Ok, I am late to the game when it comes to this post but I will throw some thoughts out there. First of all, I believe the original question was why do clean outs in the spring? I believe this is due to two very different reasons. One is about marketing...because we can. People expect to clean things in spring, whether it is the house, the lake cottage, the garage or the pond. Even if a pond does not need cleaning, consumers are conditioned to expect or ask for spring maintenance. One of the posts on here spoke about making sure customers are given the knowledge they need to make good decisions about their pond. How many contractors out there would walk away from a spring clean up job when we know it is not necessary? I am treading as lightly as I can but this comes down to your "approach" and what your reasons are for being a pond installer in the first place. Is it purely about profit or about doing something you love and are passionate about? The advice and knowledge you give your customers will reflect this idea. I have alot of feelings on this issue but will keep them to myself and focus on the question at hand. A second and more regional reason for spring clean outs is simply due to the fact that they are necessary. I operate in northern Indiana and my installs experience a wide range of debris and litter, anywhere from virtually none to some that need almost daily maintenance, even in the winter. It really boils down to location, the surrounding conditions and the customer themselves. It is nice to think that all customers will act rationally and do what is necessary to properly maintain their pond, but that is a fantasy. I have customers who refuse to have leaf nets installed, want no fall maintenance, won't utilize deicers or aerators and a few who pull the plug in December and cross their fingers until March and hope for the best. No amount of education has changed their behavior and as long as they are able to get away with no (or minimal) negative consequences, they feel justified that they are correct and I am just trying to push my services or products on them. Yet they are the first to call in the spring wanting "spring maintenance" and year after year I explain to them that the job will cost more in the spring alone than if they hired me to do the work in the fall and spring. Again, some people just can't be convinced no matter how honest you are with them. So in some cases it has to be done in the spring "just because". Another reason spring maintenance makes sense in a northern climate is it causes the least disruption to the ecosystem at that time. Cleaning in June for instance would result in a much greater disruption to not only the bacteria colonies but also to the fish which are much more active, the plants that are actively growing and the other aquatic life forms present. So we try and do the work as early as safely possible and put the pond back together as quickly as possible to enable the system to get online and working toward full capacity. Again, this varies from region to region because my jobs experience a virtual complete beneficial bacteria shutdown throughout the winter months and any debris/litter that does make its way through nets, skimmers, ice, etc... basically sits unchanged until the spring. At that time it either needs to be removed or it will decompose at a faster rate than what the beneficial bacteria can process it because of the time lag in water temps matching air temps. Another corresponding issue here is the use of so called "cold water" bacteria and the types and strains of bacteria used in those formulations. I have seen conflicting reports (and nothing concrete in either the positive or negative proof) that indicate cold weather bacteria blends are more anaerobic than aerobic. This is a concern in my jobs since we have ice cover for a significant time period and the last thing I want to introduce into the pond is a bacteria that will break down debris but produce sulfur gas as a byproduct. I would rather leave the debris and get it out in the spring than risk a fish kill during the winter. Just my approach and opinion. Which leads me to the more contentious subject on this thread....how a pond is built as compared to how much maintenance it needs. I will make no broad statements or generalizations but the minute words like never, absolutely, always, in all cases, etc.... are used, then the argument begans. To say a pond will never need cleaned if it is constructed properly blurs the real issue at hand. First of all, who is the arbitrator of what constitutes a properly constructed pond? And what does the word pond even mean? Are we talking about a goldfish pond, a water garden or a koi pond? Each case is different and will result in a different construction technique. Secondly, how many of us have an ideal client base that write blank checks so that we can do installs exactly as we want to? Quite honestly, I have never done a single install to the level of quality I demand of myself quite simply because not one single customer is willing to pay for it. We each have different economical factors at work and in my area, the pick up truck landscapers and big box store DIY kits have driven the price down so low that it often leaves me wondering why I still try to compete. Add to that the pressure from the "build em in a day" companies that come and go each year and the damage they do to the marketplace from failed installs and the perception that all pond installers are questionable at best and I work in a market that requires me to scratch and claw just to convince people they need a skimmer and filter unit. And then I see and read information that claims the "correct" way to install is xx skimmers, xxx filter units, xxxx gph pump, etc, etc... and I just stop and shake my head. Maybe we all would like to build that way but my reality is I have a budget to work with and if I built in the ideal manner, my budget would be gone on just equipment and I would have to provide my labor for free. So I have to install in a manner that maximizes the capabilities of the equipment that I can squeeze into the budget and I have to educate the customer on the costs/long term effects of building in this way. If they clearly understand what I am telling them, I do the job. If not, I walk away because it will only lead to trouble down the road. What I have learned from my experiences has led me to develop my own installation method that addresses the challenges I face. As such it has also led to my own approach on cleaning and maintenance, including spring cleaning. I don't do "pump and dump" cleanings each spring in jobs I have built and instead have a straightforward cleaning, vacuuming, filter service that is less invasive and stressful on the system (at least I think so). Are my ponds built to the standards others may have set when it comes to "properly constructed"? No, but they are built to the standards the customer has set regarding budget, level of maintenance they are willing to do, proper function, health of the ecosystem and the level of expectations they bring regarding water clarity, debris, etc.... If they want crystal clear water and not a hint of debris, then they must be willing to pay for that type of install. When faced with an estimate for that type of install, the first response is that I must be crazy. If I manage to not get kicked out of the house, then we have a more realistic conversation about what they want. For those of you that are able to "sell" the perfect install, more power to you. I don't resent the fact you have such customers or that you are profiting from performing work to a high standard of quality. But not every customer wants a Mercedes and as an industry we need to address how we can sell Kias that still function and perform properly and meet the level of expectations the customer has for any given price point. A very big part of this is education and another huge dimension is contractors letting go of deciding what is right and wrong when it comes to installs and instead paying attention to what works and what doesn't, even if it goes against some set of rules that exist for what a "proper" install is. One comment heard in my circle of contractor friends is that a bad installer can make good components fail and that a good contractor can make bad components perform well. As we gain knowledge and experience, we find ways to make a less optimal install perform better than expected. We are no different than the mechanic that can make a car perform better than the next guy even though they have the same tools and parts to work with. As this discussion moves forward, we need to focus on how we each have found ways to optimize a less than perfect situation and how that can be applied across the board to all installs. That type of knowledge will determine what a "proper" install is and how well it should function and perform. But until we all have a way to talk, communicate and share our ideas, knowledge and experiences, we sit around and protect our own ideas and feelings on what is right and wrong instead of spreading that knowledge and experience industry wide so that everyone can benefit. As a final side note to this discussion, let me point out one last thought. The pictures posted show a "clean" pond. I am making no assumptions here in any way but when you talk about how clean a pond is, I would like to see the specific data from that pond...ph, ammonia, oxygen levels, etc... I have seen many "clean" ponds with dead fish present (not saying that is the situation in this case, just sharing my experiences). I would also be curious to see a picture of the same pond with the gravel scooped away down to the liner and the resulting pile of gravel put into a bucket and strained for debris/sludge/sediment. Not because I want to question the claims of how clean the pond is, but to have a baseline comparison of how a pond in my region would look given the same test (scooping out the gravel).