Good question Kong. When folks design for 'flow' they tend to put in very large drains-- which over time, act as settlement chambers. And the bacteria matrix has a cement like quality to it as it seals in slurry at the base of the pipe. Experiments and research by NI ( Nigel Caddock) showed that pipes can fill 1/2-3/4 of the diameter with this slurry over time- effectively closing off the flow from that once large piping.
Too small, on the other hand, will block from physical obstruction ( leafs, pine cone, acorns) and will also limit the overall turn over of the pond's water thru the filters. And these days we want at least 1/2 of the pond's volume traveling thru those lines to the filter each hour.
that is why my latest design abandons that thinking entirely and dimply dumps the content to waste after a low pressure drop to a specially designed sump, but 12 hours a day circulates water to the main sump in a traditional way-- in other words, it dumps its collected content every 12 hours.
Interesting comment: Today I did a major cleaning of a 120 gallon show marine tank. The design is a typical Oceanic design which means the water flows to overflow sumps located within the back of the tank itself. This system has an overflow gate design as well as 'silencer' pick up and return within the overflows. Well after two years plus, the tank was showing signs of excess organic build up based on tested water quality parameters and physical algal growth. The removal of the pipe work within the overflow towers showed that the space within the unit was collecting dead material and detritus and collecting it at the base, over time. A flush of the overflow chamber compartment produced that 'bad smell that you don't want to ever smell in a fish system'. Once flushed, the sump was instantly cloudy and nasty. The FFs starting working over time! The foam produced was equally nasty.
I could no help but think of this thread and the issues of what builds in drain lines. I am excited to share the new design of 12 hour interval flush of the drains of a koi pond. It requires one piece of electronic value. Thats all and the clean out is pump driven rather than gravity dependent ( which I think is the 'set up enabler' to settlement in traditional lines). JR
Recently, I have posted about my pond nitrate have been staying above 50 mg to 100mg even with daily flushing and once a week whole filter chamber cleaning.
Originally Posted by JasPR
A thought came to me, I should flush the bottom drain pipe 3 times a week and see whether I will solve the high nitrate problem. The 3 bottom drain pipes, longest is around 20ft to 10 ft to the settlement chamber.
Yes, indeed it immediately lower the nitrate to 25 mg. Therefore, JR, you are right that the drain pipe act as a settlement chambers.
I had the same problem.Although the pipe was not totally Blocked.I cleared mine following this method. With a long lenth of 1i/2" pipe flatened at one end so as to fit under the lid of the bottom drain.Whilst the main pump on the filters was running I poured a packet of pure sodium percarbonate into the other end of the pipe. I then monitored the inlet to vortex. Once you see anything going into the vortex. Stop the pump, shut the valves and wait a few miniutes. This will allow the time for the stuff to dislodge the debris. Then flush every thing through the vortex to drain. There is a small risk that some sodium percarbonate will get back to the system which will raise the p.H slightly. It may take a couple of goes to clear. I do it now every few years and always puts a few mv on an ORP meter afterwards. ! packet of sodium percarbonate is about £2 . Sodium percarbonate when mixed with water becomes sodium and hydrogen peroxide. Works a treat.
Biofouling is nothing new, Marcus Aureilius Antoninus understood this living force. Don't forget, 90% of the cells in our bodies are microbial in nature.
Originally Posted by cookcpu
yes, that's exactly right and logical if you think about it. When one sees nitrates settling in at higher levels that 50 then there are a few basic things you can investigate
1) your source water-- lots of tap water had a suprisingly high nitrAte level. If you see this, I'd also do a potable water test.
2) sumps- sumps are not being drained often enough. The bacteria that can breakdown protein reproduce every 20 minutes. that means that an entire population of say 10 million can become 20 million in 20 minutes! They are much faster than your nitrifying bacteria!
3) Drains-- depending on size of piping, turns in the line and LIFT into a sump ( just because water flows that doesn't mean slurry folows as well!) you can easily turn a drain into another sump! The most common version fo this has a drain pipe as a stright run but then a 45 degree turn up into the sumps floor or walls. This collects LOTS of detritus and starts the process of slurry production. once the biological ooze sets up, you have a bottleneck for additional biological residue to collect and form massive bacterial colonies. That is why I'm reintroducting the old Japanese method in a modern design. A open air flush ( or a pumps pull to waste) and clean out every 12 hours is ideal.
4) your test kit! Make sure it is fresh, stored properly and accurate. Having two kits is a good idea when in doubt.
