Backyard Aquaponics
A place to discuss aquaponics

Dear all,

This is the system I'm preparing to build:



(My pond has that T shape. I didn't want to dig more, instead used some bricks to finish the job by rising the pond)

I'm unsecure about a few things in my project, so I find it best to ask here before starting to build:

1 - My fish tank (pond) and growbed are located in opposite sides of my backyard. This means I will have 2 pipes 5 meters long each buried, for this reason I'm worried about the diameter of the pipes, regular maintenance/cleaning won't be possible. At first glance I don't see any con by going big. I was thinking about 75mm or 90mm. Will this size be hassle free forever?

2 - I think the best place to have my pump is after the swirl filter, submerged on a 10L bucket or so. From there the water is pumped to the GB. What do you think? Any cons?

3 - I will need to open a hole in the liner of my pond in order to have one pipe passing through. How can I seal this opening once the pipe is in?

What do you think about the design in general?
I want to build a reliable, hassle free and micromanagement free system that I can run on a long term.

Thanks.

Hi Pedro,
your design looks ok but you'll need to consider some issues.

Running pipes underground is very convenient as far as traffic is concerned but if you're not to keen on digging (who is?) your pipes might end up with very little soil over them. This can lead to unsightly track as you try to regrow grass over it, also a loaded wheelbarrow may damage the pipes in wet weather.
Pvc 75 mm Storm water pipes are cheap for their size but are thin walled whereas DWC are thicker and have the most types of fittings. Pressure pipes are very strong, have less fittings and are most expensive. Some times you'll need to mix them to get the seal or fitting train you want.
You might want to put the filter closer to the outlet of the FT where the solids are still suspended in the water exiting and the pump after that. Unless the flow rate is very high muck can settle in the bottom of a long run pipe. I'd recommend installing an inspection pit/opening at each end of a long under ground run. it's more work but it's much easier to see or be able to feel for a problem than imagine it.

Hey Pete, thanks for your advice.

True, cheap PVC pipes usually used to catch rainwater are fragil and can crack easily. However all the other thicker pipes go only up to 32mm, that's what I found in garden shops where I live. But yeah, now that I think about it, it might be worth to keep looking, I can see the difference it will make in the long term. Really nice that you stressed that point.
The pressure pipes you refer to are made of PVC as well, right? Concerning the diameter, I might go for 75mm, 90mm might be a bit overkill for 2000L system.

You are right, the filter next to the FT would separate the waste before it goes into the undergound pipes, thus reducing the muck on the inner walls of the pipe. The only problem I see is adding more pipes and curves. Will think about that.

I can't picture in my mind how a inspection pit would be. The water level is higher than ground level, so exactly where are you suggesting to build it?

For cleaning I came across these two possibilities. By introducing an hose inside the pipe and use full pressure from the water grid. Or by introducing a flexible but thick wire, 1.5mm or so, with steel wool attached on the end.

Over here PVC sewer pipes (a light yellow colour) are the go between storm water and pressure pipes, and being used for muck that can clog they are available in the larger diameters with lots of fittings and adaptors. The other benefit is the bends and T's come with sealed screw on I/O's (inspection openings). Look up plumbing and rural plumbing suppliers in your area- ask for an account or trade discount. It wouldn't hurt going for a 90 mm sewer because the the larger the pipe the larger the bend radius and less restriction. Don't clean with steel wool use a bundle of shade cloth or similar, something non abrasive.

Inspection pits are usually concrete or plastic boxes with a lid at ground level. They give instant access to plumbing junctions and or pipe work. They can be purchased a the plumbing supplies or made yourself. So in your case you could have one at each end of the long run to access the I/O's in the sewer pipe.

The pipes will need to be reduced at each end to accommodate pump fittings, valves and GB dispersion pipes, pvc screw couplings are a good idea with the smaller sizes - if you put them in you'll rarely use them if you don't you'll end up cutting and shutting more often.
You'll need to have at least 300 mm fall in the GB - FT outlet otherwise you'll have the GB flooded higher than you want due to not being able to get rid of the water quick enough.

That may be because garden shop customers don't need anything bigger than 32mm

I regularly buy heavy walled pvc pressure pipe and the shop normally has everything from 20mm to 300mm in stock.

If I need more than about 500m in the bigger diametres I have to wait for them to order it in overnight

I'd be surprised if there aren't similar suppliers local to you, try asking at some major plumbing suppliers. If they don't stock it they'll know who does.

