• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Algaecides (not Glutaraldehyde)

This means it is safe to dose one baby aspirin or 89 gm daily to carp, and probably also OK to dose full strength or 350 gm non daily.
I honestly don't know mate. Personally I'd be reluctant to dose any levels simply because there's mixed information out there as to the toxity of Salicylic acid/Acetylsalicylic and fish.

I think there definitely needs to be some hobbyist type experiments done to work out if a sweet spot can be found that kills off algae and has no negative effects on plants, I just think this should be done initially without potentially harming our livestock.

On a related note I found this information that suggests in not to high doses salicylic acid can also be harmful to plants.

Any other information on results incl. tables​

At 60 and 120 mg/l of salicylic acid reduced the final leaf number, the dry weight and the chlorophyll contents of L. minor (see table 1 below).
Chlorophyll contents in Lemna tissues and in water are negatively correlated.
The highest dose caused a rapid yellowing of leaves.

Table 1: Effect of salicylic acid on the growth, biomass and chlorophyll contents of L. minor. Values expressed as percentage of controls after 7 days exposure.
Nominal concentration of salicylic acid (mg/L)
No. of leaves
biomass (dry weight)
Chlorophyll content
Tissue
water
15
94*​
100​
102​
160​
30
96​
90​
100​
180​
60
90*​
75*​
75*​
220*​
120
20*​
15*​
3*​

* data significantly different from controls.
It was suggested in the article that additional toxic effect on the plants are likely at a pH below 5.
table 2 : pH values at different concentrations in salicylic acid and sodium salicylate
concentration in mg/L 0153060 120
pH in salicylic acid solution6.746.606.425.923.66
pH in sodium salicylate solution6.896.927.007.147.38

Applicant's summary and conclusion​

Validity criteria fulfilled:not specifiedRemarks:not applicable no guideline followed and not enough data to assess validity criteriaConclusions:In the conditions tested, salicylic acid showed a slight effect on growth of the aquatic plant Lemna minor.
However, complementary results with sodium salicylate which does not lower the pH as much as salicylic acid showed no toxicity directly linked to the substance. This toxicity of salicylic acid therefore might be due to a physical effect (acid).Executive summary:
In a 7 days acute toxicity test, single-leaf plants of Lemna minor were exposed to salicylic acid at nominal concentrations of 0, 15, 30, 60 and 120 mg/L.

The study did not followed a guideline but seems to be scientifically well performed.

Growth inhibition was recorded via biopmass parameters (dry weight, number of leaves and chlorophyll content inside tissues and in water).

These parameters and were significantly different from control between 60 and 120 mg/L, therefore the The 7 -d EC50 is between 60 and 120 mg/L of salicylic acid.

Yellowing was only observed at the highest concentration tested.



In the test conditions, salicylic acid is considered as harmful to algae according to Directive 67/548/EEC criteria.

Authors also indicate that salicylic acid and sodium salicylate are of a lower toxicity to aquatic plants in a concentration range up to 50 mg per liter and could be ranked into class 1 of chemicals with a low hazard potential (Geyer et al., 1985).

Considering the effect on solution pH of salicylic acid it is therefore relevant to consider that the toxic effect observed in this study is related to a physical effect (acid) and as suggested by authors, to consider salicylic acid as a substance with low hazard potential.



The authors have not followed any guideline and no information is given for GLP, analytical monitoring of the substance, purity of the substance, test conditions. But, it seems that the method mainly follows OECD guidelines with deviations (no reference substances testing, four concentrations tested). And analysis of the results is reliable by considering the potential pH effect on the toxicity.

Therefore this toxicity study is considered as reliable with restrictions.
 
I don't have full access to the paper so haven't read their test procedures, but have requested it and will post here if I get it.
The request came through so being good to my word here's the full study text from post #59.
 

Attachments

  • asprin.pdf
    713.3 KB · Views: 167
So it looks like as long as your dosing less than 15mg/L of Salycilic then there’s little to no deleterious effect on the higher order plants and this dosage is a magnitude away from chronic levels used to evidence biological changes in the target fish species from that study.

Question is at what mg/L level is actually required to have a desired effect on Algae.

:)
 
Question is at what mg/L level is actually required to have a desired effect on
From what little research I've done it looks likely to be around 100mg/L.
Like most things in our hobby hard facts are hard to come by. My latest early morning search threw this up from the Sigma - aldrich safety data sheet for Acetylsalicylic Acid.

Screenshot_20220531-204243_Drive.jpg
 

Attachments

  • a5376.pdf
    363.6 KB · Views: 154
I may be a little bit late to the party
Me too. Found this:
Algaway: Biocidal active substance: Salicylic acid 0.01 g/L Dose 35ml per liter for four weeks. Dose can be continued if algae still present. Also promotes healthy plant growth. Also a caution about effects on other critters.
Bought my salicylic acid from ebay for peanuts. You do need a half way decent balance and have a mind set for ratios/serial dilution. I tend to base my solutions on 100ml of 'stuff' to a tank of guestimated net volume of 300L. It just makes weighing out easier.
Appears to promote root growth in higher plants. No obvious effect on my fish , snails and amano shrimp. Snails never do well because I use CO2.
 
Me too. Found this:
Algaway: Biocidal active substance: Salicylic acid 0.01 g/L Dose 35ml per liter for four weeks. Dose can be continued if algae still present. Also promotes healthy plant growth. Also a caution about effects on other critters.
Bought my salicylic acid from ebay for peanuts. You do need a half way decent balance and have a mind set for ratios/serial dilution. I tend to base my solutions on 100ml of 'stuff' to a tank of guestimated net volume of 300L. It just makes weighing out easier.
Appears to promote root growth in higher plants. No obvious effect on my fish , snails and amano shrimp. Snails never do well because I use CO2.
I ended up making a bit of a compilation thread about it :thumbup:

This is what Mineral Nutrition of Higher Plants has to say about Salicylic Acid by the way (I stumbled across it the other day)
Salicylic acid is synthesized from phenylalanine (Crozier et al., 2000) and is present in all plant tissues. Increasing salicylic acid concentration slows leaf senescence and induces flowering, probably by reducing the rate of ET synthesis. The synthesis of salicylic acid is also associated with local hypersensitive response and the induction of systemic resistance to the spread of some fungal, bacterial and viral diseases (Crozier et al., 2000; Bari and Jones, 2009).
From another section about Potassium:
They show that K deficiency induces not only the expression of high-affinity K+ transporters and enhances root-hair elongation mediated by ethylene and ROS, but also activates signalling cascades similar to drought, wounding and biotic stresses involving phytohormones and jasmonic and salicylic acids (Ashley et al., 2006; Amtmann et al., 2008); the latter two being important for pathogen resistance. Thus a higher stress resistance of K-deficient plants could have been expected.

I would like to look further into the sources, but it will have to be later :geek:
 
James Wong, the botanist/horticulturalist recommends aspirin as a foliar feed. Most of his content is in his books rather than web articles but here is an old tweet from James. Fine for plants I guess but not sure our fauna would actively choose to swim around in a weak solution of aspirin, let alone all the toxins mentioned earlier in this thread. Not sure how this counts as ethical husbandry of live animals.

Yes! Soluble aspirin is chemically very similar to a plant growth regulator called salicylic acid.Spraying on a dilute solution now basically turns on the genes that express their defence system.It creates more resilient plants & even better-flavoured, more nutritious fruit.
 
Back
Top