Backyard Aquaponics
A place to discuss aquaponics

ok sorry for the sound of frantic sound lol, i created an account and after a 2 wk wait i never got approved so i made another and seem to be getting nowhere searching online nonstop.

ok so i have a 300 gallon FP, sadly its square but its what I got, and using barrels cut in half as in pic. to start we have 4 GB's and will add more later. i will try a siphon later but was gonna just do flood N drain for now to get it going cheap and faster as we only get a short 3 mo. summer here!

ok so my big questions:

1-what is a swirl tank / filter and do i need one? if so how should i plumb it in, and basic pipe size?

2-should my flood lines into my beds dump into top or be plumbed into the lid inlets in the barrels? this is connected to #3

3- what size PVC pipe should my flood lines be? does it matter? i have a bunch of 1" pvc but i see alot of large flood lines so im LOST

4- what size pump do I need for this system?

please someone answer i want to go buy parts today and start! thank you!

well my posts didnt get approved all day so i did a BAAAAAD thing, went shopping anyways lol
i went with 2" inlet in the front for flood lines. is that ok?

and 1" drains. if they are too small i can change them. i was going to fill the beds with perlite until i saw if you sneezed it will all blow away!

You have the basics you need for now - the GB's are your filter. A swirl filter (and a bio filter) can be added to the system - usually between the FT and the GB's - to provide extra filtration. This can be handy if you are stocking near maximum density of fish or if you want to do NFT/Floating Raft growing where particles and suspension factors are critical.Doesn't really matter, although having the water drop from a height might add DO (Dissolved Oxygen) into the system, it also wets the surface of the media and can cause algae growth. Not really a problem unless you get so much it is taking nutrients from your plants. I have mine entering the GB at the surface in the far corner from the outlet.

Do you have extra air for your FT? If you don't have enough DO your fish 'live on the edge' where any change to conditions can be critical. Plenty of DO in the FT gives greater resiliency.

These questions have a similar answer... it depends on how much water you need to put through the system. You have a 300g tank and the rule-or-thumb or basic level is turning the entire amount of water over in the FT at least once per hour. Allowing for head loss, you're probably looking at a 450g/hr pump.

I'd have a larger drain than inlet pipe. You are taking 4 drains (1 in each GB) and running them back to your FT - any back pressure and your drains slow and you might lose water over the edge of the GB's - maybe even pump your FT dry.

Have each GB standpipe drop into a larger pipe from the base of the GB's, but don't seal the join - in fact it is a good idea to leave a gap around the vertical pipe. Some people even put an elbow in and run the GB outlet a little way down the length of the large drain to ensure the drainage happens properly. If you did that you could also add a venturi to the GB outlet in the drain pipe to add O2 to the mix.

You could just use elbows to run each GB outlet back to the FT; personally I'd still run a single pipe drain instead - lets you move the GB's later on by simply adding drain pipe back to your tank. e.g. you might want to run a sump tank - ST's are good for keeping a constant height of water in your FT, something you are going to have to address with your system.

The way you have it now, you have 300g in your FT, and probably (guessing here) 150g shared in your GB's at any one time. On a F&D cycle, that 150g has to have somewhere to go - if your FT is already full you get to wash the floors, then when the pump kicks in you reduce your FT by 150g.

You may need to do some more reading - you state you don't want to do a siphon yet but will use flood and drain - siphons are the normal way to do that, unless you put a timer on your pump. Do some reading on Bell siphons and afnan siphons on site and also look at the constant flood (CF - aka constant flow) systems and see if that suits you.

Personally I prefer NOT to have my pump turning on and off constantly - most wear and failure points in machinery come during the start/stop cycles.

And if you put a standpipe in without a siphon you get water to the height of the standpipe just sitting in the bottom of your GB - it is likely you will then get anaerobic conditions in the bottom of the GB's - i.e. not a good thing.

If you're going to have a siphon later you should do it now - saves shovelling media later when you have to clear some out to put in a media guard and standpipe.

Cover your FT - any light getting in will make lovely algae conditions - although there are some fish that quite like algae as a food source.

Hi Rob , not sure what the wise will say but my system is of similar dimensions to yours and my plumbing is opposite in size to what you are suggesting . I have a 1 inch inlet and a 2 inch drain . Its been working flawlessly for 3 years now .