A company who makes these types of pipes in Australia is Vinidex

I believe Vinidex has a presence in Europe, not sure if they're in Portugal (but I wish I was, nice place!) and not sure if they deal in pipe over there or just the fittings.

Fantastic discussion. Do you need a sump tank for the pump to sit in?

Hi Pedro, welcome to the forum. I have a 3000L system with 3700L of media growbeds. I have mostly underground plumbing but I only use 50mm for the return and 25mm for supply to the GBs. I know larger pipe seems like a good idea, and it is in many cases. But with larger pipe the water velocity is reduced and solids will settle more easily. I have not had any issues with the 50mm return lines in the past year since I built my system. I did have to flush one of the 25mm supply lines recently as I noticed reduced flow to the far GBs.

For cleaning, I recommend a cleanout at each end of the run. That way, by simply unscrewing the cleanout cover you can access the straight run with a hose or any other cleaning method that works for you.

I also recommend putting the solids filter near the FT, before the long plumbing run. This may be a challenge in your situation (no matter where the filter is located) because your FT is very low. You will need about a 150mm minimum drop between the FT water level and the filter water level. I recommend a RFF, not a swirl filter.

Lastly as the water level fluctuates up and down from evaporation, clogs, flow issues, etc. the water level in the filter will vary too. If the pump intake depends on the overflow from the filter, be very careful that you don't create a situation where the pump is sucking air and stops moving water. I recommend a barrel with the same depth as the filter, so hopefully the pump will always be submerged and there is always enough water in the FT to be sure there is filter overflow to the pump - perhaps a float valve in the FT for top up water?

Lastly, if you are running CF, then what happens when the power goes out? Many CF beds will have a "weep" hole at the bottom of the standpipe so water will drain back to the FT if the power goes out. I think your system will need to be sealed so if the power goes out ALL the water will remain in the GBs.

I run a similar system without a sump tank. I draw water from the FT with a 50mm pipe, pump it to a RFF with 40mm pipe. The RFF is the highest point in my system. The overflow is also 40mm and that feeds three different 25mm pipes to supply different sections of GBs. The GB drains (flood and drain) are 20mm but feed into a 40mm "lateral" that then feeds a 50mm return to the FT. Everything is buried except the pipes to the RFF (20 feet away - added later).


EDIT: By the way, it's generally a bad idea to pump to the filter (for RFF / swirl) as it grinds up the solids. Mine happens to work reasonably well since I have a large volume RFF compared to the flow rate, so solids separate very well. I put a filter pad under my GB inlets so I can see when solids start to pass to the GBs.

All my plumbing is imperial, converted to metric so the sizes may not match available pipe, but you get the general idea.

A few years from start up and my 90mm drain was blocked by roots from an outside source. PITA!
Drain Waste Vent (DWV) pipe does have thinner walls and is cheaper but is also flexible. It is not under pressure. You do not need to pay extra for pressure pipe. Apart from the blockage of roots, caused by my pitiful gluing effort, I have no build up whatsoever. The drain slopes downwards slightly to the sump. Provided there are no vertical rises there should not be any solids build up unlike the supply line which needs velocity to move the solids up the vertical risers. I'm not saying smaller drain pipe won't do the job as it clearly does but I can pull the stand pipes out of all my beds and have unrestricted drain flow. (2000l)
Having a tee inspection pipe at regular intervals is something I recommend on the pipe work and a drain valve at each low point of the feed line for clearing settled solids.
Underground is neat and tidy but it does need planning as is difficult to modify if under pavers and the like......

Hey Guys, I was wondering if Pedro could put the RFF in the FT at the appropriate water level, place the pump either in the FT or outside in a pit and suck through the filter?

Hey, thanks all for your input and ideas. I was out of town for a few days, couldn't reply sooner.



In the meanwhile I found the diameter I needed in local suppliers but the prices more than triple... Since I'm not willing to pay that much for pipes, I went to a local garden shop and noticed they have two types of PVC pipes, 1,5mm thick and 3,2mm thick, the price varies 10% only. The 3,2mm doesn't have the PVC pressure ISO label but since it's quite thick I wonder if it won't be enough for my needs. Do you guys have any idea how thick your PVC pipes are?




