Indexing valves

[TCLynx]

I'm moving over some comments from the group wall to a Discussion to organize it all a little better.

Lets see how I do at this.  Making this change over about 8:45 eastern time on 9/25/2010

Well I was trying to embed the Shockwave animation of the indexing valve but couldn't quite figure it out.
If you click on the attached file below, it will play big in the browser window if you have shockwave on your computer.

[TCLynx]

Comment by George J. Thurmon 14 hours ago
Please explain indexing valves and how you use them without siphons. Does it take power to run one or does it work with water pressure alone?
If powered, how many watts does it draw? Thanks.

Comment by Daniel E Murphy 12 hours ago
@George, they are fully mechanical. No power needed. They rotate mechanically with water pressure.

Comment by Daniel E Murphy 12 hours ago
http://www.fimcomfg.com/

Comment by Rob Torcellini 12 hours ago
These workwell, but you have to make sure your pump is designed for a lot of on/off cycles. Also if one of the outputs is clogged, the entire
thing will fail. RubertOfOz from the BYAP forum sellsa modified one that
works well for AP. I believe he had the springs adjusted so it can work
under less pressure.

You can also make a sequencing valve that uses flappers...I think TCLynx made one?

I designed my own using a different technology....it's been running for the last 1.5 years with no maintenance! ;-) http://www.youtube.com/watch?v=u7XGME4kdJc

[TCLynx]

Comment by TCLynx 10 hours ago

Yes they are mechanical.

Here in the USA I'm one of the distributors of the same kind of Indexing valves that Rupert sells (He takes care of the rest of the world other than the Americas.)

Yes the Aquaponics Indexing valves are modified for use with Aquaponics and there is even a further modification I've been working with the company on for even lower pressure operation. I've been using one of these "gravity" modified valves on my big system for over a year.

The valves are made right here in Florida at Fimco mfg.

Yes the drawbacks of the indexing valves is they do require a certain amount of pressure/flow in order to operate properly and they require some means to stop and start the flow to the valve in order for them to index forward to the next zone.

It isn't the outlets clogging that cause a problem but actually debris getting caught inside the workings of the valve that can mess things up so I advise keeping sticks, leaves, large seeds and fish from flowing into your valve. I had a pump feeding one of these valve in a tank below shedding crepe myrtle trees and the valve was pretty darn full of debris before I realized it wasn't working properly. I have since covered the tank to keep the debris from being sucked into the pump.

Here is an image from when I opened the valve to see what had happened.

Now I think most of you might agree that this debris problem would have been a problem for other situations, and not just simply the indexing valve. Say if there were distrobution grids on the beds, those would be clogging up too.

Situation has been just fine since I covered the pump pit with some filter material (shade cloth would also have worked.)

I have never had a problem with fish poo, soft uneated fish feed or bio-slime clogging the valves. Actually, I think a coating of bio-slime actually improves the functioning of the valves.

The easiest way to install and effect the indexing of the valves is to have the pump feed the indexing valve directly and run the pump on a timer.

For my Big system I am running one Gravity Modified valve direct from my fish tank. There is only about 18" of water column above the valve and my pump runs constantly so I had to develop my own Automated low pressure valve to start and stop the flow to the indexing valve. (ya see, most large/cheap solenoid valves require a differential pressure of 5-15 lb to operate properly and with only 18" of water column, that wasn't available.) I needed something at least 1 1/2" and all the ready made automated valves that would work under my conditions ran between $400 and $1500 in price.

I've heard of one instillation where they used a solenoid valve before the indexing valve to control it. A set up like this would require a pump that produces enough pressure at the solenoid for it to operate and still push enough flow/pressure through the solenoid valve to provide the flow/pressure to operate the indexing valve. There is a bypass of flow so that when the solenoid is closed, the excess water is going back to the fish tank for aeration. I don't know the details of how well this system is working or not but I expect such a pump uses a huge amount of electricity for the actual amount of water it moves.

There is an animation you can see running on this page
TCLynx

[TCLynx]

Comment by ericjf7 4 hours ago
'Lo TCLynx - I suppose you're looking to field some of these questions, although it may be answered elsewhere - Is there a way to run multiple grow beds with a CHOPS system, with the only the overflow from the fish tank (850 gal.) operating either a distribution box, or the indexing valves, with minimum fall between the tank outlet overflow and the grow beds? I realize you mention an 18" head, but get the impression that a second pump (pressure) is involved, apart from the 'one pump in sump'. I am hoping to set up a larger system once the bugs are out of this one. Would leading one grow bed into the next with bell syphons result in greatly depleted nutrients in successive levels, or could that be dealt with by using decreasing plant volumes? I imagine the idea of 'float' (toilet tank type) shutoffs or switching has been tried and found wanting?

