The muck is all the algae that was making the water green. Single algae cells clump together, called colonies, to try and protect themselves from UV, normally UV from the sun. That makes them heavier and they sink. This all works very much like dust in the house. A lot settles, some is always suspended. There's no requirement to remove this stuff, but there's no benefit either. In high fish load ponds people don't want it because it consumes O2 as it decays and produces stuff that degrade water quality. A normal Water Garden fish load can handle that no problem and you have a lot of moving water so even less of a problem. People who have a Wildlife Pond like the stuff because insects live in it creating a food chain. That's good for dragonfly and damselfly larvae. The downside is how it looks. Longer term, as it decays it becomes smaller and smaller bits and at a certain size it's called DOC (dissolved organic carbon/compounds). The reason a name is given to that size is because it acts differently, acts like soap, can create foam on the water surface. As it continues to decay it gets even smaller (we're talking the size of bacteria) and it stops being a DOC. Another issue is as it decays it becomes lighter and over time (like a year or two) it starts to not settle back down and becomes suspended. Looks like pale ground pepper suspended in the water. That makes the water less clear, and just generally dirty. There are filters that can deal with that but it a bit tricky. There was a time when I just let it be. But I changed to removing it and keeping the pond clean. Just made keeping the pond easier, water clearer. It can be removed with a fine net, like those green minnow nets from the pet store. You have to scoop very slow. I use a vacuum I make that I call a Silt Vac In a small pond the net works very good. Your size pond is kind of in the middle, kind of too big for a net, kind of small for a vacuum. But the Silt Vac can certainly be scaled down and a smaller pump used. I also have a web page that compares the different kinds of vacuums. Really important to pick the right vac for the pond size and also what you're removing. For this fine stuff you need a vac that removes water. Trying to filter the water to return it is a real waste of time...tried many ways. Loose gravel makes vacuuming difficult. You can put a valve on the pump to reduce power and try to get the sweet spot where there's not enough power to lift gravel, but that slows you down too. I like rocks on the bottom but I like them mortared. That makes vacuuming really easy, even better than bare liner because no wrinkles and the rocks look nice when clean so it's a reward where seeing bare liner isn't so nice imo. If you do decide to vacuum it's nice to have a place to hook the hose to so you don't have to have a separate pump. This is how swimming pools are built, the skimmer has an intake that is sized for the hoses and the pump just sucks the hose into place. Very easy. Unlike a swimming pool though you need valve(s) so the pump exit goes into the yard. I used a separate pump because I cleaned other peoples ponds. This settling stuff will normally be on on going thing, just like dust in the house. There are ways to direct pump output to the bottom to keep the stuff from settling so filters can remove it. But that is more complex than it sounds. Your filter for example will remove some of this stuff but probably only maybe 10-20%. There are other filters that remove more. It's a whole deal.

Hi everyone, I'm a new member to the forum but have been reading posts on here since last summer when I entered the exciting world of pond keeping! Tons of useful info so I'm hoping some of you much more experienced people can help me out. We recently had a Koi death which was pretty sad. Actually we also lost five fish over winter (two goldies, two sarasa comets and a shubunkin). I was away for the entire period (it's at my parents house so they were in charge!) but apparently there was only one body found. We had a net over the pond so I'm not sure how the others could have vanished. Any ideas? I recently read that most people turn off their filters over winter as otherwise the water temp drops too far. We left it running full time (it's an Oase Filtoclear 15000 and Aquamax Eco 12000 so the economy function slows it down in cold weather). Should we have stopped it? If so, do you need to clean it out/restart the bacteria when you turn it back on? Other than that I don't think we did anything wrong. We slowed feeding (using wheatgerm) during September/October when it started to get colder then stopped altogether around November time. The running water would have kept a break in the ice. When I got back home and we uncovered the pond (April) there was a ton of blanketweed but the remaining fish seemed happy enough. We started feeding again about a month ago. There was no easy way to get the blanketweed out so I did a full water change yesterday and took everything out (why did I put so much gravel in the bottom!). At the time one of my Koi (Goldilocks for obvious reasons) seemed very docile and was hanging around just under the surface. He almost let me stroke him which was uncharacteristic and we noticed his tail looked damaged. I had to move all the fish (and four newts!) into temporary accommodation (using water from the pond) while I emptied the pond and cleaned it. When I was refilling the pond I checked on the fish and saw Goldilocks was lying on his side at the top. I thought he was probably on his way out so the stress of moving and different water temps could have finished him off. He was still breathing though so I quickly put him back in the pond. I know this probably wouldnt have helped but I couldnÂt think of anything else to do. I de-chlorinated the pond and added some biostart but didnÂt want to keep the rest of the fish in the "holding area" for any longer so dropped them all back in. Goldilocks never perked up and I took him out this morning, definitely not breathing anymore. I could see any other external damage apart from the tail but have taken some photos for your opinions. Is it fin rot and if so, how should I avoid it reoccurring? I dosed the new water with "Tetra Pond MediFin" and also "Bacterad Anti-Ulcer, Finrot & Flukes" treatment. Overkill perhaps but is that a bad thing? Anything else I should have used instead? Our pond is about 3000 litres (650 gallons) and has had the return pipe from the filter acting as a temporary waterfall/aerator until last week when I built a small waterfall. IÂm afraid I didnÂt test the levels before the water change. None of the fish we over 5", most were smaller. The remaining three are a little fantail nymph, a ghost koi, and a small shubunkin. I went to the trouble of re-potting all of the plants with hessian and gravel to stop them losing their soil. There was also a ton of sludge in the bottom of the pond, as well as the blanketweed. Is there a chemical/natural treatment to both problems that I can employ to save me the monumental task in future? It looks much better now but I donÂt want it to get so bad again. IÂve been thinking about a pond vacuum as well as multiple sludge buster & blanketweed treatments perhaps. At the moment weÂve only got a couple of barley straw bundles. IÂm not sure I should add all the gravel back in as it will make any cleaning harder in the future, although it looks nice and breaks up the liner. Sorry about the ridiculously long post and also for asking so many questions at once but I would be extremely grateful if you guys could help me out and try to make me a better pond keeper!

Short of breaking up your garage floor and excavating the edge along the basement, you're stuck. Doing the three accessible sides might be enough. (Or not.) From the Tuff-n-Dri website: "TUFF-N-DRI Basement Waterproofing System is installed only by Barrier Solutions Contractors. These contractors undergo training to ensure the highest quality application." This post was edited by worthy on Fri, Mar 21, 14 at 1:03

First of all the only reason to choose VAH is their magic lung blowers; if you are going to leave them out, there is nothing special about their liner-their claim to fame is strictly in the blowers. And as you point out, you don't get any baffles or filters if you go VAH without the blower. Other vendors will give you those with or without the fan. There is nothing special about the fans that come with a particular hood or liner if you are going with an external fan. 900 cfm is pretty much 900 cfm. (Except for mounting brackets and wiring, could mix and match internal blowers in many cases for that matter.) However, most in-line blowers are meant to go in an attic where they can be serviced. Somehow I got from your description you duct run may not be in an attic since you will exit through a wall rather than the roof. Don't seal up the fan where you can't get at it if it breaks. I'm not too sure how important the heat sensor really is-I'd take advice from someone who knows what they are talking about on this one. VAH only offers it on certain models/combinations so can't be a do or die deal. It came standard with my hood.