This talk presented an approach to fountain care that is preventative, focusing on maintaining an ideal water chemistry to prolong the life of fountains and associated mechanical systems, plumbing and artwork. Krueger presented a process for treatments to fountains, particularly when biogrowth is observed. Prior to treating water chemistry, Krueger recommended draining the water and mechanically cleaning the elements with a surfactant and clean water, taking care to rinse thoroughly.
Fountains must then be re-filled and if using a municipal water source it is likely that minerals and organic matter must be addressed, while a distilled water source may require addition of minerals. Krueger explained the concept of water saturation, and that unsaturated (soft) and supersaturated (hard) water both create problems either with leaching or precipitates. Water saturated of minerals is ideal, and pH and water temperature both affect saturation as well. Krueger recommended the Taylor Brand test kit, which is available at commercial pool/spa supply stores, to assist with balancing and monitoring water chemistry.
Regarding biogrowth, he explained that additives such as silver/copper, chlorine and quaternary ammonia all can effectively control growth but can cause issues such as staining, deterioration of mechanical systems and water foaming. Poly-quats act as blocking agents in swimming pools and ponds, and Krueger recommended its use for controlling bacteria and fungi. Filters help maintain water chemistry and control biogrowth by limiting nutrients available in water. Krueger explained that oligotropic water is ideal (trace amounts of minerals Ni, Zn and Cu), and that controlling phosphate levels is recommended to limit biogrowth.
A series of steps were presented for checking levels and making alterations to the water chemistry. 1- Make visual observations, as the presence of a slippery surface can indicate the beginning of growth. 2- Test water (phosphate levels, temperature, and level of polyquats which requires a special kit). If high levels of phosphates are found then it can be remedied by draining some water and refilling it (if under 125ppm) or using a chelating agent and then backwashing (if over 125ppm). To adjust alkalinity, sodium bicarbonate can be added in small quantities and checked every 24 hours. Then total dissolved solids (hardness) should be tested and followed by checking calcium carbonate hardness, keeping in mind that calcium hypochlorite should not be added to adjust, rather by draining some water and adding new. Finally the overall saturation should be checked. 3- Inspect mechanical equipment. Filters should be inspected per manufacturer’s instructions. Krueger shared that he is researching the practice of adding barley straw in water, as there is published data that supports or disputes its ability to eliminate algae by releasing peroxides in the water.
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AIC Blog Archives: Conservators Converse
Former Blog of the American Institute for Conservation