Beginners

[Peggy Worthington]

First Post....first time posting anywhere, so bare with me, please.  My husband and I are starting an aquaponics system after researching and reading a lot of info over past two weeks.  We now have a 300 gallon fish tank and 3- 50 gallon grow beds (11inches high)  We have made the bell siphons for the grow beds and made sure they are working properly.  We are working on the rest of the plumbing while waiting for the pump to arrive.  The problem at this point is grow media.  Can anyone suggest where to buy a suitable (cheap is better) media in northwest Florida.  Would concrete places have something suitable?  My husband figures we need around 24 cubic feet.  Thanks

[TCLynx]

You might contact Conrad Yelvington and find out the price on 1/2" or 3/4" brown river rock in your area.  You would need a big truck or dump trailer to get it though.

Here in FL I would say avoid pea gravel, it will probably be limestone.

If you want something lighter weight, contact me, I sent you a friend request so you should be able to accept it and send me a message.  I may be able to find you some options in FL.

[Leo White Bear]

Peggy-

  I would be very leary about acquiring you media from a concrete manufacturing facility as concrete contains lime and gypsum both will play havoc with your pH, you will not be happy.  I would search out landscaping businesses and see if you can acquire some granet.  A bit of advice, when going out to your decided media supplyer, bring along some white vinegar.  and a vessel to put your selection into.  Pour the vinegar over the4 media, if it foams or bubbles even just a little, decide on something else.  This agragate contains limestone which will raise the pH in your system (even certian types of granet contains limestone so be very selective). 

  I am fourtunate enough to be able to acquire what is called "Pink Lady" which is a pH neutral agragate and is very inexpensive per cubic yard  $24.00 as compares to pea gravel @ $36.00 per cubic yard.  I hope this helps you out.

White Bear

[TCLynx]

Unfortunately gravel is rather more expensive here in FL since most of it has to be transported in via truck or rail.  Limestone and shells are what most of the state might mine locally, otherwise it all comes from elsewhere.

Pea gravel is generally whatever the local 3/8-1/2" gravel is.  Pea gravel only kinda describes shape/size, does not tell you what kind of rock it is.

Aggregate suppliers can be a fine place to get gravel but they are not necessarily easy for some one not in the construction, concrete or road industry to deal with.  They are not a public showroom and it may be hit or miss as to getting some one to talk to who can understand what you are asking.  They are generally also not interested in delivering small amounts, first time I called one of them they did understand when I said I needed a non-limestone aggregate but they didn't deal in orders of less than 20 tons.  I didn't ask the right questions though, their trucks don't deal in small orders but if you can arrange your own delivery vehicle, they will sell smaller orders (probably not worth it for less than 1/2 a ton though.)  There are plenty of dump trailer or small dump truck drivers you could probably hire to haul a load up up to 6 tons.

Then of course you need to convert the ton into a volume weight you can understand.  Ask if they know how many tons it takes to make a cubic yard.  The 1/2" brown river rock I use takes 1.25 ton to fill a cubic yard.  The expanded Slate I've been using takes 1 ton to fill 1.33 cubic yards.

Beware the fiz test with vinegar will be misleading on most expanded slate or expanded shale since most of them have dust on them that will fiz when first introduced to acid, that needs to be rinsed off or neutralized with acid before the Fizz test will be useful.  Take note, limestone will just keep on fizzing till it is pretty much all dissolved away, I don't care how many times you drop it in a new glass of vinegar.

[Leo White Bear]

I still say check out some landscaping companies, they are in the business of selling small quantities of rock.  Since Florida has to have most if not all their aggrigate shipped in you might want to go with the more expensive Hydroton, clay balls, or scoria, lava rock, and bypass all the hassel.  As for me, like I said I can get granet that is pH neutral, but you don't live in Wisconsin.

White Bear

[TCLynx]

Yea, if you can find a landscape aggregate supplier that will deliver for a reasonable price in your area, go for it.

However, I've still never been able to bring myself to pay for the Hydroton, even with rocks being more expensive here, Hydroton is still more expensive.  I can fill 12 beds with gravel for the price it would take to fill 1 bed with hydroton.

Expanded shale or expanded slate might be a more viable option if you want something lighter than brown river rock.  Lava rock would be ok if you can find it in the appropriate size range but it is much harder to dig in and really needs lots of washing before use.

[Nicolas]

Hi, im a beginner too..
I just got my grow media (lava rocks) at a landscaping store

also, my other comment for you (and keep in mind that im a beginner) but i think that you're going to need 3 more of those 50 gallon garden beds so you have at least the 1 to 1 ratio (garden beds, fish tanks)

[TCLynx]

Nicolas,

    Welcome.  Yes having a 1 to 1 ratio between media grow beds and fish tank is generally a good idea.  However, as long as one is not tempted to stock to many fish, you don't HAVE to HAVE the 1 to 1 ratio.  For a beginner, this means you should only stock about 1 fish per 7.5 gallons of media bed or 1 fish per cubic foot of media bed.  And start out with small fish!

I had some one come to visit the other day that thought they were going to raise 300-500 fish in an IBC with just the IBC's top as a grow bed!?!?!?!?!?!?   NOOOOOOOOO   if the IBC top is 1 foot deep, I would tell people to start out with 12 fingerlings that might grow out to up to a pound.

Anyway, the original posters 150 gallons of grow beds would be suitable to about 20 fish for the first season.  (maybe only 10 if growing channel catfish.)  Once more experienced then I might say you could grow more bluegill in such a system since you don't grow them as big.  If adding 3 more beds for a total of 300 gallons of gravel bed then starting out with 40 fish would be ok but remember that more flood and drain beds means more water level fluctuation in the fish tank so you can't push the socking density of the fish up much more without doing something to deal with water level fluctuation (like a sump tank or indexing valve (sequencing the flood and drain of the beds.)