And don't use perlite as it will end up everywhere and be a nightmare. Use 3/4 inch gravel of some sort

so i got my plumbing narrowed down. 2" inlets and a 1600 GPH pump, it fills all 4 beds in exactly 5 min and shuts down, then drains slowly into the FT via the low holes in the standpipes. I scored the pump at Harbor Freight n Tool for $39 with a full 2 yr warranty

so far looks good, i avoided the perlite like the plague, i think ill maybe go clay ball medium or whtaever is affordable.

Hi Rob,

You'll probably get by with the Harbor Freight pump but it's overkill and makes it pretty tough and expensive if you were to try switching to Constant Flood (unless you get a different pump). The fish might not be to happy about the amount of water movement either.

As far as the pipe sizing - It depends on how you are planning to run your system. The delivery pipe to the growbeds is large on some systems because it is a gravity feed from the bottom of the fish tank, called a SLO (Solids Lifting Overflow). A normal scenario for this type of system would be what we call CHIFT PIST (Constant Height in Fish Tank Pump in Sump Tank) -

Pump in Sump ---> Fish Tank (drain via SLO) ---> Growbeds (Drain via standpipe) ----> Sump

Pipe from the pump would be maybe 1 or 2 inches for less resistance to flow. Pipe from the Fish tank would be 2 to 4 inches. The plumbing would split to the growbeds and the standpipe is usually one size larger than what goes in. Typically all the flows consolidate again on the way back to the sump (but they don't have to). I usually just figure pipe sizing based on the area for the inside of the pipes.

OK so you won't be running your system this way because you don't have a sump as far as I can tell but I thought I'd give you an idea of why you see the large pipes.

Your two inch pipe will be fine although the one inch pipe would have worked as well.

Regarding your pump - There is a lot of leeway but we normally shoot for pumping the volume of the fish tank once per hour. You have to take into account head height for the pump to determine how much it will pump. Basically that's how high above the water the outlet you're pumping to is. Most pumps have a chart that will tell you how much they will pump at a given head height.

Something else to think about is the cost to run the pump. It's frequently cheaper to get a better pump that uses less electricity and they often pay for themselves in a year or two by the savings. Check the watts on the pump, figure how much you're going to run the pump, then look at the cost per KWH on your electric bill to see what I mean.

Journeyman gave you a good answer. This was the only thing I didn't agree with, because there are workarounds and any issues you might see will be a long time coming (think years unless you overstock).

so is there a way to run this system so that my water level in the FT isn't dropping so far when i cycle it?

Yea, run it constant flood. Or put in a sump.

I'm very much a newbie, but I think the usual answers to this one are either:

1) run constant flood, that way the water level doesn't change (unless you get a power cut and it all drains into your fish tank?).

2) CHIFT PIST (Constant Height In Fish Tank, Pump In Sump Tank), basically you put in another (smaller?) sump tank with the pump in, the height then varies in the sump tank but stays constant for the fish. This requires q big change to the plumbing though.

3) Use a sequencing valve to fill each grow bed in turn. I don't know much about these, but if you have four grow beds, you'll drop the height variation to 1/4.

Maybe someone with more experience can advise which one would be better for your situation, if if there's another option I've missed.

Oh - another point, when you've filled your grow beds with media they won't hold as much water (perhaps a third?). So you'll get much less rastic height changes in the fish tank.

ok so how do i plumb a sump? my piping is made but not one piece is glued yet

i dont understand how to plumb it and how it empties the FT and doesn't lower it?

How many fish are you planning on putting in? If you're going to stock lightly then I don't think it's necessary to use a sump - just because with less fish they will have more space even with less water. I think if your FT is relatively full and you run it, then you won't see a huge drop in the water level - so I'm guessing it would be ok.

I know I'm new to this, but to me it seems unnecessary to add a sump. It looks like you already have everything you need for a good working system.

Can anyone verify this?

well thier concern is that i will empty the tank too fast and upset the fish. i plan to stock it decent, it will get stocked more as i add beds. i dont like the idea of dropping my FT drastically.

i think i am understanding wrong, i thought the goal was to quickly flood the beds (5-15 minutes) and have them drain slow, then repeat the next hr?

There are various methods that you can choose.

Those are 55 gallon drums right? (I work on the metric system so just making sure). But as mentioned earlier, once the GB's are full of media, you will only require about 1/3 of it's volume to fill it with water. So you have 2 barrels, that's 110 gallons/3 = 37 gallons. Obviously you won't be using the whole volume of the drum (it won't be filled with media all the way to the rim), so I'd guess that you'd need about 30 gallons to fill your GB's which is about 10% of your total volume (lets say 15% and assume you keep your FT decently full). So to me it doesn't seem to justify anything special.