Sign in to follow this  
Followers 0
Randy

No hole Siphon primed by venturi

25 posts in this topic

Siphon requires no holes to be drilled.

Clear hose instead of pvc for the siphon would allow observation of operation.

An overflow pipe with venturi tube running into and up the siphon primes the

siphon removing air.

The venturi is inside the siphon to prime it.

Venturi could enter the siphon by way of output end

instead of as diagrammed by a hole or tee in the siphon.

Cheap, Easy and can be scaled up to large pipe? ..

Comments?

The actual picture is larger, but the forum is displaying it smaller,

almost too small to see the details.

Randy

Share this post


Link to post
Share on other sites

Hi Randy,

I'm not sure what the benefit of this syphon arrangement is. It looks more complicated than the autosyphons we currently used. Have I missed something?

Gary

Share this post


Link to post
Share on other sites
Hi Randy,

I'm not sure what the benefit of this syphon arrangement is. It looks more complicated than the autosyphons we currently used. Have I missed something?

Gary

Gray,

I am confused as you are about the complication you speak of.

It has 3 parts: siphon hose, overflow pipe/hose and a venturi.

The outlet of the siphon must be under water before the siphon can be primed.

A leak only drains a few inches of water at most, not the entire tank.

I might be missing something as well.

Could you list some links to some diagram/design/pictures or other information

that explain the less complex autosyphons of which you are referring to?

I know of the loop siphon, but I was concerned and unsure if that siphon

would function under all conditions and larger siphon sizes.

Are the A,B,Cs of these different siphons explained somewhere or

does one have to hunt down details about each one separately?

Thank you

Randy

Share this post


Link to post
Share on other sites

Randy,

Have a look at the siphon types I outlined in a PDF a while ago. It may help explain the operation of the Tantalus auto-siphons most of us use (those that use Flood and drain that is!)

Cheers IanK :D

Share this post


Link to post
Share on other sites

Hi Randy,

You can find an image of the auto-syphons many of us use......here.

There's another type and I'm still looking for a photo of it.

I'm aware of the loop syphon but I don't much care for them. The examples that I've seen are subject to blockage.

Gary

Share this post


Link to post
Share on other sites

Hi Ian,

Just had a quick look at your pdf. The system 3 is probably the configuration that comes closest to my three AP systems at present. I have bell siphons in all the growbeds and growbeds are all higher than the fishtanks.

You suggest that the flow in time can be adjusted by varying the pump flow rate but in practice I have found this to be problematic. In fact, I have progressively outlayed more and more money on bigger more powerful pumps to be able to achieve this goal.

The problem as I'm sure you have experienced is that you just won't have enough flow to the growbed to initiate the siphon and the water will just spill over the top of the standpipe. This defeats the purpose of the bell siphon as you just have a continuous flow unless you can get that water into your growbed in a hurry.

My solution to this problem was to pump the water into a 200 litre barrel that sits high above the growbed (I have to use a stepladder to look inside)

and dumps a very large ammount of water via 40mm pipe to the growbeds.

I have just today converted one barrel into a swirl filter/bio filter so it has the added advantage now of being a pre-filter for the growbeds.

You also haven't made any mention of solid waste, particularly in the CHOP system ..... how is solid waste removed from the tank as it would seem from your diagram that the water gravity feeds from the top of the tank to the growbeds and then is pumped from the sump to the fishtank. If there's no pump in the fishtank then there must be a lot of solid waste in the bottom of the tank.

Dave

Share this post


Link to post
Share on other sites

Hey Dave, how are they hangin' in Brunei?

With regards to the pump flow rate; my pump is 7000LPH (at zero head) but I only require about 1200LPH to the Grow Beds (at about 4m head), so I have a By-Pass valve on the supply line to the GBs which lets water back into the FT before it gets to the GBs.

This serves two purposes;

1: gives continuous aeration to the FT water by "spraying" on the surface of the FT water.

and 2: allows me to adjust the flow to the GBs above by opening or restricting this bypass valve without having to adjust the individual valves to the GBs once they have been balanced for Flood/Drain sequences between the 4 GBs. Then I can easily adjust the F&D times by just using the By Pass valve to alter the Pumped flow rate.

The pump was sized for this purpose and it works very well. It is always best to size your pump for the calculated required flow rate, taking into account friction losses from fitings and the required flow at the static head height, then double it! It might cost a couple of bucks more for a bigger pump, but it is definitely worth it in the long run.

