Adjusting water flow into grow beds and bell siphons

[Deborah M Espie]

I have slowly been cycling my system since last October. I have a total of 5 grow beds but added them one at a time. Now that they are all in circulation, I find that the last two I added fill VERY slowly and as such are holding water from the system. (it's a CHOP 2) so my sumps are often out of balance in terms of volume, not that it bothers me expect that if a bridge siphon were to malfunction I could have a flood.

Also I find I'm adding water to my system at least once a week. In northern NM so humidity is very low.

I was told that once I had the bell siphons adjusted with water flow so they were charging and discharging to just leave them alone and not worry about how long it's taking to fill the bed. Is this correct or should I fuss with water flow and get all the beds filling at the same rate.

2nd question, is it normal to have to add 10% water once / week in a very dry climate. Fish (Rainbow Trout) don't seem to mind, eating fine and no deaths since October.

[paul burton]

How have you set up the discharge cycle. They should not all fill together, or drain together.
5 beds on a fifteen minute cycle. Each bed needs to start draining 3 minutes after the last bed.
How big are your beds/sump tanks.

[Brent Shafer]

Def normal to have to add water -- lots of evap from low humidity --10% not unusual. Not sure how to answer your other question except generally all the beds will eventually cycle together, occasionally, so your sump tank and FT need to be able to handle that volume without going dry. 

Bell syphons need to be adjusted occasionally due to various factors as your system ages.

[Cindi Conway]

Deborah, I have 35 1/2 barrel beds that operate on their own timing. I have found that all I have to do is look into the siphons each day to check the water levels. If the water is somewhere in between the top and bottom of the drain, it tells me it's working correctly. If the water is at the top or bottom, I watch for a few seconds to make sure its working, and only adjust if it's not right.  The only time water level in the tanks has been an issue is if the main pump has been off. (As when I'm cleaning it)That causes the beds that are in the draining process to fill at the same time when the pump is back on. Then the next time, there are too many beds emptying at the same time which can overwhelm the sump. By only adjusting water fill in beds that are "stuck", The beds are draining very randomly which keeps the water levels in the tanks at a consistent level.

Also, as long as your beds drain quickly, that pulls the oxygen down to the roots which makes up for the beds filling slowly.

[Deborah M Espie]

Thanks Cindi, Brent and Paul,

Looking into the iPhone is how I have been monitoring, didn't realize I should have them on a pattern.

Mostly concerned that plants in slow to fill bed are drowning.

[MikeH]

I have 4) 12cu ft grow beds (4'x3') and am about to add an IBC GB to it. I am also running it as a CHOP2 system. I was running as a CHOP system but found that I was pushing too much water through my FT. My GB's drain at differ times between 17-20 depending on the bed. I am using 2) bottom halves of IBC as sumps. They are connected via 1) 1" line & 1) 1-1/4" line. Sometimes my GB fire off at the same time, sometimes they don't. My system is kind of a hybrid (I guess): GB & DWC & adding 3 NFT tubes soon.
As for adding water, I hear that is typical of all systems, amount depends on climate where your at. My system total is close to 750 Gallons and I currently add about 30 Gallons a week and will estimate my summer consumption to be about 50-70 G per week. I am in So. California.

[Deborah M Espie]

LOL, somehow autocorrect turned "bell siphon" in iPhone? Wow

Looking into the bell siphon is how I have been monitoring, however, there is one grobed that is taking, imo, too long to fill. I will try to get them timing as Paul suggested and see if I can't get them all filling at the same rate.

[paul burton]

If your beds fill at the same time, as the water level falls so does water flow. The weight of the water flowing back into your tank helps keep flow up. Also it helps keep the water level more constant if you have fish in there. Some water will be lost to evaporation (keep sump tanks covered or in shade if possible), and plants will take up water as they grow don't forget. 8-) 10% isn't much.

[paul burton]

Video off you tube https://www.youtube.com/watch?v=K1w4lWVtERQ
How to tune your bell syphon

[Jeff S]

I don't think it matters how long it takes to fill your bed as long as the siphon works and  your FT cycles at least once per hour. The simplest way to address multiple GBs is with a large enough sump to eliminate any problems.

[Brent Shafer]

 my research suggests that 15 min fill/drain cycles for 10 inch water level media/rock beds is the target to achieve optimum nutrient/oxygen ratios. 

[Zach]

What is the majic size and distance from pipe to bell on a siphon to work right? i't been a practice of stubornness trying to get it to be consistant.

[Brent Shafer]

I use a 3/4 inch stand pipe with a 1 inch expansion adapter on top with a 1/4 inch v notch cut into the lip. its abouit 1 1/2 inches from the top of the bell. the bell pipe is 2 inch. all surrounded by 6 inch pipe with horizontal slats ax water inlet to the bell area