Backyard Aquaponics
A place to discuss aquaponics

I want to set up my system with a (near) full (55Gal)BBL fish tank
& 4 1/2 BBL grow tanks. I am trying to decide on Flood & Drain or
Constant Flow. Suggestions anyone ???
I assume a 1/2 BBL filled to @ 2" of top with gravel might contain
15 Gal of water. What does your experience tell you on this water
Qty??? That leads me to believe that I will need @ 60 Gal + @ 40 Gal
for fish if I use constant flow. The flow(drainback) would then be
controled to match the pump capacity. Am I on the right track?
I would like to use a 12V pump either @9 GPM flow constant
(Automotive){$175}. or @4.9 GPM intermittent (Sprayer){$95.}Either
way I will have to buy a battery(s) & a Solar panel controller to
make this work.9GPM=11.1 minutes for full pumping of 100 Gal.. 4.9
GPM=20 mins. for 100 gal. Perhaps I should look to pump the Growbed
capacity of 60 Gal in @ 12 mins. Can someone please give me your
experience on this! I have 2 75W Solar Panels & would not need to
run new wiring for a 120V pump.

I had a formula of how many fish to a Gallon of Fish tank vs
gallons of Growbeds. Can you help with this as I can no longer find
that info???????? I have a source for 100 1-2" Talapia for $50. if
it is still a good source. Since I think that is too many as they
grow, perhaps I can offer them as fingerlings when they out grow the
fishtank. How many fish should I start with????

Any other suggestions????????????????? How about starting the
bacteria in the grow beds? I plan to use gravel,I have lefttover from
the driveway & later try something used to expand concrete. It must
look like Lava rock and is supposedly very light weight. Has anyone
tried this stuff.

Thanks for any help with this project. I've retired & look forward
to finally trying my hand at this. EdH

We caught another one!!!!!!!!

First bit of advice, read and lurk a bit as you start tinkering. There is tons of info here and it will take some time to digest. I know many of the threads seem way too long to get through but you should probably pick a few of the long Member System Threads for a through read so you can get an idea of how things go. (Take heart, some of those really long threads have lots of pages that are really quick to go through as there is much congrats when things are good and condolences when things go bad. Other threads just seem really long as they are full of pictures and therefore very quick to read!)


My vote is for flood and drain but with a constant flowing pump using siphons to drain. There are endless ways you can design your system but if you want some structure your first time out, I will suggest that the barrel ponics manual is very helpful for construction of a simple system that can run on a very small flow pump. (my first system is a barrel ponics set up)
A small constant flowing pump would probably be easier to do with the 12V solar stuff than trying to run a bigger pump with timers and all that sort of stuff. I don't like trying to do constant flow drip sort of stuff as they require constant cleaning or leave most of your gravel dry.

The estimate of 40% of the volume of a grow bed is a generally accepted number for the amount of water it will hold once filled with gravel. So, 55 divide by 2 is about 27.5 but since you are not filling to the top, call it 25 (it is probably even less than that.) 40% of 25 is 10.
so each barrel half full of gravel will probably require about 10 gallons to flood (remember that we usually only want to flood to about an inch below the top of the gravel.)
If you are flooding all 4 barrel halves from the one fish tank with one pump (assuming you are not cascading anything) and have no sump (or header, or flush tank, Your poor fish will be flopping around in about 10 gallons or less of water. This is why most systems that start approaching the 2:1 gravel to tank ratio, wind up using some sort of sump or other method to help maintain fish tank water level.

That 2:1 ration of grow bed to fish tank is only if you are approaching the max capacity of tank to fish amount. I do no really know the appropriate amount of fish per gallon of tank and this greatly varies depending on the local conditions, maturity of system, your ability to care for the fish etc..... The truly important factor is the amount of fish to the grow bed capacity to handle the waste of those fish. This truly important factor is actually a very fine balancing act that becomes easier as a system matures (of course this is me only repeating what I have read from others as I have only had fish for about a month.) If you plan you system carefully, you may be able to add capacity as you learn and decide if you like this obsession. I started my big system with one big in ground tank and two large grow beds. I have since added two more large grow beds, one smaller bed, another 300 gallons of tank, and have plans for a (really big) 600 gallon grow bed which will require the addition of a sump pump.

How many fish, hum. Many people just start with a few goldfish while they learn. I started with 50 catfish in 600 gallons but that was after fishless cycling on hummonia.