5) Just too many fish being fed too often too much. This is a case of ambient ammonia just being impossible to maintain for any period of time below 50. The concept of an 'over active filter' comes in here. A concept that seems difficult to grasp for many people as the filter is universially viewed as 'all good, and only good'. But a big nitrifying reaction is also a source of pollution-- ambient nitrAte that is way too high.
If you are putting 70 gpm (1Hp pump) thru a 4 inch gravity feed pipe, I can't imagine any particle sediment accumulating unless you have a severe design flaw.
Originally Posted by kingkong
Not really the point Kong. It is the combination of resistance from the walls, the sticky material that bacteria cause and the slow accumulation over time ( not just the falling out of detritus and if I made that impression, my apologies). I'd defer to an engineer but the same boundary layer that builds along the sides of a vortex is INHO also present along the walls of the pipe. That 'slow' layer is where the bacteria builds. You, yourself straightened me out on the idea that bacteria grows all over your pond walls, pipes and drains. And even on a 'clean' wall, if you take a wall paper scraper, you will remove a significant layer of bacteria matrix and algal growth ( reds, greens, deep greens).
It was Nigel Caddock who created and designed the drain plumbing design ( along with Waddington) that worked its way over here in the 1990s that we are discussing. His students and collaborators in the UK and by colonization/instruction in the US in the midwest and south and south west that took up this design and spread it here in the USA. In that design that was omni- present in the 1990s websites, was this inherant weakness. Indeed most ponds of this design in the USA are 10- 20 years old. And it was Caddock that showed us pipes of 4- 6 inches that were caked even when using indiviudal motors for EACH drain line ( which was the recommendation of that era). Most of those as I recall were piping work in use for as little as five years.
This can be easily investigated thank goodness. A plumber's or a swimming pool installer's video camera and snake can be used to eye ball the pipes inside. Now THAT would be an interesting article, don't you agree? JR
P.S. force is something of an illusion in the water. Indeed there are entire marine companies that service ships and clean their propellors and hulls of 'biology'. Even propellors that spin at impressive RPMs. For what its worth.
I recall a pond installer of some renown who once redid an entire koi facility to modernize the filtration. He slopped the floor of the pond from left to right ( length wise). On one end he put the drains and on the other, he put in a large number of pipes ( only 2-3 inch diameter as I recall). The idea was that each of the pipes would be driven by powerful multiple motors and they would 'sweep' the floor towards the drains. The fish and their tails would keep the mulm in suspension ( I kid you not). Well the pipes were indeed impressive on paper and the 'jets' from the piping did exit the pipes- and moved water about three feet of the 18 foot length!!! The pump room was like the surface of the sun!! Hot hot hot. But the water movement was minimal. lesson learned.
I do want to be positive about bottom drains as a concept and feel I should make an additional post so as NOT to leave the wrong impression-- for the average ponder and casual koi keeper-- a drain design is FAR superior to sump only filters ( THOSE BLACK BOXES WITH A STRAINER) or inpond pick up motors. The reason for this is the drain is located in the ideal area to move 90% of the physical waste to the sump or prefilter to be removed! Kudos, excellent and thank you Japanese masters, Peter Waddington and Nigel Caddock!! Great great advancements for the day and into today!
But with every advancement comes new problems and a new reality. And rethinking the concept is NOT the same as throwing out the baby with the bathwater!! LOLS
Today we know a lot more about filtration. That is due to the fact that our advancements have taught us more about the nature of pollution in a closed system.
So if you are committed to a drain/piping system-- tweek it. Add that T assembly that Nigel came up with 15 years ago now. It is a natural adaptation to a growing/aging problem.
If you are pondering a new pond the way I am, think in terms of performance no longer as HOW to gather organics-- but rather how quickly you can REMOVE them from a system. So NO amount of straining can compete with the ability of protein skimming to remove dissolved material in your water. And no drain design is going to compete with a drain that removes the waste FROM your system ( rather than collecting it for dumping weekly) every 12 hours. Or its collected form from the system sumps every 6 hours-- THAT is a CLEAN system. And it requires less muscle, just more targeting of organic build up.
The point of this post is to say -- this is not about rejection of a particular design or piece of kit. But rather a shift in philosophy after seeing symptoms of less than ideal results in yesterday's advancements.
For what it is worth, JR
Originally Posted by JasPR
First we must define what exactly is accumulating and why.
1. Incrustation in nature
2. a biofilm biological community
3. an accumulation of fine particles due to snags or lack of movement
I am still not sure what is meant by adding a T like Nigel said.
Originally Posted by JasPR
Which way is the tee pointing? Up like a vent?