As for the CHOP diagram, yes you are correct. I should amend it to show the drain leg of the TEE reaching to the bottom of the tank to try and draw water bourne solids from the bottom of the tank. I have used this on my fingerling tank over my fish tank and it works OK with a bit of a stir every now and then.

In my F&D system, I rely on the GB media to be the sole filter to extract the 25% of fish waste which is solid. Some practitioners advocate filtering out this solid matter before getting to the GBs (especially when using DWC tanks) and only utilise the 75% of disolved nutrients, but I let the solids enter the GB media, to be not only the bacteria host but, to filter out any solids. I have a slotted PVC half pipe at the base of my parabolic section GBs which allows any residual sediment to be removed at intervals, without disturbing the GB media.

IMHO, the introduction of a sump to a CHOP system presents both pluses and minuses, with effective solids removal from the FT one of the minuses. It seems to me that it is far more beneficial to have a pump in the FT to deal with moving solids than have the pump in a sump doing nothing for aeration or solids removal.

Perhaps I am a purist, who likes to stick to the simplest ideals of AP, thus using GB media as both Bio-filter and solids filter, no sumps and no extra equipment to go wrong or break down.

Good to see your system working well and we can all learn from our own experiences and those of others willing to share.

Cheers IanK :D

Share this post


Link to post
Share on other sites

Hi Ian,

Perhaps I am a purist, who likes to stick to the simplest ideals of AP, thus using GB media as both Bio-filter and solids filter.......

So long as you recognise that the two functions are at odds with each other.

Gary

Share this post


Link to post
Share on other sites

Hello Gary, how's life on the farm? Looks a bit bare now you have removed all the GBs and FTs.

Yes, I am aware that serving both purposes in the GB media is creating both aerobic and anaerobic processes, but I would like to try and keep the system in a simple loop without any extra piping, plumbing and fittings.

I feel confident that the fish solid waste can be handled by the media and will promote the growth of appropriate bacteria to break it down. I know that this is at odds with the aerobic function of the Nitrosomas and the Nitrifying bacteria, but with a bit of help from the worms, I feel sure that it can be handled without promoting anaerobic "hot spots". Also remember that I have a sheilded bottom scavenge area at the base of each grow bed that I can remove any solids that work their way down through the media with a siphon hose. This can be done without disturbing the media in any way and the "sludge" gathered can, and will, be used on the soil garden. We will see how it goes. The pic is of the slotted PVC half pipe I fabricated for the bottom of the GBs.

Keep up the good work and I am looking forward to the installation of your new system. Pass on my regards to Jan and how are the yabbies doing?

Cheers IanK :D

Share this post


Link to post
Share on other sites

Hi Ian,

Hello Gary, how's life on the farm? Looks a bit bare now you have removed all the GBs and FTs.

We're currently experiencing the joys of daily testing and water replacements as we struggle to keep our fish alive in the absence of cycled systems.

Also remember that I have a sheilded bottom scavenge area at the base of each grow bed that I can remove any solids that work their way down through the media with a siphon hose. This can be done without disturbing the media in any way and the "sludge" gathered can, and will, be used on the soil garden. We will see how it goes. The pic is of the slotted PVC half pipe I fabricated for the bottom of the GBs.

I like the slotted pipe idea and I'm looking forward to seeing how it works in practice.

I'm coming to accept that, if growing plants is the priority (and you can grow enough to provide a reasonable return on the investment in a system, then a system can be run with relatively few fish......

Keep up the good work and I am looking forward to the installation of your new system. Pass on my regards to Jan and how are the yabbies doing?

Will do.........and the yabbies all expired due (we think) to overfeeding and temperature issues.

Gary

Share this post


Link to post
Share on other sites
Hi Ian,

So long as you recognise that the two functions are at odds with each other.

Gary

Hi Gary

Can you elaborate on this a little more? In the last couple of days I have just made a Swirl Filter from a 200 litre drum that is both a mechanical filter (at the bottom) and a bio filter (at the top) I arrived at the design after a lot of internet research and found diagrams and info. by hobbyists (Koi pond keepers) and commercial filters. In many of the filter designs I found, the mechanical and bio filter were housed in the same unit.