[TCLynx]

Is there a way to run multiple grow beds with a CHOPS system, with the only the overflow from the fish tank (850 gal.) operating either a distribution box, or the indexing valves,
Yes, this is possible. It does require some special designing to make it work but it is possible.

with minimum fall between the tank outlet overflow and the grow beds?
My set up using a specially gravity modified indexing valve and my special automated valve I am managing this with about 18" of fall and a huge amount of flow. (The Automated valve is a 3" valve and there is plenty more flow beyond that which goes to an overflow bed before flowing back to the sump tank)

I realize you mention an 18" head, but get the impression that a second pump (pressure) is involved, apart from the 'one pump in sump'.
This could really be done for a One pump in sump system where the pump runs constantly. Some time here I'll see if I can work up a sketch and description of how I might recommend doing it.

Would leading one grow bed into the next with bell syphons result in greatly depleted nutrients in successive levels, or could that be dealt with by using decreasing plant volumes?
This type of method "cascading beds" has been discussed elsewhere and there is one system that uses a method like this over on the BYAP forum. However I don't think cascading is the best solution unless you happen to be building on the side of a hill. The nutrients for the lower beds are not as big a problem as the solids tending to build up in the top bed and probably cause clogging in that bed, especially if the pumps flow constantly. I've found constant flow into beds experience far more slime and fish poo pavement buildup at the inlet sites than the beds that get intermittent flow. One thing that needs to be taken into account for cascading beds is each lower bed needs to be smaller than the one before to make sure that enough water goes through to make sure the lower siphons kick in and drain the beds, otherwise all might wind up flooded and the sump empty and pump running dry.

You can probably tell I'm not that big a fan of the cascade design even though I sort of do it a little. What I mean is I do have a situation where a gravel bed gets water direct from a fish tank and then the pump in that low gravel bed then feeds an indexing valve which feeds a line of grow beds. The line of grow beds being fed from the pump in the gravel bed are getting second hand water so to speak and very little solids make it to them but the plants are doing fine. (This would be a pump in sump bed sort of design.) but to get back on topic...

I imagine the idea of 'float' (toilet tank type) shutoffs or switching has been tried and found wanting?
Flush tanks work and I have even tested a flush tank with a gravity modified indexing valve but this requires more height and the toilet flush valve is going to be the most failure prone part of the system. I ran a barrel poincs system for about two years. This method is appropriate for situations where a really small pump is all that can be run and still allows for flood and drain of some grow beds and if some one wanted to raise a flush tank up about 18" above the height that a normal barrel ponics system would put it and run an indexing valve to feed more barrels, it could be done with a gravity modified 1 1/4" indexing valve but there are probably simpler ways to do it.

I'll see if I can now go and do some more clear explanations of indexing valves in some subsequent posts.

[ericjf7]

Thanks for the great info on your indexing valves - here's another question - Would these valves work with a low flow, 7900 gal/ hr pump with a 4" discharge - this is a recent purchase for use in the 5000 gal tank I'm hoping to set up shortly, likely with 3 or 4 large in ground grow beds returning to the sump housing the (submersible) pump - CHOPS system. We could incorporate an 18" drop in this quite easily, as we are starting from scratch.

[TCLynx]

Eric,
I'm sure something could be figured out for that set up. Doing a CHOPS system though generally means the pump is feeding the fish tank which then overflows to the grow beds. To do an indexing valve in that situation (and it can be done as I have been doing it for my large system for well over a year now) you will need to an a low pressure automated valve to quickly start and stop flow between the fish tank and the indexing valve or some other means of doing that. I don't know that starting and stopping the pump flow to the fish tank would provide the flow and pressure needed quickly enough at the valve to provide smooth operation.

Most definitely an indexing valve can be used for a CHOPS system so long as you have ample flow and some height between the water level in the fish tank and the surface of the grow beds, plus an alternate path for overflow water to be filtered as well.

You ask if the valve would work with a 7900 gal/hr pump with a 4" discharge? I don't know that I would call that a low flow pump since that is providing a huge amount of water each minute. You might operate several indexing valves with such a pump, keep in mind the large indexing valves are only 1 1/2" fittings. You would definitely need an additional path for water to overflow from the fish tank since the water going through an indexing valve is not going to keep up with such an inflow to your fish tank.