Getting bacteria started in the gravel, now that is something I'm good at!!!!! Look into fishless cycling, this can be done with pure ammonia (make sure there are no detergent additives or anything else in it if you go this way.) Some people also use urea but I definitely think using one's own pee is the way to go (it doesn't require much.)
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=2534&st=0&sk=t&sd=a

As to the other types of media, test some out. If you can get a bit of it and soak in some water to monitor what it does to pH, that can be important. With any concrete, just take into account what you may or may not know about the chemicals or additives they might have use in it. It is up to you to figure out what you feel safe using.

Before you get too far along, you will want to get yourself some aquarium testing supplies. Most people here think test strips are not accurate. I tend to agree.
Get the kits with test tubes and drops. The types of tests you need include;
pH (they often come in regular and high range, the master kit comes with both)
Ammonia
Nitrite
Nitrate
If you search online, you should be able to find the Aquarium Pharmaceuticals Freshwater master test kit for less than $20 plus shipping. You can probably also find this kit at a local pet shop but it will likely cost over $35 there plus sales tax and drive time.

Good luck and keep posting!!!!!!

WOW TCLynx, Great info there ,, you better start charging by the hour LOL

Naw, info is free on a forum. If I have the time (like this week with no work) I will happily regurgitate what I have learning on the forum and tinking on my own for anyone asking.

Now when things get busy for me, I will vanish for weeks on end.

Then again, if some one wanted me to come to their place and set up a system for them (and then of course maintain it for them as I believe most people who don't do the initial tinkering themselves, probably won't have the connection to it to maintain it. *I know we have an exception to this on our forum*) It would cost them a pretty penny as I'm used to being paid well when I do work.

I believe forums should always be free and info freely given on them. When I see people posting on a forum, hinting that they could share more info but not freely, I think, then why come here. Granted, since all the info is free and some gets jumbled and the advice is only as good as the people's ability to explain things in type from descriptions explained by others, everyone has to judge for themselves what is best to do, still, that is what forums are for!!!!

OOPS ,, my comment regarding charging for advice was in NO way suggesting anyone here should charge. It's Aussie humour ..... a lot of others find it crazy.

I'm happy to share my knowledge for free ,, want to know some words in Vietnamese , I'm the man ,, want to know about Tilapia in ponds , I'm the man ,, want to know how to get 7 Thai gals in a spa ,, I'm the man ,, want to know how to have the worlds most horrible divorce I'm the man ..BY THE way the last two things written happened in reverse cronological order.

Free interchange of ideas and then proven result /reality , is what we want here. Well I should not speak for others ,, that is what I want here.

Smiles all round.

I do know you were joking Chappo, no worries there

pfatz, how's the system planning going

Whoa, somehow, I just blew 15 mins typing a reply.Somehow it just went away.

TCLynx Thanks for all the info. I read & printed it. I am making a sketch and parts list tho I still have questions.

Let me try to layout a system & see what questions come up. I think I need a 100 Gal. Fish tank after reading your post. It just makes good sense. OK; 100 Gal Fish Tank> pump pickup line> Pump 3.5 to 5GPM(Solar power @ 12V) >manifold pipe for 4 Growbeds(3/8 crushed stone washed)>(here I see 2 posibillities, A single pipe into each GB or a sprinkler pipe of sorts to each GB)Flow at this point is full pump volume( some type of constriction or valve would control volume if needed)>thru tank>drainback line to manifold & return direct to tank(with or w/o valve or constriction to match drainback to pump input). Have I just described a simple Constant Flow system? A timer might control this or is there a better way? Timed fill & controlled drainback would make it an Flood & Ebb. Darn, it sound so simple. Maybe I am on the right track.

OK, take it apart & tell me where I might go astray? A pump such as used in an RV system can run dry & switches on & off controlled by demand (IE: back pressure) I am not controlling pump input unless I use a timer? A lesser volume pump costs less $$$$. How much pump volume do I really need?

It sound like a Timer may be the way to go with valves or constrictions on drainback only to cause tanks to fill.pump to shutoff and drainback controlled for time desired before refill.

What do you think of all that. Next question is: How do I clean out the Fishtank& how often would it need to be done?

I think to start up a system>adjustments> work on bacteria & testing>put in fish(or plants first???)that was a chicken or egg ??, introduce plants or fish per instructions>complete system! That brings up a question of Aeration?? If drainback is above the water surface @ 12" or more, will it provide sufficient aeration(intrduction of oxygen) by my understanding?

