5.04.2025 Greenhouse pond?

 ~o~

  Saturday 5th 39F/4C [7.30] Bright but rather cloudy. Increasingly breezy from the north east. The clouds seem to be moving quite quickly from the north Two more days of sunshine promised but at lower temperatures. Today might reach nearly 9C/48F. 

 Up at 6.15 after another quiet night. Lower back pain may be the result of a day wasted on the computer. No immediate plans beyond my morning walk. 

 8.40 41F/5C. Overcast! Well past time for a walk. 

 9.00 And back again. I only walked a few hundred meters along the road before turning back. The wind made it feel very chilly. Not nice at all.

 Moved here from yesterday's post: 

 The Chemo/Cemo colour options [and blue.] These are a smaller model but images of the 1500l are hard to find online. The image below of the grey container is the correct model but gives little sense of the proportions.

 I am looking at options to house a raised, rectangular goldfish pond. Using a green [or grey?] GRP, industrial storage container out in the greenhouse. The outside of this container could be covered in timber boards. To make it look more attractive. Though the tanks themselves are smooth and cosmetically acceptable in their own right. Shall we say more purposeful than deliberate greenhouse furniture.

 A level, plywood base would not raise it any more than necessary. The base would need to be strong and load spreading. Only high enough to allow a seated person to easily admire the contents. The container could even be sunk into the brick floor. If I thought it was useful. I laid sand under the bricks.

I do not have any reason [at all] to be out in the greenhouse at present. Which is a bit of waste. The greenhouse's considerable volume could house many plants. Though probably only the hardiest of cacti at present!

 The limitation of container size is the size of access to the greenhouse. The greenhouse's double, open door width is 85cm. The range of containers I am admiring are [by happy coincidence] 81cm high in a variety of increasing volumes. So I could easily slide quite a large container on its side. Through the open greenhouse doors. 

 The tapered walls and projecting rim would cause it to lean. I would use suitable battens, boards and scrap plywood on the ground outside and on greenhouse floor. Which will protect the container's finish. While making it upright while siding on its edge. The dry weight of the larger 1500 liter containers is just under 50kg. Manageable, but a bit lumpy for one old fart to move around on his own. One mistake and the greenhouse could become an expensive repair job!

 The next size limit is how much I am willing to allow the tank to project. Out into the greenhouse area from the glass, front wall. With some nominal clearance, of course.

 The kitchen end of the greenhouse is presently no man's land. This is due to several years of untouched clutter. Mostly my wife's gardening and cleaning stuff.  If that was cleared there would be lots of room. I rarely need to go in and out of the doors at that end of the greenhouse anyway. Only the doors at the opposite drive end are ever used. For bringing in logs using a wheelbarrow.

 The cost of these containers is a fraction of any glass, fish tank of remotely the same length or volume. Goldfish tend to grow rapidly in suitable conditions. They are already stretching the acceptable limits in the secondhand aquarium I bought. 100x50x50cm and 250liters. Two tiny fish have grown to almost half the 50cm dimensions. Well, not quite, but appearances aren't that far off. 

 The minimum size of container I would consider is 700 liters. With 1100 and 1500 liter models readily available at the same height but increasing cost. Depending on how much floor space I am willing to sacrifice out in the greenhouse.  

 The 1500 liter container is my favourite choice at 182x139x81cm measured externally. That would be six times larger than the indoor aquarium. The greenhouse is 2.6m deep between the greenhouse front and the house walls. 260-139=121cm. Plenty of room to move past the tank. Which will be quite low at about 85cm to the rim. Just below waist height. I'll try not to fall in! At least not when the water is cold.

 Reasons to go indoors: Any outdoor pond risks becoming the prey of the many herons in the area. I have already suffered from the attentions of a heron's pointy beak. While rescuing it from a protective net on the outdoor pond. If Danish winters ever return to normal. Then the outdoor pond would be covered in thick snow or ice for weeks. 

 Not to mention the constant rain of leaves. Falling from the surrounding and overhanging trees. The fish were never visible before they ended up in a heron's tummy. Thanks also to the floating pond weed. While an indoor pond would allow me to watch their antics. Perhaps in slightly greater numbers than the indoor aquarium.

 The downside is that I will not get the side view of the fish. Afforded by an inset window or glass aquarium. However, the much greater width and length of the pond. Will allow a clear view as the colourful fish approach the surface. I do not much like black ponds. So will not use rubber or plastic sheeting to make my own indoor pond from plywood. A preformed container will also avoid ugly folds in the rubber membrane. 

 The grey colour option is beginning to seem far more sensible than my first choice of green. It will reflect more light than green. Making the fish easier to see under constantly changing light conditions. No doubt the inside surfaces will soon become green with algae if not cleaned regularly. Particularly in sunlight. The container is said to be smooth inside and out for easy cleaning.

 Meanwhile, there are clear plastic cylinders widely available. Which allow fish to swim above the pond surface. The cylinder remains constantly filled with water by excluding air during filling. See image above. Such a feature might make for an interesting addition. 

 One vital detail I haven't yet mentioned is water's ability to store heat. Such a large volume of water [1500 liters or 400 gallons] will help to ameliorate the rapid temperature changes. Which are currently enjoyed by the greenhouse. The water will absorb solar warmth during the day and only slowly release it overnight. This should help to reduce the soaring, daytime temperatures. While preventing rapid cooling overnight. 

 It is common practice to stack oil drums full of water in solar greenhouses. To act as heat sinks. This can moderate temperature swings. Enough to allow plants to survive and even grow well. Where outside temperatures are totally unsuitable for plant growth. In desert conditions or old, northerly climates.

 The recent run of sunny weather has resulted in afternoon greenhouse temperatures exceeding 110F/43C! This is in spring. With only quite modest outside temperatures. Around 50F/10C or slightly higher. The greenhouse temperature extremes are entirely due to solar gain and a lack of heat sinks. A solar oven by any other name. 

 I laid a herringbone pattern of bricks on the floor when I built the lean-to greenhouse. This helps to absorb some heat but the sun only reaches it in summer. The southern house wall is white painted brick. With a few, rather small windows and a glazed door. Not much heat sinking there.

 I should soon be adding the doubled shade nets to the greenhouse roof.  Because they reduce the sun's heat from entering the greenhouse. Once it has passed through the glass the sun's heat is very difficult to control. I have both double end doors open during the day in summer. For any through draft to help vent some of the heat. With fine weldmesh security and insect blocking netting over the wide open doors. Plus the commercial quality shade netting on the roof and front wall of the greenhouse. 

 It is obvious that I do not want stray animals or insects entering the warm greenhouse. Deer are regular visitors and wander everywhere. Then there are numerous domestic cats and strays. Rodents would enjoy the cosy conditions too. I have seen a tiny mouse running into the corner out there. To promptly disappear into the floor. 

 10.20 43F/6C. It is brightening up as the cloud thins. I feel a modest ride would be in order. Somewhere around 25-30km will take me to several places I want to visit.   

 13.00 46F/7.8C. Sunny. Back from a 37km ride to the shops. There was a horribly cold wind throughout. With my eyes streaming despite the wraparound sunglasses. There was no protection for my nose streaming. I was just beginning to feel saddle discomfort towards the end of the ride. Am I having fun yet? 

 The greenhouse is at 100F/38C again and all internal doors door have been opened. It reached 68F/20C in the room.

 8.15 Dinner was mackerel in tomato sauce on toast. Followed by a glass of the excellent, locally produced apple juice. Kindly provided by my English friend. The room has already dropped to 64F/18C. I had better light the stove.

 

 ~o~