In the growbed I would think that the same situation exists. That is at the bottom of the growbed, mechanical filtration takes place and solid wastes are deposited, while in the rest of the growbed, media and surfaces act as a bio filter.

Why then are the two processes at odds with each other?

While I agree that you can never have too much filtration, adding more filters costs time and money. like Ian, I would prefer to keep the system as simple as possible. As I now have 3 systems, it takes a lot of time to clean the FT and refill. I am also investing in Barramundi now rather than the hardy (but free) Tilapia. Hence my motivation to add more filters.

Dave

Dave

Share this post


Link to post
Share on other sites

Ok, after trying out some experiments, I am unsure that

enough venturi suction can be created to prime a siphon.

That idea must be put on the back burner.

Please provide your feed back about the below thoughts about

simplifying, reducing expense, skill requirements.

I don't see why more fish tanks are not lower than ground level other

than the extra work it takes.

Placement of the fish tank so only 6" is above ground level makes external

environmental temperature changes effect the fish tank temperature less.

A in ground fish tank allows for a lowering of the grow beds

which reduces bed framing costs.

The lowering of grow beds would require sitting down to do your

gardening .. which would be no different than raised bed gardening.

Grow beds could rest upon cinder blocks instead of custom

made wooden frames, requiring skills one might not have,

saving time and money.

Trade labor to dig the fish tank hole for expense of framing the grow beds.

If a hole is to cut into the bottom of a grow bed, why is it a toilet flush

valve not work instead of using some kind of siphon?

A float, like a soda bottle is attached to the chain.

The float and valve are contained in a 4"x4"x1' access box for cleaning.

As long as floating "stuff" can be keep away from

flapper when it closes, I see no other reason it would not work.

31AQ6A1TBCL._SS500_.jpg

Making some kind of a reducer to from the valve to pvc piping is the

only thing to work out.

No building a siphon, adjusting it or fiddling around to get it to work.

Thanks for your input.

Randy

Share this post


Link to post
Share on other sites

Randy, with the type of flush valve pictured, after the float has risen with the flood and pulled the flapper open, wont it sink with the draining water and allow the flapper to close before the grow-bed is fully drained? (I've not seen a valve of the type shown so I'm not sure how it operates.)

Share this post


Link to post
Share on other sites

Hey Randy,

Some good thoughts and some not so good thoughts, IMHO.

Sinking FT into ground = good thought, but . . . must be covered with a lid for safety of little kids. We have more drownings in backyard pools in Queensland than the rest of the Country put together! I don't know what your regulations are regarding Pool fencing, but ours are going to get much stricter in the short term. i.e. any pool of over 200 litres and 150mm deep must be permanently fenced, 1200mm high minimum, and child proof gates etc. This is required even for a back yard, external, portable spa bath with a lockable lid!!

Lowering GBs= bad thought. The ability to stand without bending is a great benefit. No framing needed, just stick your GBs on top of 4 masonry (or cinder) blocks as you call them, dry laid (no mortar) and stacked. Cheap as chips! and no special skills required.

Toilet flush valve = bad thought. Too many mechanical parts to go wrong and what ends the flush cycle? There should be no problems at all with auto-siphons, no moving parts, no special skills required to make one. People have proven with HSM and disasters that Float valves, flushing valves, mechanical timers etc etc have no longer a place in a functioning AP system. My Bell siphons have worked perfectly from day 1, no fiddling, no adjusting and no worries. I can't see why some people have trouble with them if they are correctly sized from the outset, are properly built with air tight joints, have an air break tube and with a short run to atmosphere. Even an induct vent to help them along if required.

Cheers IanK :D

Share this post


Link to post
Share on other sites

Randy, with the type of flush valve pictured, after the float has risen with the flood and pulled the flapper open, wont it sink with the draining water and allow the flapper to close before the grow-bed is fully drained? (I've not seen a valve of the type shown so I'm not sure how it operates.)

BTW, I think your original design reflected some original thinking. Should be good for small systems, but I don't think that you'd get sufficient venturi effect to pull enough air out of a large syphon to get it flowing.

Share this post


Link to post
Share on other sites

Hi Dave,

That is at the bottom of the growbed, mechanical filtration takes place and solid wastes are deposited, while in the rest of the growbed, media and surfaces act as a bio filter.

Using the grow bed (which is a biological filter by another name) to capture solids ignores the fact that bio-filters work best if sedimentary solids are minimised.

