Backyard Aquaponics
A place to discuss aquaponics

Hi TCL. I think this second style of venturi would be the best one for me. The less I mess with piping underneath the better. Is the upright length of the pipe capped at the top or just left open? Probably open. It seems that the water fills to the verttical pipe and then starts trickling out. Is there enough suction to draw off the solids? Probably depends on how fast the return water is pumped back. Can I sit it at the bottom of the pond with little cutouts in it - like the 2 pipe venturi design - or must it hang from above? It looks like this venturi would be a lot easier to clean if got blocked. But it does look to me like the 2 pipe - one inside the other - would cause a faster flow and remove more solids. What do you think? Thanks for how helpful you have been. Chelle

Yes cut outs around the bottom will work for the pipe of either types of venturi drain.

I'm not sure exactly which one works best since my only venturi drains are on my aquariums and I don't have any holes in the sides of the aquariums. I have one standpipe, hole out the bottom venturi drain and it works fine. I also have a few no holes overflow venturi type drains. (problem with no holes overflows is they can get a bubble and stop working so need to be checked regularly to clear any air build up in the top bridge pipe.) I can say that since I added the venturi feature to the no holes overflows, the aquarium bottoms have been cleaner.
Here is a thread where I just posted some pictures from my aquarium no holes overflow venturi drains.
http://backyardaquaponics.com/forum/viewtopic.php?f=8&t=4086

As to backup for power outtage, I have a really good Deep cycle battery hooked to a charger and an inverter along with a circuit that will turn on my air pump (that is powered by the battery/inverter) if the power goes out or it will shut off my water pump and turn on the air pump if my water level in the tank drops too low (thus protecting my pump and the fish in that tank.) Another option might be a small pump that could keep some minimal water flowing and aeration happening running off a battery. I think we paid about $105 for the really good AGM battery. Another $50 or so for the really good charger that can handle charging that kind of battery and make sure to get a good power inverter since I found out that even though it might say rated for 100 Watts continuous power, the really cheap inverters only mean 100 watts continuous power for maybe 20 minutes at a time. I wound up spending a fair amount on the air pump since it is able to deliver 2 CFM (cubic foot per minute) at 2 psi and uses between 50 and 60 watts to do it. It is fairly quiet and already rain resistant (so long as not submerged or anything like that.) I figure I can run at least 20 hours of air on the battery before I even reach the half way drained point with the battery. I know it has worked for at least 14 hours before when something tripped the CGFI circuit while I was out of town and the neighbor was watching things. I have now put the feeders on the same power feed with the pump so if for some reason the system switches to air power, the automatic feeders won't keep adding food to the system. The main thing is to provide enough aeration for your stocking density during a power outtage. If you don't have many fish for the tank space, they might not need anything. If heavily stocked, your fish might be in danger pretty quickly without some sort of backup.

Sorry for rambling so much back to your questions,
The plants can handle some time without flooding and draining. Only danger is if it happens to be during a really scorching hot time, the plants could wilt and dry out a bit but your bucket method could certainly save them. Might be no need for the valves thought depending on the set up. You are more likely to have issues if the pump shuts off while the beds are almost full but not yet kicking in the siphons but most plants will survive wet feat for 12 hours or a day till you can let it drain and sort things out.

I enjoyed your ramblings. Hearing thoughts on problem solving help shape my design all the time. I am hoping to go quite big in the end to supplement income.

I was wondering if this CHIFT PIST design could be done in series..... FT to GB to FT to GB to FT to GB to SUMP. Venturi from FT to GB and loop siphon to next FT and so on until reaches SUMP below.

I was interested in your thoughts on alternate back-up power because I would like to run this whole series on only one large pump from SUMP to top FT and if possible do it with wind or solar power... stored in big landrover battery or batteries... still researching...... with maybe the pump working on a timer to get the flood and drain optimal.... (I know the stop-start of teh pump motor shortens its life but don't see another way unless the system itself naturally causes this to happen as it works its way down teh series of AP units)

I have a basic pic of what I want to do but don't know how to upload a pic into this message. Pressed "Img" and just gave me some HTML but no upload source to draw pic from. Different to what I'm used to.

