day 33: Saturday 12/23/23
Added first 16 oz AC at 06:00. ORP dropped 88 mV, DO dropped 1.2 ppm, pH dropped 0.1. Second 16 oz AC added at 10:15 with another sudden drop in redox. Lights out until tomorrow AM. All parameters recovered by 12:00.
Day 34: Sunday 12/24/23
Returned to regular schedules. No abnormalities or adverse effects in evidence.
Whatever the plants like, do that.
I order direct from Green Water Labs on-line.
The pH notch is definite but transient. If you are monitoring pH, the effect of the dose will be clearly noticeable but the water chemistry will recover its previous state probably within the hour. You could add buffer when dosing AC, but once the pH notch disappears your KH will have been raised by the buffer you added. In my system, the pH did not drop more than 0.1 and the notch width was never more than an hour. I do have a lot of -2 CO3 buffer normally because I keep my KH at around 6 d (107 ppm). I watched the fish closely and observed no ill effects. As water chemistry may vary between tanks, I should not predict what you will encounter. If you remain within GWL's dosing instructions I doubt the pH notch represents danger. How much buffer of the kind you use would be necessary to erase the pH notch must be determined experimentally, and I would not undertake that work unless I was convinced it was necessary. Consider also whether that neutralizing dose impacts efficacy of the additive. I don't know this because I don't know much about this product anyway, but the implications are important.
More significant is the sudden increase in chemical oxygen demand (COD). Judging by redox (ORP) this transient goes deeper and wider. The redox drops like a rock and O2 can fall off 2 ppm, possibly more for a short time. I prevent this in my tank because I have a large aeration system that turns on automatically if O2 falls below 6.5 ppm. So I don't really know if depression of DO is actually more severe than this. I suggest vigorous aeration be used for the first hour at least of the treatment.
Algae Control is a highly reduced organic or a mixture of such organics in aqueous solution. I can't test for it directly, but just looking at the pH, DO, and ORP traces the stuff virtually disappears into the system after an hour or two. It is not stable, or designed to be stable, in sunny, aerobic, biologically active environments. It does it's job (whatever that is) by being used up. The large oxidation capacity of a planted aquarium will neutralize a reduced organic by measures. There being an allochthonous source only for it, it must be continually added to maintain a specific concentration - if that is what is wanted in terms of final solutions.
Whatever the plants like, do that.
Day 38: Thursday 12/28/23
Added first 16 oz AC at 07:30. ORP dropped 100 mV, DO dropped 1 ppm, pH dropped 0.1. Added second 16 oz AC at 09:05. Lights out until tomorrow AM.
Whatever the plants like, do that.
Day 39: Friday 12/29/23
Return to regular schedules. No abnormalities or adverse effects in evidence.
Whatever the plants like, do that.
Day 43: Tuesday 01/02/24
First 16 oz bottle 07:46, second 16 oz bottle 08:16. The expected COD spike with the usual effects to ORP and DO, and small notch in pH. Lights out until tomorrow AM.
Whatever the plants like, do that.
Day 44: Wednesday 01/03/24
Return to regular schedules. No abnormalities or adverse effects in evidence.
Whatever the plants like, do that.
Day 48: Sunday 01/07/24
The first 16 oz bottle at 07:30, second 16 oz bottle at 08:00. The expected COD spike with the usual effects to ORP and DO, and a notch down 1.0 in the pH. Lights out until tomorrow AM.
Whatever the plants like, do that.
errata: above post pH down 0.1, not 1.0. The effect to pH has not been observed in this trial to be as drastic as anything approaching a full 1.0.
Whatever the plants like, do that.
Day 49:Monday 01/08/24
Return to regular schedules. No abnormalities or adverse effects in evidence.
Whatever the plants like, do that.
Day 51: Wednesday 01/10/24
I have another 6-pack of AC and am extending this trial a bit further. Today I changed out the mechanical filters and did a 16 gallon "big gulp" water change. Also removed the Java fern temporarily so all the back and sides could be accessed with the algae scrapers.
One 16 oz AC added at 14:50. Second 16 oz AC added at 18:00. No blackout.
Whatever the plants like, do that.
Day 52: Thursday 01/11/24
No abnormalities or adverse effects in evidence.
Whatever the plants like, do that.
Day 56: Tuesday 01/16/24
First 16 oz AC added 07:30. Second 16 oz added 08:27. The usual pH and COD transients. No blackout.
Whatever the plants like, do that.
Day 57: Wednesday 01/17/24
No abnormalities or adverse effects in evidence.
For the last week, the lights have been turned up just slightly. The Hygrophila difformis survived just fine at the lower light levels, but was very slow to grow. Same for the sworplants which were uprooted and replanted recently. I am not taking PAR measurements but am observing closely. The minimum light consistent with slow but positive growth is the goal.
