if you are making your own nutes using individual chemicals, then yes you will want to test the pH initially. However once you have a recipe, you don't have to test. If you want to reuse nutrient solution in a to waste system, then yes you would have to test the pH. If you just drain the waste to say landscape plantings then no you would not test that. Hydro is usually done in an inert medium. However, as the u. of arizona quote above shows, non-inert media like sawdust can be used. I will agree that the line between hydro and conventional starts to be blurred by using non-inert ingredients. But I think that the intent of the nutes being used helps clarify that. If you are using nutes that don't require biological breakdown like nitrates it's closer to the hydro bright line. If you are using nutes like urea that do require breakdown and will work on the medium it's closer to the conventional bright line. there is definitely a continuum. Not every synthetic would be hydro. Urea and ammonium are going to require biological activity (yes you can use those in a recirculating hydro setup but the results are generally not great). Those are the most common synthetics used by commercial growers. Nitrate based hydro nutes are much more expensive. A lot of commercial growrrs also use composted bark for moisture retention. That combo is much more conventional than hydro. Those media breakdown quickly and they have to repot evey season. that last bit about organc and synthetic is just confused because of the erroneous vernacular use of 'organic'. Organic hydroponics are just nutrient solutions of immediately available nitrates from 'organic' sources. The whole semi thing cracks me up a bit. 20 years ago if you walked intoa hydro store you would find decorative cotainers for houseplants that were passive systems that look exactly like the semi containers. They were rightly called hydroponics. They were usually from Europe and they would be filled with hydroton or leca. Then along comes one orchid grower in the US that felt that people were afraid of the word hydroponic does the same thing and brands it semi-hydroponics and puts it on the web and poof, people start calling passive hydroponics, semi-hydroponics. Of course, all the people in Europe that are still doing the same thing are doing passive hydroponics. Books on hydroponic houseplants still refer to that system as hydroponcs. But that guy sure gets a lot of hits because he convinced people that semi-hydroponics is something different than what people have been doing for decades.

The method is not generally known in the hydroponics community, it is only an orchid thing, known by few outside the forums so googling won't get you far. I have been growing this way for nearly a decade and give lectures on it at orchid societies etc. It can be argued that if you let the pots go dry then you are not using the technique, and hence the name, but the orchids that need a rest are somewhat of an exception. In a greenhouse you can usually not give them a rest and still get somr flowers. This may be a bit dicy if growing in a house. The plant form and function is not radically different after being grown with the technique, so if you stop watering for the winter, or let the pot go dry through negligence in the summer the plant will not be harmed. In my experience with Den nobile species and hybrids it is the temperature drop that gets the flowers going, and lack of nitrogen that holds off new growth (A cold snap late in spring can bring on flowering of growing canes). Water is usually associated with nitrogen by releasing it from dry organic medium even if you are not fertilizing, so a dry pot means no nitrogen for the plant. The pellets don't hold on to/build up fertilizer salts the way organic medium does because they get flushed each week so it is not that big of a deal if they stay wet a little longer. The pellets hold a great deal of inner water so letting the pot go dry is not really providing the plant with a dry pot. If you flush the pot with fresh water (you can do this a second time in a couple of days if you want to feel better about it) and just let the plant sit it will keep its leaves for a while and photosynthesize until after new years, gaining energy for flowering. When the pot hits critical dryness leaves will start to drop and then you should get flowers on time. The trick is to get the mature canes as much light as possible while its leaves are still on to support production of more flowers. I never got the hang of Den kingianum. They seem to need real stress to bloom, and minw were always in the wrong place and so got watered and fertilized way enough to stop them from blooming. The year I transfered them they bloomend well even though I fertilized them so I'm assuming it was the stress that year.

I do not think you will be successful rooting a strep leaf in water - it will probably rot. You can try to root it in sphagnum moss, perlite or vermiculite - - or just a plain Cornell mix. When the babies develop a root system - you can try to move them to the hydroton - or whatever media you plan to use. You probably need to dome it it first - and open when it will start growing. Streps have high requirements of an air access to the roots - so potentially semi-hydro is a good approach. You can try to grow them in a sheet moss - it will also provide a high evaporation and cooling. I think one of the gardenweb members double potted her streps in a summer - put the soil growing streps with pots in a larger clay pots with wet sphagnum in a spase between the plastic and clay. Porous clay provided the chill.

The hyper heat heat pump can make sense to cool an area with difficult access for ducts. Does the basement fit that description? It will cost you more to heat it with a heat pump than with natural gas. What are the aims of zoning, saving energy or comfort? If the former, you are probably barking up the wrong tree. If you have a well-sealed, well-insulated home, your heat transfer rates between rooms/floors will be much faster than out of the structure. Zoning can be difficult to accomplish, but not impossible. With old-school high mass boilers, it was not so difficult, but a modern, low-mass boiler, if sized to heat a large area, will be shutting off frequently. The same may be true for furnaces, but I am not as familiar with that issue. I've seen you write boilers and furnaces, which are you looking for? You can do forced air heat with hydro coils powered by a boiler, or with a furnace. With a hydro coil, you might be able to heat the bonus room but you'd still need a way to cool it. Cost calculations would tell you if it is worth it to install separate cooling and heating systems there. What are you planning on doing in the basement? Is is going to be just one, open area? I'd consider hiring an energy rater to help you plan and set milestones for the builder. They can help you choose your mechanical systems appropriately. They can do blower door tests to make sure that the house is air-sealed and insulated properly. Where are you located? It can make a big difference in figuring out what kinds of equipment to install if you have to heat a lot vs. cool a lot or both. Humidity is an issue too.