| Sansai
Join Date: Jul 2005 Location: Fremont, CA Posts: 235
| Hi Steve, My number is (510) 659-0267 You’re getting some good feedback from a couple of people here. I would like to see you aim for a one hour turnover. 1 ½ would be acceptable though. Long ago the folks who raised koi found out that the easiest and cheapest way to keep a pond clean is to remove the waste as fast and thoroughly as possible. They constructed large sumps that would move water slowly (without turbulance to keep fines afloat.) and hold that water long enough to allow the all but the smallest particles to settle. We’ve improved some, but settling is still the best particle removal for the price. They added brushes to a second, large chamber so a lot of the remaining fines would have a chance to settle there. And still a little got through. Along came bead filters and the hobby changed direction. Here was a single filter that caught all the waste and did the bio too. The most apparent problem that they created was a tendendancy to dump them every week or two. They were plugging up regularly. There were some serious additional problems, but the hobby hadn’t moved forward enough to see them yet. Now, the sump has returned. Its only purpose is to allow waste to settle out of the stream of the moving water as soon as material is developed. Its best if it’s designed as a circular clarifier (vortex sump.) but few of the sumps we call vortexes are benefiting from the mechanism that makes these sumps do the job they are capable of. Your sump will do its job if it’s followed up with the bead filter. The 2 together complement each other to provide an excellent mechanical separation. I can’t imagine anyone thinking matala or any mat should be in a settling chamber and not thinking at all using the concept of filtering material before moving the water through a bead filter. The bead filter is one of the most thorough filters available and will stop anything J-mat or matala will stop. Their main problem is that like, matala; they hold the waste in the stream until it’s dumped. And with either, you should be cleaning them much more than a couple of times a week. Even a poor settling tank will help remove most of the waste before it ends up trapped in the bead filter or mats. Following a settling chamber with a bead filter removes most of the waste before the beads and allows the beads to trap the fines that still get that far. (Beads will trap fines down to as small as 5 microns.) Next, comes the main advantage of bead filters. You can dump them easily. In a minute or two, while you’re feeding or just looking at them. It’s so easy you can do it as often as it’s needed. The bead filters or any other filter that isn’t auto cleaning 100% of the time should be dumped every day. Even twice a day. The waste trapped in the stream is making fish shit soup. The longer you leave it there the better the heterotrophic bacteria will appreciate you. A caution. Buy a filter rated at least 100% of the flow you plan to need if you are using it as a particle separator but cut it’s rating in ½ if you plan to use it for bio-conversion. A microscreen that removes the waste from the stream will be a little better than a sump, but that’s something you can retro in the future since your sump will be 36” wide. J-mat is just the right combo of surface area vs oxygen carrying water capacity. A matala mat the same density would be just as good. I believe the other densities are just manufacturer ‘stuff’ that can be sold to somebody. An advantage to either of them is its open construction that removes the need to space the mats or chop them up. Back when we were using dense mats like open cell foam, hobbyists resorted to spacing or even cutting the mats into small cubes to assure even contact and avoid channeling but that’s not necessary any more and allows a loose mat like J-mat to offer a much larger surface area. J-mat and the Matala equivalent are both excellent media, but there are many other medias available and you may find something another hobbyist is willing to share. You will see lots of set ups that run the skimmer to a 3-way valve. To add to the problem, they are using 2” skimmer lines. So they try to balance the pump suction between a 4” bottom drain line and a 2” line that’s often half again as long a run as the bottom drain line. Then they close the bottom drain off until the skimmer line has enough suction to draw. Now tell me why we install a 4” bottom drain so we can valve it off to operate along with a 2” line. Dealers for the most part don’t know a great deal about hydraulics so they couldn’t figure out how to make a skimmer run properly into a sump along with a 4” line so an easy fix was to run a separate circuit and the problem went away. The thinking that it provides for redundancy is true enough but it’s a very limited approach to pond design. A pool skimmer will give you the service you want. Get one that can be cut so it will accept a 4” connecting boot and run it to the sump using a 4” line. If the skimmer is line is a short run to the settlement, you can go smaller, but let me know before you do just to make certain it will work. Settling won’t be a great a problem as bottom drains because all the material they carry floats. I would prefer to see two pumps in parallel drawing through the sump into the bead filter. That will allow true redundancy so one pump taken out of service won’t kill off either of the circuits. More importantly, you will be able to shut one pump off for the winter and cut your power consumption in 1/2 without a need to purge a loop in the spring if you did it with separate circuits. Aqua-Flo is an excellent pump as are Performance Pro and the Sequence 1000 line of pumps. Hold off until you have determined your final layout and I will help you select the right pump for your system design. It’s a good idea to look at the pumps locally available first. If you run into trouble, parts and help is readily available. If you need a pump for waste, you might want to consider configuring your primary pumps so they can do that work when needed. That AquaFlo isn’t being used as a sump pump is it? Some sort of automatic pumping should be incorporated into the pit. I assume the twin feeds to the Bio-chamber will be similar in construction so they will share well. Lots of folks do the balance inside the chamber to eliminate another bulkhead and the distribution should be a little better distributed. If possible balance the slope so both sides benefit. Consider placing the air stones on top of the mat. Stones at the bottom of an up flow filter will cause the water to channel and bypass most of the filter. Jet streams are important to a small pond to give the koi the exercise they need. But they don’t need it 24/7. Jets use a lot of power and should be on for an hour 2 or three times daily and left off at other times. I actually think a pump should be installed just for that and placed on a timer. Two or three jets can be run off a single pump to provide strong cross currents that will give the type of exercise that is normally available at depth. At the same time, the jets can be oriented to aid in sweeping debris toward the drain. An air dome line to the bottom drain should be added. |
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