I think this is book length transfer of info. Thanks for your help! EdH

I think You are on the right track, here are some comments about your different options.

My systems use a simple pipe (usually with a ball valve) into each grow bed. I don't like the spray bar method as you have to unclog it cause fish waste gets in there (and we want fish waste to get into the grow beds, it is a good thing.)

There are two primary methods for flood and drain, timers or auto siphons.

With timers you can do things a couple of ways. You can plumb the pump into the bottoms of the beds so when the timer shuts off the water simply flows back through the pump into the fish tank (this only works with some types of pumps.) Another timer option is to have a slow drain (you also need a fast enough overflow/high water drain in case the main drain gets
clogged or the pump keep running too long due to timer failure) where the pump fills the beds faster than the drain flows and then the pump shuts off for a time allowing the bed to drain.

If it is easier for you to have the pump run all the time (like if a timer for the 12V system is difficult to come by) you can have a slow pump run all the time but effectively automate the drains with auto siphons. The trickiest part of auto siphons is that you need to balance the inflow with the outflow of the siphon. If the inflow is too slow, the bed will fill to a point and then trickle out but never really start the siphon enough to drain the bed again. If the inflow is too fast the siphon will kick in but then keep sucking water out keeping the bed mostly drained. The happy medium is where the bed fills and drains regularly with the pump running constantly. There are a few types of auto siphons an each has pros and cons. some people hate them and others love them. I've had my best luck with loop siphons but Ell seems to be a guru of bell siphons. I also have a Flout running in one of my grow beds and it is great but it would take up too much space in a blue barrel I think.

I don't know much about the pumps you are talking about. You probably don't want to let them run dry as that would probably mean your fish are out of water! You want pumps that are safe for your fish (can't leak oil into the water.) And you want them to be able to handle some salt in the water without corroding and ruining them. How much volume you need depends on how you decide to set up the system (auto siphons require you to do some flow balancing). Extra volume is generally not a problem because it can be used to aerate the fish water extra. I do encourage you to check out the Barrel Ponics Manual (you can download it free! http://backyardaquaponics.com/pics/barrel-ponics.pdf With some of those methods, you could effectively flood and drain with some very slow pumping rates. He uses a flush valve like for a toilet in a flush tank but I suppose you could look up Flouts and adapt the idea for that too. It does require an extra barrel though.


You want your pump to suck up much of the gunk that builds up in the fish tank so you don't need to really clean it to often. That is the beauty of Aquaponics as compared to keeping an aquarium. The gravel beds are your filters and water cleaners and the plants are to suck up the extra nitrates so you don't have to do water changes. (of course that is so long as all things are functioning properly and balanced.)



1-Get things set up and test out plumbing first!!!! Tinker with the plumbing/timers/etc. If you need to fix plumbing, you don't want the beds already full of gravel!!! Just remember that the time it takes to fill/drain the beds and the amount of water needed for such will change greatly once you add gravel.

2-Wash gravel & fill beds, then test filling and draining.

3-Let the system run and get the bacteria started (if you peed in a bottle a while back, it may be aged long enough to add to the system, you only need about 250 ml to get started.)
As the system runs, the water should slowly clear. Perhaps an old sock to catch particles will help but once you have some bio-slime going, water will clear quickly. Now is the time to practice with your test kit. See how high the Ammonia spikes after mixing some into the system and then see how long it take the ammonia to get to 0. Watch for the Nitrite spike. .... and so on.

4-If you have done step 3 as fishless cycling, you can start your plants right away. Otherwise, you will be cycling with fish (much more nerve racking) and you can probably still start your plants about the same time you add fish. I actually had lots of plants started when I got my fish. I just kept them going by adding humonia until I got my fish.

When you start seeds, you really don't need nutrients. It is only when the first true leaves start to come out that the plant is really ready for much in the way of nutrients though seeds seem quite able to start in an AP system either way. If there aren't enough nutrients for the plants, most of them will survive for a time but you won't see much growth.

Solar powered pump ,, hope you've got back-up ,, remember clouds , night etc.

I imagine you have battery back-up , Has anyone calculated the environmental cost of these solar panels , batteries ( and disposal of same)and the inefficient use of DC powered pumps Vs just plugging into" green" power mains?