[ericjf7]

Sorry about that, my poor editing again, yes it is a high flow/ low pressure pump, max 15' lift, and I'm definitely looking to use the CHOPS system as well, with about a 3' lift from the sump if possible, although the 18" drop for the valves may make that a tough one. One answer may be to split the flow, as you say, and have a continuous flow to a larger media bed in which the bell siphon would also help maintain a more constant water level in the sump. This is already making sense as there are various levels (elevations) to work with, which would leave 3 or 4 media beds at a lower level supplied by the indexing valve. The pump is rated at 100 watts on the packaging, and 250 watts in the instruction enclosure, so fits in with our questionable power supply, although I did also purchase a small solar panel c/w a charger/inverter for battery backup. For this reason it would be best not to use power other than for the pump. Later we are looking to incorporate a small homemade windmill for power or pumping, as there is a fairly reliable daily supply of wind.



TCLynx said:

Eric,
I'm sure something could be figured out for that set up. Doing a CHOPS system though generally means the pump is feeding the fish tank which then overflows to the grow beds. To do an indexing valve in that situation (and it can be done as I have been doing it for my large system for well over a year now) you will need to an a low pressure automated valve to quickly start and stop flow between the fish tank and the indexing valve or some other means of doing that. I don't know that starting and stopping the pump flow to the fish tank would provide the flow and pressure needed quickly enough at the valve to provide smooth operation.

Most definitely an indexing valve can be used for a CHOPS system so long as you have ample flow and some height between the water level in the fish tank and the surface of the grow beds, plus an alternate path for overflow water to be filtered as well.

You ask if the valve would work with a 7900 gal/hr pump with a 4" discharge? I don't know that I would call that a low flow pump since that is providing a huge amount of water each minute. You might operate several indexing valves with such a pump, keep in mind the large indexing valves are only 1 1/2" fittings. You would definitely need an additional path for water to overflow from the fish tank since the water going through an indexing valve is not going to keep up with such an inflow to your fish tank.

[TCLynx]

Of course remember that if you have a system that is going to have a sump anyway, if it is reasonable to have a sump big enough to flood all grow beds plus some extra for pump operation and a top up valve, you don't need an indexing valve at all. The indexing valve only gives you real benefit if you can only fit a smaller sump or if you are running a system with lots of grow beds and no sump at all.

[Greener]

I'm interested in the CHOP+indexing valve discussion as this is the setup I'm planning on.  I was planning on using a pump in the sump on a timer that would pump to DWC tanks which would then all flow into the fish tank, which would then overflow into the indexing valve before being fed to the GBs and then the sump.  The timer would provide the on/off required by the indexing valve, but now I'm not sure if the overflow from the fish tank (especially after already being split across multiple DWC tanks and then rejoined) will be strong and abrupt enough to trigger the valve.  Do you think?  I also want to have the GBs after the indexing valve at close to the same height as the water in the FT, just a little lower.  It almost seems like I need to get a pressure valve or some automated valve before the indexing valve to deal with the slower initial trickle of the water in, but then why use the timer?

 

So I'm now thinking of going a slightly different route, instead I will let my pump run continuously (I'm planning on using the Laguna Max-Flo 1500; I called Laguna and the didn't recommend using on/off with a timer, they said if any debris gets into the well while it's off it won't start up again; so running this continuously is better anyway), so no timer on the pump, but instead of an indexing valve + automated valve I'm thinking of using a multiple-zone irrigation timer with electronic valves on a manifold, something like this (scroll down to see the package components):  http://www.mrdrip.com/sprinklervalves.htm , using a timer like this (still need to look around more): http://www.teakwickerandmore.com/asp/show_detail.asp?sku=BHX1043 .  What do you think of this?  Are these the solenoid valves you mentioned would require your tank on the roof to work?  I wonder if they can handle solids-filled water coming straight from the FT.. and I wonder about any exposed metals.  I will have to call them for more info if you think this is something worth considering.

 

Thanks for any advice!

[TCLynx]

To operate the indexing valves, even the gravity modified ones, require a certain amount of flow and some pressure to function.  The more tanks/beds you put between the inflow and the indexing valve, the more you slow down the action.

