algicides Substances used to kill algae in the aquarium. bleach Not recommended peroxide Spot treatments only excel Plant growth enhancer and algaecide Some good some bad. I had a little to do with the popularization of the use of bleach and peroxide because of articles I wrote about them in TFH. I wish I never had. Those things are nothing but trouble. ammonia The most dangerous chemical naturally found in aquaria toxicity chlorine Ascorbic acid is the safest and cheapest way to neutralize chlorine and chloramine. refs One gram of ascorbic acid will neutralize 1 milligram per liter of chlorine per 100 gallons of water. The reaction is very fast. The chemical reaction (Tikkanen and others 2001) of ascorbic acid with chlorine is shown below: C5H5O5CH2OH + HOCL → C5H3O5CH2OH + HCl + H2O Ascorbic acid + Hypochlorous acid → Dehydroascorbic acid + Hydrochloric acid + water Approximately 2.5 parts of ascorbic acid are required for neutralizing 1 part chlorine. Since ascorbic acid is weakly acidic, the pH of the treated water may decrease slightly in low alkaline waters. - Dustin Carver See also: Using Vitamin C To Neutralize Chlorine in Water Systems The intended audience is sanitary engineers and operators of water and wastewater systems. Brenda Land, Sanitary Engineer, Project Leader https://www.fs.fed.us/t-d/pubs/html/05231301/05231301.html cyanide Cyanide occurring in freshwater "Under aerobic conditions, microbial activity can degrade cyanide to ammonia, which then oxidizes to nitrate. This process has been shown effective with cyanide concentrations of up to 200 parts per million. Although biodegradation also occurs under anaerobic conditions, cyanide concentrations greater than 2 parts per million are toxic to these microorganisms." "Algae and macrophytes can tolerate much higher environmental concentrations of free cyanide than fish and invertebrates, and do not exhibit adverse effects until 160 micrograms per liter or more. Aquatic plants are unaffected by cyanide at concentrations that are lethal to most species of freshwater fish and invertebrates." ferts Aquatic plant fertilizers chart Plant nutrient deficiency symptoms recipes Fertilizer recipes and concentrations Over a period of about 20 years or so, mostly on the net, liquid aquarium fertilizer changed from either mostly useless and spooky things to complete and well understood regimen of the optimum nutrients. The formulas are dead simple and the ingredients can be bought in any decent drug store or grocery store and hardware store. hardness Water hardness rainwater Creemore Ontario has the hardest water I've seen in the world - 1200 ppm carbonate hardness in the water. Fill an aquarium with it and by morning fine layer of chalk dust will have settled out on the bottom. Life exists in pure rainwater pools, and species that have adapted to this are a special challenge in the aquaria.

history History of aquarium chemistry fertilizers History of Aquarium Fertilization synthsea History of Synthetic Seawater The history and evolution of chemistry as used in aquaria, from it origins to the present. nitrates Hobby test kits are not accurate, and nitrates may not be as harmful as people believe. My nitrate test bottles were down to probably a few tests left so I ordered a new Kit and compared the result out of curiosity. New: 10-20 ppm, Old: 40-80 ppm. I only had the old kit for about a year." ph Acidity and alkalinity schreckstoff "Fright" substance selenium