As for sizing of tanks etc ,, i recommend you asess how much fish your family requires.
My family consumes approximately 4 kilograms of fish per week . So I be;ieve i should aim at 4 kilo per week production.Not many people would want to eat the same type of fish day in and day out ,, so at least two species should be contemplated.
Each species will have different growth rates at different temperatures ,, so you need to balance these in order to achieve what your home requirement of fish actually is.

Simple it is not ,, calculable i believe it is , variable depending on environmental situation I am sure it is.

I'd love to calculate for you ,, but FARK I'm spending weeks working out the best just for my own back-yard.
Cheers and best of luck, best advice I can give is READ , here , LISTEN here ,, there is a wealth of information ,, filter that info so it suits your situation and all will be good.

Bloody kangaroo is knocking on the back door ,, knows it's time for me to go to work,, must saddle him up and get going.

TCL... I'm going to follow Steve's lead..... you have learnt well grasshopper....

And have a great way of summarising and passing on that knowledge....

Thanks All, I picked up a poly tank yesterday....110 Gls & made a deal for another one at same price (cheaper by 2's) , which is going up daily. I think I might couple the two and grow Duckweed in one and use it as a buffer to allow pumping more water if I want to expand or to create a hatchery or starter tank for fry. Anyway, got both tanks for $108.. It'll come in handy I know. I also got a 5GPM 12V Pump. I'm searching for a timer(simple on-off). A side note. I looked at a magnetic drive pump (12)V, made for computer cooling. It has a 50,000 Hours MTBF. It has onboard volume control allowing adjustment of 1,2,3,4,5 GPM, @ $90. I may order 1 to allow me to experiment a bit and as a backup. It would drop right in to replace the pump I now plan on using & have on hand. I live in the boonies & everyone is looking for the frre stuff, so I resort to spending the money Prez Bush is so kindly sending out. Feeding my family is a good use for it anyway.

I am preparing a catch barrel for rain water but the (normal) dry season is about to start. If necessary, I will have to resort to tap water. Should I treat it or something to compensate for the junk in it???

If I join the two tanks, I will need to place a screen to prevent fry from moving to the Duckweed tank, right. Supposing I find fry to start out with. I am considering adding a filter that screws into the pump (which is a diaphram pump by the way) to filter out any unwanted solid stuff. Would I need such a filter??

I appreciate your comments. Very helpful for me & probably other newbies.

Thanks again EdH

You want to be able to pump fish poo up to the grow beds so a prefilter on the pump will only get clogged up requiring you to clean it all the time. Just make sure your little pump can handle pumping soft solids.

Having a backup pump is a good thing.

Contact the water company and ask them what kind of chemical treatment they use on your water. You can probably also get a copy of the latest water report showing the conditions of the water at the time it was last tested. If the water is treated with chlorine, then there are several ways you can handle it (including, putting it in a container with a bubbler and letting it off gass the chlorine.) If it is treated with something else like chloramine, you may need to filter it with a filter that takes care of chloramime, some other purifier methods might work too or they make water conditioners/agers (look in aquarium shops) that can take care of it too but read the lables carefully before using them.

Do you have (or have you ordered) a test kit yet? You will want to test your source water for pH, Ammonia, and Nitrate just so you know and before you get fish or start cycling, you want to have a Nitrite test kit on hand as well.

TCLynx
Thanks, I will talk to the water dept. I think they use chlorine.

I have searched for test kits and will order the appropriate ones in the next day or so.

I am also searching for Talapia suppliers. I saw a list of Hatcheries & Equipment suppliers for all over the country but naturally, I can no longer find it. It listed several in Oklahoma & Arkansas which might have worked well for me.

I am not ready for fish yet of course but I want to have all my sourses worked out by the time I have the dry setup and add water for testing & adjustment. I am sure I will want to move on quickly when I reach that point.

Thanks again. EdH

No need to rush too quickly even once things are running wet!!!! Then you can fishless cycle and even get plants started before you need fish. Just remember that if you fishless cycle or even cycle with throw away goldfish, you will need to keep giving the system something to keep your bacteria alive and ready for fish when you get them. (this could be as simple as feeding the system some fish food, ammonia without any additives, aged human urine in small amounts, or perhaps some other fish safe fertilizer source.)

Good luck and have fun.

yes pre filters and even those sponges in the pumps are a bad idea, remove them.

you now how i clean my FT? i add 45 trout

seriously, there was a lot of accumulated sediment in my 1000L tank, only a few fish.

since the 45 trout went in the bottom is actually WHITE again! incredible how much water movement 45 fish can make