 

I do have an indexing valve running on my big system that is CHIFT PIST.  The water level in the fish tank is about 18 inches above the surface of the grow beds.  My pump runs constantly.  To make this work I had to design a valve that I could automate that wouldn't require a differential pressure but would allow a huge flow through when opened so that I could get that good gush to engage the indexing valve properly.  Here let me see if I can find my blog posts about it.

http://www.aquaponiclynx.com/low-pressure-automated-valve

 

As to the sprinkler type solenoids.  The inexpensive ones like you linked to, they generally do require quite a bit of pressure to operate and they don't have big openings so you don't get much flow through unless it is under quite a bit of pressure.  They will not work for gravity flow from a CHIFT situation.  If you find some that do with an opening of more than 1" for less than $400, I'm interested.

[Greener]

Thanks TC, your advice is really appreciated.  I had seen your automated valve before (impressive!), I guess I wasn't putting it all together though.  Anyway thanks for the reality check.

 

I'm now thinking a better setup for me might be to adjust the flows so that I can connect the pump (on a timer again) directly to the indexing valve.  On every flood cycle most of the water would go through the indexing valve, and then to a GB and back to the sump, but the other bit of water would go directly to the DWC tanks, then to the fish tank, then split across the GBs, then back to the sump, to keep some flow going through the FT.  This is going to require more plumbing than before, but this way I can use a simple timer, pump & IV setup.  I still need to estimate if I can get enough flow through the FT and also give the GBs enough time to drain the FT water that has been split to them, before the next one starts to fill.  Sorry if this is confusing, it's hard to describe in text.

 

One issue though might be that one of the cycles I want from the indexing valve would be to feed a few towers.  The indexing valve wouldn't need to be at the highest point of the plumbing, would it?

 

I was also wondering if the indexing valves have an option to connect polypipe directly to them, rather than PVC.  I'm hoping to avoid PVC plumbing if I can.

 

Also, if I want to run my system on constant flood, can I simply take the mechanism out of the IV to open all of the outputs up, or will I need to design in a bypass for that situation?

 

Thanks!

[TCLynx]

you might look up the CHOP 2 design for more flexibility in your design.

I would suggest though that perhaps a separate pump feeding the fish tank and DWC to run constant and a pump on  a timer feeding the grow beds might be easier.  I like constant flow/aeration in my fish tank personally.  If you are running a strong enough pump it is possible to have some of the flow going constantly to the fish tank and DWC beds while a solenoid valve could turn the flow on and off to an indexing valve feeding the grow beds.  I have never done this type of install personally though and it would definitely take a stronger pump than my usually set up.

 

The indexing valve itself does not need to be the highest point, however if you are going to pull out the stem/disk to run constant flood, you need to have the outlets very even in order to get even flow out of them.  If most are a grow bed height and one is up for towers, the one that is up won't get any flow when running without the stem disk unless your pump is huge.

 

The valves are designed for pvc pipes to fit into them.  I don't know of any poly pipe that is the exact right size or if the glues would be compatible, I just don't know this.  I would probably use a PVC street elbow and then adapt to a fitting that would work with the poly but, Small poly pipes will create lots of friction and reduce flows so I don't like to use them in my systems since I'm trying to get as much as possible from my pumps with the least amount of strain or energy usage.

 

Greener said:

Thanks TC, your advice is really appreciated.  I had seen your automated valve before (impressive!), I guess I wasn't putting it all together though.  Anyway thanks for the reality check.

 

I'm now thinking a better setup for me might be to adjust the flows so that I can connect the pump (on a timer again) directly to the indexing valve.  On every flood cycle most of the water would go through the indexing valve, and then to a GB and back to the sump, but the other bit of water would go directly to the DWC tanks, then to the fish tank, then split across the GBs, then back to the sump, to keep some flow going through the FT.  This is going to require more plumbing than before, but this way I can use a simple timer, pump & IV setup.  I still need to estimate if I can get enough flow through the FT and also give the GBs enough time to drain the FT water that has been split to them, before the next one starts to fill.  Sorry if this is confusing, it's hard to describe in text.

 

One issue though might be that one of the cycles I want from the indexing valve would be to feed a few towers.  The indexing valve wouldn't need to be at the highest point of the plumbing, would it?

 

I was also wondering if the indexing valves have an option to connect polypipe directly to them, rather than PVC.  I'm hoping to avoid PVC plumbing if I can.

 

Also, if I want to run my system on constant flood, can I simply take the mechanism out of the IV to open all of the outputs up, or will I need to design in a bypass for that situation?

 

Thanks!