Thanks again TCL for wonderful patience in explaining. Newbie questions must be a bit obvious to the experienced but when still building foundational knowledge every quesion is just a missing brick in the wall of understanding. You explain without assuming anything. I really do appreciate it.

When you use the regular reply button to post messages, there should be a upload attachment area below the first set of preview sumbit save and cancel buttons. You can only use the img function if the image is already on the internet, then you can simply put the url of the image location into the img tags. When you upload attachments, make sure they are only like 800 x 600 so that they will fit in the screen and not cause everyone to have to scroll sideways to read the threads.

As to the alternating fish tank grow bed design, sure it should work, provided you have enough height or slope to do what you want. Remember that each fish tank needs to be lower than the previous grow bed and the grow bed after the fish tank needs to be low enough for the venturi drain to drain into it. It would probably require a really big sump tank to protect your pump from running dry if for some reason the beds all wound up just trickling over their siphons rather than kicking in properly. Getting the flow rates right might be tricky but perhaps this would make a good situation for flouts since they don't need a specific amount of fall to kick in/out and they are not nearly so picky about flow rates. Perhaps if the grow beds moving down the cascade became a little smaller each time, you would be more assured of the previous growbed's "drain" filling and kicking off the next one down. This can be tricky though since the actual water volume of grow beds will change over time as roots grow, plants are removed, solids build up, solids break down etc.

I think my future plans will have a system where the fish tank venturi drains down through a grow bed which drains into a sump of sorts where the pump is. The pump would then pump the water up much higher than the tank into grow beds that will probably cascade into more growbeds before feeding a waterfall tank (pump would probably supplement the waterfall flow with a little bit of a bypass) back into the main tank. I just need to sort out how to have a sump in ground in a wet climate when the fish tank is going to be at least part way in ground too. I'm pondering something of a partially gravel filled bog of sorts that is huge enough that it can abosrb the fluctuations of the system with some water volume to spare for the top up valve.

Thanks for how-to on posting pics. I will be sure to resize.



I think I do have enough slope for CHIFT PIST. I want to use what I have in my hand and it seems a waste not to use the slope. I am drawing it up on sketchup and it appears to work. I just want to finish it and then will post it in the member system section. When I start to build - which is not to long from now - I will start from the bottom and work up. Build first the sump and then the GB's and fish pond as a unit. Even if the final units needed a little extra boost in height I could always just build them a bit higher. Hope I wouldn't need to but not impossible.



Do you think the sump tank has to be the size of all the proposed GB's or just the final GB's. Would the fish ponds in between not be enough in holding the water? You have raised an important point.



I have never heard of a flout before so will make work of looking into that.



I want to give 2 to 3 loop siphons to each growbed to ensure rapid exit of the water to the next fish pond in series. I could always block one siphon if too fast. My first unit will teach me a lot. Root crops hate to be too wet so they could be placed here in final design completion.

Yes, the tweaking of the flow and drain gets exponentially more difficult the bigger the project gets. Many variables to be considered.



This sounds really neat. Very high DO would result and excellent filtration. Are you not concerned that maybe the plants at the tail end would suffer nutritionally? It depends which is more important - fish or plants I suppose. I will be interested to see this if you choose to go ahead. I was unsure why you were concerned about a wet climate with sump and tank lowered into the earth. Flooding?

Thanks again for all your help. Hope your weekend has been good. I think I will get started on loading my proposed system in the Members section now.

The nature/point of sump tanks is that they are not always full. Think of a mostly empty container sitting in a hole in the ground, what will happen if that hole fills up with water outside the mostly empty container? Container will float, perhaps forcefully enough to break plumbing lines. Has happened to members. A really heavy container, like a poured concrete tank, will be far less likely to float but remember that they do make ferocement boats too.

