need help visualizing the MPB setup

[joehank]

I'm trying to understand how the drainage coming from the 4"( or what have you) pvc gets back to the main res. In my head I would think that - 1) the main res would have to be lower than the end of the drain pipe, or - 2) it drains back into another bucket that will then pump back to your main res. If it's #2, how do you control that pump?
If anyone has any pics of this portion of the setup please guide me to them. Thanks

 

[joehank]

ok I was just schooled on how this works ( ttystikk has alot of patience with me). I thought that the res was involved in the circulation part but it isn't. It is used to top off the other buckets in the system only, no drainage returns to it. This is done by using a float valve in another bucket that comes before your first MPB site. This " controller " bucket has to be the same size as the MPB sites so that the water will level out evenly, is that correct? So in this controller bucket sits the main 1800gph pump ? Does the drainage from the MPB sites return to the controller bucket fast enough so that the pump is not sucking air? Will there be problems with the float valve because the water in this controller bucket is unstable and moving around too much?

 

[Capulator]

ok I was just schooled on how this works ( ttystikk has alot of patience with me). I thought that the res was involved in the circulation part but it isn't. It is used to top off the other buckets in the system only, no drainage returns to it. This is done by using a float valve in another bucket that comes before your first MPB site. This " controller " bucket has to be the same size as the MPB sites so that the water will level out evenly, is that correct? So in this controller bucket sits the main 1800gph pump ? Does the drainage from the MPB sites return to the controller bucket fast enough so that the pump is not sucking air? Will there be problems with the float valve because the water in this controller bucket is unstable and moving around too much?

You are still confused.

In the MPB, all the buckets with your plants are higher than the main res. thats how the water drains back. Via gravity. No float valves in an MPB except if you are using one to keep your main res topped off. Do not PM me please. I will put pics here in your thread later today or tomorrow so you can get the full picture. Or you can go over to the diaries thread and see a full build in capulators first MPB thread.

 

[joehank]

I haven't pm'ed anybody, but ok. Yes a few pics would be cool.
That must really limit the choices for a res. I was hoping to use 55 gal drum as a res but thats not going to work

 

[tedsprogz]

I dont want to confuse you, but there 2 MPB styles also...feed from bottom/drain from top and feed from top/drain from bottom...the first of them allows for the res to be at nearly the same level as the sites(if the MPB's are tall enough and the drain hole are as high as the res). if you drain from the bottom you will have to elevate the MPB's. you can drain from the bottom and keep the MPB's at the same level as the res as long as the drain goes from the bottom of the MPB to the bottom of the res, but it wouldn't be very efficient

 

[joehank]

I think the first would be better, draining from top. I would think drain from bottom would get clogged easier. In the pics above of the 55 drum, when the system is in operation how high does the water get in the drum? It seems like water would not drain in to the drum well if water level was high, relying on the pump to kinda" suck " the water in from the drain.

 

[tedsprogz]

the water would never get higher than the height of the drain holes on the mpb sites

 

[tedsprogz]

generally the drain holes are at least few inches higher than the level of the water in the res so it creates a splash

 

[joehank]

in the example in the pics above, isn't that the drain return in the bottom of the barrel? I thought you would want it to splash into the res to create aeration, hence the need for the res being lower than the drain. I understand how the barrel above will not overflow because it along with all of the sites will level off at the height of the highest drains ( the plant sites). So the setup above is really relying on the pump, more than gravity, to force that water back to the res. One good thing about this setup is that the drain pipe, being so low, should be totally full at all times, not allowing any nasty stuff to grow in there.

 

[Capulator]

because the system is constantly running all the water never drains back. When you initially fill, you will fill your main res to the top, then fire the pumps up to start pumping water in to all the plant sites. Then, you start to fill the res again, until the water is coming back strong through the drain and in to the main res again.

