Backyard Aquaponics
A place to discuss aquaponics

Wow that is too much switching. Your sump pump will be the weak point with it going on and off constantly. You should look for ways to slow things down a lot; larger sump, timer on the pumps, staggering the pump cycles to keep the sump continuous, stuff like that.

That is why I was thinking of a timer. The sump is already good size, its the amount of water going to the grow beds. Like I said, each pipe does not have alot of flow but with 2 2x3 beds, 1 2x4 bed and the long trough going it is alot of water. By the time the water reached the last pipe it is almost a trickle. Maybe I can cut back on the first 2 tanks.

Lowe's has the 15 minute timers for like $12-15 or something like that. I am using the one that is a power strip that has half the outlets on the timer and the other half not. All the timers I have seen in stores are made by the same couple of companies, and if you find one that has increments less than 15 minutes please let me know!

Joyce, How are you throttling your flow to the growbeds? Not sure if you have some adjustable valve in line or not, but if so your could adjust those and possibly divert some of the main pump output straight back to your fish tank.
Is your sump filling twice a min as well? If so, then I'd think that should work for you.

Dave, I checked at Lowes and they sent me to the water sprinkler section. No one seemed to think they sold them. What section did you find your timer?

John, I have ball valves above each growbed. The barrel in the tank was an idea from Steve as my bio-filter until the grow bed area was finished. I can always use that for extra water. The sump fills about 3 x a minute.

Hi Joyce:
They are in the lighting section, next to the little outdoor landscape lights. They have a small section of just timers at the stores around here. They are all variants from the same few companies.
When my 100 gallon system was set up with a sump, the sump pump would go probably every 15 seconds or so, but the tank pump only went on 15 minutes per hour.

I'd agree with you and Dave on the timer then at least untill you have your growbed area finished, bring that pump cycling down a lot. If you could divert some water straight back into the fishtank I'd also do that till you find a timer, would mean you fill the beds slower but dont think that will hurt.

I have the system set up as a trickle, not a flood and drain. Will that make a difference as to the amount of water need that goes through the growbeds?

I guess I'm a bit confused then. Your running two pumps, yes? The main pump on contuious flow? Then the beds draining to a sump and the sump pumping back to the fish tank? Thats how I have assumed you have your system set up. I dont imagine slowing down the flow would hinder you as long as the media remains wetted.

This is true, it does not take much water to keep things damp. That really is all we need, isn't it?

plus drawing oxygen through the gravel, and keeping it all wet so the bacteria survive

Joyce,

At this moment, I have to increase my grow bed space and finish my sunroof over the growbeds before winter sets in. I do have several unused glass and acrylic tanks lying about that will eventually house fry and successful couples (honeymoon suite). Your description of the Nile tilapia is correct. They have distinct vertical banding patterns on the caudal fin, particularly the males, and pink throats when sexually mature. Females tend to be a little lighter, but identical so I’ve had to flip them over to identify. Interestingly you have two opposite types of breeders. I would hypothesize that the Nile will be the more successful breeder in your system due to limited space. Substrate brooders have a harder time guarding nests in tank culture unless given ample space. Do you keep the two apart?

I solved my sump issue by getting a tank with equal volume as my grow bed space (250 gallons), that way if the pump failed I wouldn’t have a flood. Also I can truly flood the grow beds and allow them to completely drain before re-flooding, thus oxygenating the substrate. Also, the sump tank is big enough to rear fingerlings. My timer is critical to the system watering and oxygenation (I do not add oxygen to my system), and therefore I spent more money to get a good hydroponic timer (recommended, check out Greenfire Hydroponics). I am glad I did this, because I have very accurate control over the cycle depending on the plants and the flood levels of the tanks and beds.

Regards,
Mike

With all due respect, I started with the cheap light timers and as my system demands grew, so did my need to have precise control over the watering cycle. This is the timer I use for my primary pump. I am very pleased with the results.

http://www.sgs-hydroponic.com/product_d ... hp?id=1197

Hey Mike:
Nice timer, crazy expensive! Does exactly what I need. This kind of thing should be DIY-able, don't you think? (I'm actually getting out of the timer busines with version 2.0)

How long will it take for a tilapia to go from fry to plate size? I.e., do you guys think I should buy fry or fingerlings in January?

Joyce, I would think you could get the pump to turn on and off and still keep things wet enough/cycling. I guess this would be a timed continuous system then?

With all of this chat about pumps and timers, I'd like to contribute a couple of thoughts.

Cheap timers are designed to switch small electrical loads like lights and small aquarium pumps - I wouldn't use them to control high volume submersible sump pumps. Think about float switches or similar controllers as an alternative.

Submersible sump pumps are not generally intended for continuous operation - they are meant to cycle on and off. Also, if any part of the pump ceases to be covered by water they will overheat and burn out very quickly. If they are fitted with an overload switch, they will stop until you reset them. Either way, you may have a disaster on your hands.

For continous operation, consider a circulator pump or a centrifugal pool pump.