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Comment by Lloyd Booth on June 25, 2014 at 12:03pm

Morning Joe,  I guess some more information would be useful.

>.. We discussed lift yesterday, so from the lowest level the water gets in your water source ( not from the pump) to the point where the water comes out to fill your growbed in inches and only vertical. (Long runs at an angle do add resistance, but for just now thinking height.)

>.. How big is your growbed in cubic feet (length by width by height to the level where the drain triggers), if your bed is small, do the math in inches and convert after you have the total in inches.

>.. How big are the pipes delivering the water? is there a decrease in width between the pump and the delivery of water to the growbed? (Example: I use 1 inch PVC pipe until I get to the delivery where I reduce it to 3/4 inch, add the faucet, and have a short length of 3/4" coming out of the faucet to reduce splashing (over the side, and out of the system). So, over all, 1 inch pipe to the delivery point, and then reduced to 3/4 inch.)

>.. And, how big is your pump? Usually these are measured in gallons per hour, but there are other measures also.

Those four pieces of information would help us visualize you system. I hope you are having fun with this project, most of us do it just for the fun.

Comment by Joseph Michael Martino on June 25, 2014 at 9:39am

hey all,

just timed out the flood and drain; looks like it takes about 1-2.5 minutes to drain and 4 to flood. how does that sound to folks? i do know the water levels, once drained, are well below the root lines. should i reduce the speed at which my pump delivers, or should i relax?

joe

Comment by Joseph Michael Martino on June 23, 2014 at 5:51pm

So here is what I am hearing;

If you are working with automated drain systems, timing is not necessarily the most important, that in fact there is a spread from a 15/45 min ratio to something more along the lines of flood/drain every half hour or even 5-6 hours.

The factors that will determine flood and drain are the location of water bodies and the volume of those bodies, which will determine pump size.  

Lift (head height?) is determined by taking the measurement from the top of a full body of water where the pump is located, whether that be sump or fish tank, to the top of the grow bed.  

Jim mentioned that his beds flood and drain about every 20-30 minutes; mine may be faster but I havent actually taken the time to time them out yet.  Are there major drawbacks to something faster?  I would imagine the roots dont have time to breath and the microbial life are negatively affected as they have similar oxygen requirements.

Short answer: yes it helps but I will always probably have one more question!  Thank you for your input, any advice on the above listed question?

Comment by Jim Fisk on June 23, 2014 at 4:20pm

Lloyd, keep in mind that the lift is figured from the surface and not the pump location. In other words my sump is buried below grade and the pump is on the bottom and my full IBC FTs are up on a cribwork of garden ties making the tops of them them about 9 feet above the pump. But if the sump is say full, or close to full,  the actual lift is only about 5 feet. Often misunderstood so I just wanted to shed some light on that.

As to timing Portable Farms uses timers and if I am reading their blogs right, they flood only 2 times per day or every 12hrs. I use siphons and I would guess they flood and drain every 20 -30 minutes. SO there seems to be quite a variable there.

BTW my pump has shown no change in flow in 2 1/2 years now pumping my 2500 gal system. I pump thru 1" S&W thin wall pipe and I believe the faster flow keeps it clean in there. I personally don't believe in over sizing pipes as the slower flow will allow for growth in my experience. I try to size pipes appropriate to the flow and avoid any "slow" spots. I know others disagree but it has been working fine. Also remember that for gravity flow from the FTs to the GBs it pays to stay 1 1/2" (in my case) or larger because sweeps (gental 90s and Tees) are only available in 1 1/2" and up. I discovered that the hard way some years ago after plumbing in 1 1/4" starting out. (but I already had plenty of 1 1/4") Had to change it all to 1 1/2" later on so as to increase the flo...

Comment by Lloyd Booth on June 23, 2014 at 2:23pm

>.. Timing is not so critical with self-activating drain systems. There are systems that fill and drain every 30 minutes, and those that fill and drain every 5-6 hours. Research on earlier models of hydroponics (back as early as Roman times) has shown that plants can do well will a highly variable flood and drain rates. 30 minutes and 6 hours are the extremes of the spread, I have found.

>.. Depending on how you arrange water location (height of lift) and how you arrange it (pump versus air-lift), the flow rate should flood the bed at least every 6 hours, probably not more often than every 30 minutes. The lift requirement often determines the flow rate. By example, my system has tanks for the fish below the beds for the plants. The mean lift is 7 feet. To achieve that I need a pump that will lift to that height. 600 gals per hour is the most reliable, but 450 gals can work, most of the time (depending on how full the overflow tank is). Less than that does not lift high enough to get water to my beds. Other members have the tank(s) on the floor of the greenhouse, and may have a lift of only 18-24 inches. They can use much lower power and lower volume pumps to get a much slower fill and drain frequency [AND use much less energy]. The biggest problem is that pumps are not variable; and they find increased RESISTANCE over time as the pipes get lined with forms of algae.

So, in summary, where you locate your tank in relation to your bed can determine what your flow rate needs to be. The other factor is the TOTAL volume of your beds. If you have 150 gals total water available into ALL your beds before they drain, then how much you pump per hour will give you your flood and drain frequency. Adding more beds and leaving the pump alone can decrease your rate of flood and drain again depending on actual volume lifted.

DOES this help you?

Comment by Joseph Michael Martino on June 23, 2014 at 11:52am

Hey all! I have a quick question!

So Ive been reading around a few forums and I find a lot of different thoughts on flood and drain, but here is what I believe is goin on.

Flood and drain is broken into two categories; constant flood and drain/timed flood and drain, and within these, are methods of returning the water to the sump or fish tank.

Constant flood; pump is constantly running, no timer, auto siphons or a simple standpipe. The standpipe however will typically require someone to actually time the cycle, in which case they put a timer on the pump.

At this point; if you are running a constant flood system with auto siphons that are working properly, do you still need to have the system run on a 45 min flood/15 min drain?

Thanks for the input folks.

Joe

Comment by Linda Logan on May 14, 2014 at 4:43pm

Hey Chris,

talk to Vlad, a moderator on this forum.  He has talked about a timer that will do that.

Comment by Jim Fisk on April 22, 2014 at 5:47am

Interesting and true all over the US. Our Trout come from rolling streams and never see the lakes. I have heard no such reports of the mountain streams being contaminated. The TVA lakes are showing levels but so was Moosehead Lake in N. Maine as well as Lake Winnipesaukee, both where we have lived. Lakes tend to concentrate heavy metals.

Personally I am far more concerned with rain water due to the blatant and obvious chemtrailing ops that are dumping unreported millions of tons of aluminum, barium and strontium into our skies daily. My system is in a GH for just that reason among others. I figure at least a portion of our food will be uncontaminated for now.

Comment by Lloyd Booth on April 21, 2014 at 6:16pm

Note: 04/21/2014 There was a large NPR report on lake fish in many National Parks revealing mercury. Have you tested your water for mercury? If you have tested, and no mercury, then you have a huge market advantage. Just a thought.

Comment by Jim Fisk on April 19, 2014 at 6:47pm

Great Maureen, good advice and thank you.

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