How it looks from my perspective: If the decision to reuse container soils is an economic one, who can disagree with the decision? If you aren't concerned about expense and are willing to go to some minimal extra effort to build a good soil, that is what I would elect to do. Here's why: Container gardeners need to direct primary focus to insuring that the soil they are using will remain able to provide adequate air to roots for the expected life of the planting. Along with the ability of the soil to hold ample air, comes good gas exchange and drainage for rootage. All the other major cultural variables affecting growth are easily manipulated. Water, nutrients, sunlight, and to some degree, temperature can all be controlled easily. Aeration cannot and its consideration is as important as water and light to plant vitality. The breakdown or collapse of soil structure occurs at an exponential rate. If we imagine the usable life of a peat based container soil from a bag, it deteriorates from a reasonably good soil when fresh to unusable after 2 years. It's not unreasonable to expect the soil to lose at least 20-25% of its air holding ability by the end of the first growing season. In the first half of the second growing season, it will lose about another 25% of its air holding ability and in the second half of the second year, near total collapse is likely as the remaining 50% is lost. Though this is an example of an imaginary soil, it is very close to what actually occurs. Another way of saying it is: Even though a soil might be performing acceptably at the end of the first growing season, you should expect a rapidly accelerating collapse in the subsequent year. So, if you use a soil for 1 year and mix it 50/50 with a fresh, similar soil, 50% of the soil will have totally collapsed by the end of the growing season, and the other 50% will have lost about 25% of its ability to hold air. If a soil is not holding enough air, it's holding too much water. Water and air retention vary inversely in soils and when one increases, the other decreases. When soils hold too much water, you have to hope that the plant will use enough water or that enough water evaporates to prevent root rot issues and even minor cases of over-potting can mean terminal misfortune. At risk, I speak out often against the use of compost in container soils. It supplies nearly nothing in nutrients and clogs the soil macro-pores container gardeners should covet. Containers are not gardens and much of what works in the garden can cause difficulties in containers. Additional possible considerations are carry-over of fungal spores, the possibility/probability of insects in various stages (eggs, larvae, etc) and carbonate precipitates from your watering water. A slow soil will also have accumulated fertilizer salts and possibly insecticides that you may have applied and forgotten about last season. I suggest that container soils be turned into the compost pile or garden and fresh soil used in its place unless monetary considerations prohibit. Al

The prefilter I use is similar to an Adam's filter. It has helped to keep my pump from getting clogged and needing the daily maintenance it needed when I first bought the house (and pond). But what really has made the difference for me is getting into the pond in the spring to clean it out by hand, scooping out all the muck. letting it settle, then coming back and doing it again, and then a third time. This included pulling out (for good!) all the hundreds of small rocks that the previous owner had on the bottom where the mulm would sit on top and inbetween. Now because I started with a sparkling clean pond, the prefilter catches the little thats left or it settles to the bottom around the prefilter. I just go out daily with a fish net and scoop the area on the bottom where I start to see a little mulm gathering. This takes about 1 minute every day. Because I maintain it daily, theres so little mulm in the pond, my prefilter catches easily whats there, and next to nothing goes to my skippy. But last year, when I didn't do such a great job at cleaning the pond in the spring, my skippy ended up with about 4 inches of muck by the end of the season. I won't allow that to happen again. Its the spring cleaning that leads to the entire summer of pond cleanliness for me.

hawkiefriend, What are you pumping to? Do you have a filter set up outside of your pond that you are pumping to or is the mesh bag and whatever is put in it, going to be the only means of filtration. If it is just a pre-filter requirement, then you don't really need anything inside the bag, as this is a mechanical filter. But you don't want the bag to collapse around the pump and possibly cause a plug up. Was this "bag" actually designed to be used as a pre-filter, or is it one of those laundry bags with the wire frame? If it is the only means of filtration, then filling the mesh bag with pot scrubbers, will do the job of providing surfaces for the bacteria to colonize. The "scrubbies" [nylon bun shaped type] will act as the bio-filter material,just pack them into the bag, as many as you can. Be sure you do not block the pump's intake with anything. A "scrubbie" placed in front of the intake, may plug up with gunk, but the "scrubbie" it's self, should not be sucked into the pump, unless it completely unravels, which is highly unlikely. All that a pre-filter is there for, is mechanical filtration, to stop hard objects, like pea gravel, bits of twigs, etc, from being sucked into the pump's impeller and doing damage. Hope this helps, "Horton"

I have a Labradoodle who turned out to be a shedder so we have quite a lot of pet hair to deal with, so I've gone with a prefilter which seems to work well, i do plan at some point to get the ducts cleaned but I really want to keep the big stuff and the dander out of the system so the prefilters seem to have worked well although I still see quite a lot of the fine grey dust that is characteristic of human/dog dander/dead skin cells on the furnace filter - I was finding a monthly change of filters rather financially challenging (I run the furnace fan 100% of the time, over the summer it with the humidifier proved a great benefit in our dry climate, no more static issues, and no mould issues (I can't see how you're going to get significant condensation etc with a system that is not cooled but just circulating air) so I went with the 'permanent' electrostatic filters, they say they don't require power. I bought two, so I put the clean one in, vacuum then hose the other one off - seems to work pretty well. I was kind of slack and went a few months using the same pre-filters, vacuumed the cold air return grille regularly. I did notice some leakage round the edges, so I am installing weatherstripping round them so they seal better. May be overkill but I think it'll keep the air in the house cleaner. I intend to put in a uv air steriliser too, at some point.