Contrary to popular belief, the beneficial bacteria do not oxidise solids but rather feed the ammonia and nitrite contained in those solids. The highest proportion of the ammonia and nitrite that is to be found in an aquaponics system is in solution (as it should be).

Capturing solids in a bio-filter simply clogs it up and creates anaerobic areas which, once they assume a certain mass, set up conditions which are exactly opposite to those we seek to create in a healthy bio-filter.

Your swirl filter is a good thing to add to your aquaponics system.....because it will hopefully capture the solids before they get into the grow bed.

Gary

Share this post


Link to post
Share on other sites

Thanks Gary. I see your point now and it is starting to show in my tank after only a few days of the 200 litre swirl filter and bio filter in operation.

Here is the really interesting thing... the water was so clear tonight when I fed the fish that I called my wife to come and watch them feeding. The barra put on a real show like performing dolphins, splashing around and showing off, almost eating the pellets out of my fingers.

Then a weird thing happened. I dumped some of the water from the bottom of the drum (filter) and then because no water was going in to the GB, the last of the water emptied out of one of the GB's and dumped some brown water. Not a lot, but just enough to muddy the water so I couldn't see the fish.

My conclusion after re-filling the 1000 litre tank and watching a few more flood and drain cycles is that I am now witnessing the cleaning and flushing out of the growbeds. Over the past few days the water in the FT has becoming progressively cleaner. there is a also a noticeable difference in plant growth.

So I am becoming a big fan of filtration and now building a second 200 litre filter. I've had to shop around a bit for bits and pieces but this one should enable me to have crystal clear water in both 100 litre systems.

Dave

Share this post


Link to post
Share on other sites

So I am becoming a big fan of filtration and now building a second 200 litre filter. I've had to shop around a bit for bits and pieces but this one should enable me to have crystal clear water in both 100 litre systems.

Good boy Dave. It's taken me a long time but I'm finally starting to get traction on the water quality issue. With each successive fish kill, the bleating of the purists is becoming less.

Interestingly, most of the loudest support for using grow beds to capture and treat solids is coming from those who have killed the most fish and/or those who have never actually grown many of them.

My next systems will feature a range of solids removal and treatment processes which will, once and for all, demonstrate that providing clean water for fish is not only commonsense but also cost-effective (particularly when compared to the cost of a fish kill).

Gary

Share this post


Link to post
Share on other sites

The second filter up and running. Managed to find a plastic laundry basket exactly 55 cm diameter that fits perfectly inside the top of the 200 litre barrel.

Covered this with fly screen and inside the basket aquarium foam and a bag of coral. This seems to be picking up the fine particles out of the water that rises from the bottom of the barrel where the swirl inlet pipes are located (25mm) A 40mm outlet at the bottom of the tank to flush out most of the solid waste.

Both of my 1000 litre tanks are staying clearer than they have ever been thanks to these filters. I am also being careful with the feeder pellets as they are the type that muddy the water if the fish don't eat them.

Plants in the growbed are looking better too day by day.

Will post a few photos as soon as I have a chance.

Share this post


Link to post
Share on other sites

Thanks Dave,

Some photo's would be great.

Bid... (... dashing out to check if one of wife's laundry baskets will fit into one of his 200 litre barrels.) :D

Share this post


Link to post
Share on other sites

Here's a few photos of the new filter. It's simple to make and works well to keep the tank clean. Very easy to clean, just remove the laundry basket and hose inside the drum and hose the muck off the basket. Open the 40mm ball valve every day or two to let some muck out.

Share this post


Link to post
Share on other sites

The last two pics show the inlet pipe, meant to create a swirl and dump the solid waste (poop) on the bottom of the drum. The dirty one is a week's muck. The clean one is after a squirt with the garden hose. So far so good, water clear. Easy to clean.

Share this post


Link to post
Share on other sites

Excellent Dave. If you multiply that quantity of muck by 50 you get a sense of the amount that goes into a system in a year. Even allowing for a reduction in the volume of solids due to worms breaking down, that's still a lot of material left in the beds to create anaerobic zones.

If you want to separate out the nutrients in those solids you can do so by putting them in a drum with an airstone. After a few days of brisk aeration, remove the airstone and let the muck settle out. You can then decant the water (complete with all of the nutrients) and put it back into your system. The remaining sludge can be given to the worms or put on the compost heap.

Gary

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0