In mine I copied the original MPB (medical patient bucket) by DD (with help from Heath). I have a 100 gallon stock tank for a res, and each site holds about 7 gallons of water. in total my system holds approx. 156 gallons (9 plant sites plus main res). My drain comes in at the top of the main res, and the plant sites are elevated about 2' off the ground with stands. the drains on the plant sites is about halfway up the bucket (2 x 1" bulkhead fittings). These 1" drains drop down in to a 2" pipe (DD used 3" I think but I like the 2" since the pipe stays full that way). The 2" pipe is sloped 1/8" to the main res. My feed lines are 1/2" and are coming in to the bottom as low on the side ofthe bucket as you can get a fitting. For 9 sites I use 2 x 1800 gph danner mag drives. I also use 1 1800 for the drippers.

The drains in the bucket are made so that the the net pot is just barely in the water. DD states that his water level is 1" above the bottom of the net pot.

 

[joehank]

really nice setup Cap, what is your ceiling height in that room? In your setup you can see the drainage flowing back into the res. In Thompsons, with the drain coming in on the bottom of the res it will be less noticable. That's why I think his pump is kinda " sucking" the drainage back into the res. Pros- res doesn't have to be lower than mpb's...Cons- maybe not the best circulation happening?

 

[Drdre]

The pump you see on the ground has nothing to do with the drain the pump on the ground is hooked to a 1inch pvc pipe for the feed so the pump pushes water to the tubs so that the tubs over flow into poly tubing that is connected to the abs which is sloaped so the water always drains back to his main res

 

[Drdre]

the drain is higher than the water leavel which is always causing splashing that is what causes aeration

 

[joehank]

right i get that, but his drain is on the bottom of the res. so gravity is not helping as much to get the water back. Especially with the water pressure of a full res " pushing" back in on the drainage. Thats why I'd say that his feed pump is working a little harder to force that flow. Obviously it works and allows for the res to not have to be lower than the drain, but I wonder about the aeration. Is it calm and swirling like the inside of a UC bucket, or does it not fill up too much so that there is somesplashing happening?

 

[joehank]

the drain is higher than the water leavel which is always causing splashing that is what causes aeration

So by looking at his res, that drain comes in less than 10 inches from the bottom. Your saying that it doesnt fill much past this point when in motion?

 

[Capulator]

In Thompsons system the buckets are low and wide, and are lower to the ground. The plant sites themselves are 70 gallons each. The barrel is much taller than the buckets. Total water in his system must be somewhere in the 300 gallon + range. On my system you need a check valve after the feed pump to keep the water from running back in to the main res (power outage/pump outage). All the water form the plant sites will rush back through the pump and over flow the main. If you had your feed lines above the water line, this would not happen. I believe DD did this in his later setups.

 

[Capulator]

really nice setup Cap, what is your ceiling height in that room? In your setup you can see the drainage flowing back into the res. In Thompsons, with the drain coming in on the bottom of the res it will be less noticable. That's why I think his pump is kinda " sucking" the drainage back into the res. Pros- res doesn't have to be lower than mpb's...Cons- maybe not the best circulation happening?

my ceiling is 9'. I have 6' from the top of my bucket to the ceiling. Giddeon runs an MPB as well and runs a 7.5' ceiling and has hit over 3# per site with the Recon in his first runs.

What I like about my setup is the height of the buckets. I have a roll around stool that I can sit on and comfortably access all the guts of the plant. I spend about 1/2 hour each site at least 4 times through the cycle cleaning out larf and dead leaves. I can't imagine doing this in a UC crawling around on the floor.

 

[Papa]

I dont want to confuse you, but there 2 MPB styles also...feed from bottom/drain from top and feed from top/drain from bottom.

i've never seen the second that you mention. 'have no idea how that could work. can you show an example?

 

[joehank]

correct, and the same thing will happen here also, but since the barrel is taller than the sites, they will all be at an equal level and will not overflow should a failure occur.
I see his containers sitting on 3 cinderblocks and a piece of wood, so about 25 inches from floor. Add 13 inches for tub and another 5 for lid, thats 43 inches to top of netpot. I only have 7 feet to work with, which leaves only 3 feet of vertical plant space.
I would need to get the sites lower and the far end of the drain higher to make this work for me. Possibly even feed the sites from the top...

 

[Drdre]

Now you understand how thompsons drain and feed works!