Water plant maintenance

 The weather is glorious today, so of course, I cycled to the greenhouse.

Student T... was given instructions from B... that I should clean the water plant reservoirs in room C2. In preparation for the job I tried without success to decouple the hose between the upper and lower reservoirs. I don’t think it is possible without cutting the hoses, so I just let them dangle while I drained and lifted the large upper reservoir/tank - I estimate it measures 4 x 10 feet, and 1.5 feet deep (about 150 gallons). The lower reservoir is 40 gallons, and holds R/O water which is pumped to the upper chamber constantly to provide waterflow and aeration to the plants. Both chambers needed emptying and cleaning.

I first removed the plants from the upper chamber, setting the small plants on a cart, and the large plants on the floor. I opened the valve of the upper chamber to allow the dirty water to flow onto the floor and into the nearby floor drain.  I then tilted the now-empty large chamber up on its side where it rested against the tall. I used the hose and tempered tap water to blast the dirty surfaces, then scrubbed them with a scour sponge. There were many snails, which I had to sacrifice, although many more remained attached to the plant pots and their roots - so I didn’t feel too badly about losing some of them in the cleaning process. I reset the tray onto its base, and used R/O water to refill it.

Next, I emptied the lower chamber by tipping it on its side to drain the dirty water onto the floor. As with the upper chamber, I used tempered water to scrub and rinse the surfaces. After returning the lower chamber to its position, I replaced the hoses and allowed the upper chamber to begin draining into the lower chamber through the hoses. I restarted the circulating pump, to send water from the lower reservoir back to the upper reservoir, thereby completing the circulation loop.

Then, the plants were hosed down to clean the roots and outer surfaces of the pots before they were placed back in the upper reservoir. I trimmed out dead leaves as I returned the pots to the water.

After cleaning the reservoirs B had a small shrub (Illicium floridanum) to be repotted. I used #1 mix, pre-wetted, to line the bottom of the new pot to prevent the soil from falling out of the drainage holes. This is a trick I overheard Curator J suggest to someone else. It works!