I've also run into issues with my monster grow bed that is on the ground, lined with pond liner. We had a huge rain event and there were several inches of water all around and the bottom of the liner was trying to float up under the sump pump switch forcing the pump to stay on even when the bed was mostly empty, nearly burning out the pump.



Remember that the fish tanks in between if set up CLIFT with venturi drains, will not absorb much fluctuation. I still think you will want a big sump. One of the common issues people have with sumps is they often make them too small. Many people with systems running more that one pump, the sump is just a place to drain the beds into before pumping it back to the fish tank which has a pump running the water from there back to the grow beds. What happens when the power goes out just as the siphons in the grow beds kick in? The sump overflows. IF the sump tank were big enough to hold all the water from the grow beds, there would be no problem.

Never count on the grow bed siphons never aligning.

Now in a cascade set up this should not really be a problem in theory but I no longer trust theories about water flow when roots, frogs, rocks, snails, leaves, small fish, or anything else natural is involved. I've had baby tilapia swim through a grow bed before and wind up in the sump while others continued on through the pump and up to the other fish tank. No telling how many of them died in the gravel rather than being eaten by their brothers/sisters.

I doubt you really want to do multiple siphons off of one grow bed, I could be wrong on this but I don't think it would cause the bed to drain any faster since I expect that one siphon is likely to kick in before the others and the bed will just drain through that one. The other siphons would just be complex overflows and might function as siphons if the first one were to completely clog, so I guess there might be some merit to the idea since I strongly encourage always installing an overflow pipe.

As to the Fouts, there are several mentions/discussions about them. It stands for floating outlet. A container floats up bringing the flexible pipe with it, when the water is high enough that it finally rushes into the holes in the container, the container sinks and the water rushes out the pipe, once the water level is low enough, the container sucks in some air and floats back up. I made mine out of a cheap sandwitch container, some flexible sump pump tubing, a few fittings, and aquarium silicone. It still leaves some water in the bottom of the bed but so do all the siphons. The big advantage of the flout over a siphon is that the flout will kick in once the water level is high enough, no matter the inflow rate. The only flow rate concern with a flout is that the water can't be flowing in faster than the drain pipe can carry it away by gravity. Works like clockwork! There are only two big drawbacks I know of with flouts. 1-They are a little more involved to build or adjust than a loop siphon.
2-They take up more space to function since the container and pipe need to be free floating

Makes sense. Can see your concern now.



OK. Rather safe than sorry.



Good point!



Yes. Has been my experience in other things. Theories are not enough. Amazing about the baby tilapia. How could this be prevented?



Of course! Needs topped GB to initiate suction! Experience shows again.



Very interesting idea. Worth considering. Thanks so much.

Hi all, I've just started getting interested in aquaponics and researching how it all works. So far it all looks very doable even for me

Ive been reading through this thread about the CLIFT PIST set up and was just wondering why its necessary to have the sump in the system.

Why wouldnt you pump water from the tank up to the grow beds to flood them and then let it drain directly back into the tank?

I'm trying to see where the disadvantage is but can't find it myself.

Sorry if this has already been discussed, i've really only skimmed the surface of this site at this stage.

A sump is required to level out the heights in the system, depending on system design / site requirements.

My large system has no sump. The small system does.

Only real advantage of a sump is the water is usually cleaner, and the pump requires less maintenance.

Thanks for the reply, So how big is your large system and how small the small?

I can see now that the fish would get pretty cramped if half their water kept getting pumped out to flood the grow beds before it drains back in.

Makes a lot of sense now that i think about it.

Thanks

Nice system OBO! Must be great to just be able to dig down a bit - throw in some liner - and fill it with water. Like slicing through butter.........

OK! OK! Got it.... was a tough job. Nice job too. Really neat.

heh lol

Am about to do it all again for tank #2

keeps me fit

fit?? from digging that sand?? LOL come to digging bootcamp melbourne

Hmmm, wet heavy clay, with besser block sized rocks mixed in.....