Tardy discussion on tank size/depth in Texas.

[txdurk]

To TCL et al: Ioriginally messaged everyone due to my unfamiliarity with the web page interface. Won't be the last mistake I make I'm sure. Hope I did it correctly this time.

Originally I had asked about tank depth since I could only find 2' tall tanks locally. i am less concerned about this now but TCLynx tells me not to use galvanized tanks; I presume due to residue from the metal cladding process or rust but I'm guessing here. I am actually more concerned with blue poly not being food grade but, maybe, I'm all wet. Thoughts?

[TCLynx]

The 100 gallon tank extra deep beds do require 100 gallons of media to fill them but then you get the 100 gallon of filtration to go with it.  Now if all you are ever going to grow is little leaf lettuce and other small plants, the deep beds would be overkill and you might want more square footage of plants in order to use up the nutrients.

However, if you grow any greedy plants, the deep beds are great for big, top heavy or super size plants. 

So it is a balance between what you want with the system and where you prefer to spend the extra money.  For instance to get the same amount of filtration from the 50 gallon stock tanks, you need twice as many of them and you have to build stands to put them on so if you are going by sizing your filtration then the 100 gallon stock tanks are probably more cost effective.  If you are sizing based on how much square footage of planting space you want, then the choice between 50 gallon and 100 gallon stock tanks might be kinda close depending on how expensive appropriate gravel is in your location.

I personally always like to make sure there is plenty of filtration for the fish tank volume since so many people automatically want to stock the fish tank to the max and if the filtration isn't sized to handle it they often end up with a bad situation for the fish.  It really doesn't take that many fish to grow huge amounts of produce.

[txdurk]

TCL: what is your experience regarding how much water is drained from the 300 gallon FT in order to fill the 100 gallon GB?

[TCLynx]

I've been using the indexing valves so I'm not flooding all my beds at once.  But certainly you can flood one 100 gallon stock tank grow bed at a time from a 300 gallon fish tank with only a minimal water level fluctuation.  You could flood three of those 100 gallon stock tank beds at a time from a 300 gallon fish tank and still be ok.

With the indexing valve I run 6 of the 100 gallon stock tank beds with a 300 gallon fish tank and since I'm only flooding one bed at a time the water level fluctuation is minimal.

[txdurk]

TCL: My plan was to use an indexing valve so the question was around one 100 gallon GB at a time. It's good to know the FT water level is not affected that much. Thanks for the feedback.

Cheers.

[TCLynx]

Ya just gotta make sure your pump will be up to the job of driving an indexing valve.

The Gravity Modified version of the 1 1/4" valve I've used with the Quite one 4000 pump successfully as long as the head wasn't too high (like in ground tank feeding up to the 100 gallon stock tank grow beds works for my 300 gallon system.)

A Danner MD18 pump will drive whatever Aquaponics indexing valve you like.

[txdurk]

Thanks TCL.

[George]

That's the point of 100 gallon tanks - lots of media.

txdurk said:

I see you use the 100 gallon tanks for beds. I don't like them because of the amount of media required to fill them

[txdurk]

My thinking has matured a bit. If I did the math correctly, the 100 gallon tank with local stalite would cost me $600. Maybe that's affordable to some but it is a deal killer for an old vet living on disability. And I can feel the pain in my back already. Alternatively, our local tractor supply has "14" inch deep 45 gallon Rubbermaid tanks at $40; significantly cheaper. I can get roughly the equivalent of one 100 gallon tank of waste filtration with the benefit of more GB surface for $80 (2x$40)as opposed to $250 for one 100gal tank. I am now thinking six of the 45gal tanks with one locally sourced poly 6' round tank of 350 gal at a cost of $240. 350x .8= 280 real FT gallons. 280gal of FT vs ~240gal of Gb gives me a rough 1:1 ratio. The total cost without media is $480. What I'm saying is it's not always about what's best. Everything Is a compromise. I realize the discussion has not been around what's affordable but to me and I suspect many others, it's a prime consideration.

[TCLynx]

hay txdurk,

     So you are saying that tractor supply where you are is charging $250 for a 100 gallon rubbermaid, that sucks?  Dang around here the 50 gallon rubbermaid is like around $75 and the 100 gallon is about $80.  Is the 40 gallon really a rubbermaid?  Be ware if you get one of the other brands the material might not be sturdy enough to support media without bulging and you will need to reinforce it with some framing.  I applaud you for doing some research and careful thinking about what is most important to you and your system.  Be sure to expand that thinking to make sure you are not going for false economies.  For instance smaller beds but more of them will increase your need for plumbing fittings like the feed to the grow beds and the need for drains from the grow beds as well as the gravel guards and possibly the need for more framing and stuff to support the beds at your desired planting height and perhaps some reinforcement so make sure those added costs won't turn your savings upside down.  (IE "stepping over dollars to pick up pennies.")

And if it costs $500 to fill one 100 gallon rubbermaid with stalite there, then you should definitely look for other sources of rock since I believe TX has some locally produced expanded Shale (while Stalite is produced from slate in the Carolinas.)  I got about 200 gallons of stalite for about $100 but I did have to drive my truck to pick it up so the real cost was probably like $150 once we figure in mileage and gas and so on.

Also, on the topic of expanded slate or shale.  It is lighter yes, however it may also contain a large amount of fines or smaller bits that isn't necessarily desirable for your aquaponics system.  The amount of labor required to sift and then wash before placing it in the system might outweigh the benefit of it being lighter if you can get some really good appropriately sized river rock for a lot cheaper.  It may be very worth your while to get some sample buckets of the different stuff so you can run some tests and see how "dirty" it is before you buy a truck load.  Remember that you will probably only be washing the stuff once and if you set up a very ergonomic washing station it shouldn't be a back killer.  Especially if you get some youngster to fill the buckets or baskets from the pile on the ground and you can stand and swish in comfort.  Better yet, call it a workshop and have a bunch of people come over and help you wash the gravel, now a party is definitely the easy way to wash 300 gallons of gravel in a hurry.  Here is a blog post on the subect.

[txdurk]

Jimmeny Christmas, The 45gal is Rubbermaid priced at a 40gal but I totally screwed up the 100gal pricing. The 300gal is 250. The 100 is $70. That puts total cost of one 100gal tank with media at $224. I can never trust myself since I lost the right hemisphere of my brain last year. The Air Force is still trying to kill me it seems. So, sorry. It's my new reality. I understand the trade off with plumbing I think and a willing to accept that. With this new information however I must rethink this all for about the hundreth time. Framing would be cinder block which is very cheap. My main problem with or without cinder block is the area for my AP has about a 3-4" slope. Leveling tanks or blocks will take some time while leveling the entire area is totally impractical. As for river rock, it passed the vinegar test but I don't know the cost. It may be the better choice in the end. Stalite fines vs dirt on the river rock seems to be a "wash" to me either way.

[txdurk]

On a workshop, I don't think there is enough interest locally for it but being in Texas I can hire my choice of illegal Mexicans by the day or hour for heavy work (ignoring the right or wrong of doing that).

[TCLynx]

Well I don't know about your immediate local area in TX but I do know there are tons of people join up on this site from TX (granted it's a big place.)  But I got about a dozen people to come help me wash 300 gallons of gravel just by posting here and on garden web about it.  You just have to set up enough gravel washing stations, bins, baskets and buckets to keep several teams busy in order to get a lot of gravel washed in under 2 hours!

Biggest challenge is that if you are still figuring out what you are doing, it can be difficult to direct a whole crew of people about what to do or even know what you need set up in advance.  I do understand that difficulty in having a "party" to do the work.