Ups! Since I have a weak pump I was planning to have the GB just slightly higher than the FT, more specifically, a 100mm fall from the bottom of the GB to the FT, hopefully with enough speed to splash / oxygenate the water. When you refer to the 300mm fall are you considering the top or bottom of the GB as a reference?




The FT is below ground level, can't have a sump lower than that.



Not new to the forum but thanks anyway . Ok I got it, it's due my noob questions.
Yes, it makes sense but how do I know if my pump is strong enough to move solids with a 50mm pipe? My bet is that with a larger diameter chances of clogging are reduced.



Ok, did some research on RFF. Indeed, seems better option.
Can't picture exactly where is the 150mm drop needed, as you mention your RFF is higher than the FT.
Based on your system, I came across a diferent design that might address some issues that you and other participants in this thread stressed in previous posts. However this implies having the pump in the FT, thus possibly grinding the solids before the filter.





I guess I can have a hole at the bottom of the standpipe without any issue. My 550L GB fills with 180-200L of water, my FT has enough room to take that load. My FT is 150cm x 150cm, 200L adds 8-10cm on the water level. Hope my math is right.
Other possibility is to drill the hole a few centimeters higher.


Thanks all for your input. I'm sure this thread will save me lots of headaches in the future.

Start with a 2 in. Brass Foot Valve w/screen in the bottom of the pond
http://www.homedepot.com/p/Water-Source ... /203449587

Come straight up and do a PVC radius sweep going towards the pond wall, and a Union just inside the wall of the pond for EZ access Schedule 40 PVC 90-Degree Rigid Conduit Elbow With Belled End 2 in. Bend Radius 9-1/2''
http://www.carlonsales.com/techinfo/bro ... and_80.pdf

Carlon sells also the following, in degree's of radius
Schedule 40 Elbows Standard Radius
9.5'' Radius's in 90, 45, 30, 22.5, 11.25 Degree Radius's

Standard Radius Elbow Dimensions
Schedule 40 Elbows Special Radius 18'', 24'', 30'', 36'', 48'', 72'' Radius's in 90, 45, 30, 22.5, 11.25 Degree Radius's

After the Union do another radius sweep, and turn towards a Wye. with the top sealed with a threaded plug, for EZ cleanouts.

Do another radius sweep into the ground, run it over and come out of the ground with another sweep, going up to a Wye, with a threaded plug, for EZ cleanouts. Hook the pump to the Wye, with a 45 degree sweep and use a Union on both sides of the sweep for cleaning, and into a above GB Mechanical SS sieve filter.



Bottom of MF to the GB, and the middle of the filter to a MT or bucket for the solids.

On the exit side of the GB, install a Pool Skimmer, bottom set a the height of the AP water, and return to the FT using radius sweeps.
https://www.yourpoolhq.com/hayward-abov ... fgodppwE6g

Hydraulic Cement ? Uses and How to Apply
https://www.thebalance.com/what-is-hydr ... ply-845076

Hydraulic cement seals around the pipe, by swelling grabbing the pipe and walls of the tank. Use Iced Water for mixing in Hot Weather.
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OK I better comment on this before it gets around - Constant Flood (CF) does not have a weep hole in the standpipe! The whole idea is to keep the water level constant in the grow beds in order to keep the fluctuations in the sump or fish tank small. From the beginning they aren't designed to handle the extra water (although some still may be able to handle it). The fact that the CF beds do not drain makes adding grow beds without increasing the size of the sump or fish tank possible. That's one of the biggest advantages to running a system CF.

Flood and Drain systems have the weep hole because they have sumps that were designed to take that extra water and it allows the bed to drain between cycles.

Thanks, I'm aware of that.
I don't need the hole in the standpipe, but if my system is sized and prepared for it, it means I can switch to flood and drain later just by adding a timer, no need for any other adjustments. I would like to try both CF and FD.
If I decided to add another GB later, than the system had to be CF for sure since my FT wouldn't be able to take that amount of water.

In case you don't know - Make the standpipes removable and put the weep hole in one end but not the other, then you can just flip the standpipe to having the weep hole down and put on the bell siphon to switch.

The closer the pipes are to the surface and traffic areas the thicker they should be, I used 40 mm DWC 2.5 mm thick to transfer water from the GB SLO to the dispersion pipes on sys 1&2 just a few inches below the surface. The fall is about 300mm which is within the 15 minute on time.