Whatever the plants like, do that.
Day 61: Sunday 01/21/24
PRELIMINARY OBSERVATIONS AND THE NEXT STEPS
I believe this product has an effect on algae. At this point in the trial results are mixed. The general impression is favorable overall, but there are still some unsightly dark green spots and patches on older swordplant and crypt leaves that appear not to be attenuated.
DARK FILMY GROWTH: Earlier on I had pruned out older growth that looked hopeless, leaving some of these leaves where I can watch progress. If I am going to continue dosing AC, it will be resumption of the trial to pin down a final judgement after I have done an enthusiastic physical removal of everything that has not shown any improvement after the treatment so far. As discussed earlier, the big crypts seem to tolerate having the upper sides of their leaves infested. They shed older leaves and the plants continue to grow. It looks to me like many of these leaves show significant thinning of the infestation, but it is far from being eradicated. The new crypt sprouts popping up everywhere are relatively clear, but evidently not immune. The black/green film keeps trying to spread and is especially visible on the new, but now lower parts, of the water wisteria. I find this discouraging because I expected that after all the treatment with AC this blight would show some sign of attenuation by now.
ALL OTHER ALGAE: There are no other types of algae to be seen anywhere. No BBA or any kind of "fuzzy" or beard algae, even small tufts that tend to erupt where the current is favorable, as they sometimes do. There are no filamentous hair greens or blue-greens. Something unexpected is the exceptional clarity of the water which I attribute to suppression of all planktonic forms and their grazer populations. A thorough scraping of the glass, including sides and back from rim to gravel-line, is done weekly. Algae is now very slow to reappear on these surfaces this far into the trial, even though I am trying to raise the illumination.
I have just this one aquarium, not counting the holding/quarantine 20 Long, so I maintain this as the show tank it is meant to be. As a result of this, I have been doing other things in the fight against algae besides dosing AC. It is essential to identify and correct causation in the first place, so I am altering the lighting, implementing blackouts, decreasing all sources of nutrient (scrupulous feeding and routine detritus removal), and doing frequent mechanical and biological filter maintenance, with attendant water changes, all the while I have been conducting this trial. This increases the difficulty of analyzing the efficacy of AC alone because I am deliberately altering more than one variable at a time. I fully appreciate that this confounds the interpretations of results and thus compromises the experiment to some extent, but it must be recognized that all feasible steps must be taken to secure a satisfactory outcome without risking further degradation. Technically, this is just adhering to the stringent standards of practice which have been obligatory all along; get at the root of it and solve the real problem, and don't rely wholly on alleviating the symptoms by "treatment" of the water column with algicides and algistats.
Two important modifications to the system were made at the beginning of the trial:
1) The gravel bed jets were turned on again, thus restoring the reverse-flow undergravel filter. This will have, certainly is having, an effect on the substrate that will probably take some time to manifest and then to fully evaluate. This is an inert gravel bed (apart from existing mulm) and the scheme of nutrient delivery is becoming increasingly hydroponic. This is a topic for a later time, but suffice it to say there have been no undesirable effects of any kind respecting health of fish and rooted plants - thus far. Implications to the algae problem are uncertain for now.
2) The hardness profile was flipped to make the GH and KH commensurable, with GH leading (i.e. dKH < dGH). This significantly reduces the concentration of bicarbonate, which all algae are readily able to assimilate more efficiently than can macrophytes.* Bicarbonate is a source of carbon for algae; a correlation of alkalinity and algal population growth should be expected. I am certain there is something important about the "nuisance algae" problem to be learned here.
I have returned to the GWL web-site and again studied all the information they have there about AC. There is revealed in the FAQ section (and only there) that the mode of action of AC is disruption of "algae enzymes necessary for photosynthesis." The active ingredient insinuates itself into the metabolic pathway and interferes with vital functions. This defines AC as a true algicide though details are not discussed.
Given the encouraging results, I am inclined to continue this trial further. These remarks will be continued in following posts.
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*Sigee, David C. 2005. Freshwater Microbiology. Wiley. See sub-chapter 4.8.
Whatever the plants like, do that.
Day 64: Wednesday 01/24/24
Did 24% water change, changed and cleaned filters and intakes. First 16 oz AC put in at 11:31, second 16 oz put in at 13:03. Usual pH and COD transients. No blackout. SWCR suspended for 24 hours.
I now have the last 6-pack (3 more treatments), and the trial will be concluded by mid-February. A 32 oz dose of AC has been used every 5 - 7 days beginning 11/20/23.
Whatever the plants like, do that.