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REEFBUG
04-27-2010, 10:46 AM
Hi Guys, been making sketches and doing lots of plumbing in my head and it has created a couple of questions. First a quick explanation of my design. Thinking CHIFT-PIST design, FT will gravity feed to F & D beds, bell siphon into sump, pump back into FT. Here are the questions: How do I deal with solids? As the overflow from FT to beds will have to be near the top of FT, would it be a good idea to just have a valve at the bottom of the FT and drain a few seconds into a bucket every few (days) and just manually dump into beds?

The grow beds in a F & D design act as the biological filter, but when they dry out does the bacteria not die? Are they not really that dry for very long? I live in Tucson, 100+ degrees for 100 days in the summer.

GB volume vs FT volume, I have seen some discussion of this but nothing definitive, for a 150 gallon FT that means up to 450 gallon GB, is that total volume of GB (medium + water) or just water volume? Just water volume doesn't seem practical.

Are galvanized troughs OK for a GB or FT? I would think not, because it has Zinc in the coating. Is painting OK and with what paint?

Thanks for all the help!

Chris

badflash
04-27-2010, 02:32 PM
The solids go into the grow beds. Put in some red worms and they will help break it down so the plants can absorb it. If you have the cycle time correct, the beds will not dry out.

I posted a thread on how to size your biological filter.
Calculating your Bio-filter (http://www.diyaquaponics.com/forum/showthread.php?128-Calculating-your-Bio-filter)
It is actually tiny compared to the fish volume to convert the ammonia and nitrites. The bigger issue is nitrate buildup. This is a function of how fast your plants take up nutrients. This means you need surface area and not volume. If you harvest all your plants at once, it doesn't matter how large your grow bed is. A good rule of thumb is that the bed volume should be 3 times the fish volume, and the surface area of the grow bed needs to be large enough to support the plants needed to keep the balance. The bed volume includes the growing media.

REEFBUG
04-27-2010, 03:09 PM
Thanks for the info Badflash, but I still have a question about getting the solids to the beds, the overflow from the FT to the GB will need to be mounted high on the FT to prevent it from draining in the event of pump failure, right? That leads to how are the solids getting to the GB if the water is coming off the top and the solids are on the bottom of the FT?

Thanks!

davidstcldfl
04-27-2010, 03:24 PM
Hi Reefbug.


Here are the questions: How do I deal with solids? As the overflow from FT to beds will have to be near the top of FT,
If you build a slo-drain, it will help get the solids off the bottom. Check out the drawing....hope it helps.
Go a little bigger on the size of pipe for your FT drain, then you think you may need. This is one time 'bigger is better'. You can cut slots in the lower section of the slo-drain.....I used a cut off saw......or drill holes in it.
Your water level will be about where the tee is on the slo drain.
The pipe above the water level, needs to be 'open', otherwise you'll have a siphon, instaed of a drain.

I just noticed, I drew the drain on the GB incorrectly...If your doing a bell siphon, the drain will be comming out the bottom.

http://i931.photobucket.com/albums/ad157/davidstcldfl/CHIFTPIST.jpg


Are galvanized troughs OK for a GB or FT? I would think not, because it has Zinc in the coating. Is painting OK and with what paint?

Your correct about the zinc. You could line them with rubber pond liner.
I would think you would want to use an epoxy paint....some thing like this.....
http://www.aquaticeco.com/subcategories ... %20paint/0 (http://www.aquaticeco.com/subcategories/3048/Sweetwater-Epoxy-Paints-1-Gallon/epoxy%20paint/0)

You want to have deep grow beds, especially with your heat. More voulume will take longer to heat up. I even put some shade cloth over the GB's themselves to help cut down on the sun/heat.

REEFBUG
04-27-2010, 03:28 PM
Thanks David! That picture helped a lot! Makes sense now.

Chris

badflash
04-27-2010, 07:20 PM
Suction of the pump should be at the low point for the solids. The beds should be above the fish. That is all the more complicated it is.

REEFBUG
04-27-2010, 09:41 PM
Badflash, I was thinking of that design also, pumping from the FT to the GB then gravity puts the water back, doesn't that leave the potential for the water level to vary quite a bit in the FT?

wolfracer
04-30-2010, 07:13 AM
CHIFT-PIST is the design I use ( see Wolfracers system) . I maintain the level of the fish tank by a 1-1/2" overflow to the sump. My feed line to the grow beds runs clear to the bottom of the fish tank and is 1-1/2" I also have a tee with a pipe running above the tank to prevent the feed line from siphoning out the tank. Gravity feed to the growbeds, believe me I pull plenty of solids off off the bottom.

This has worked well until my fish got to the size they are now. I have also sort of crashed my system by pulling out plants and replanting with herbs and it is now recovering. Nitrates never got really high and the nitrites were still 0 but I do have lots of solids and murky water. Good thing catfish are tough. I am adding a swirl filter to the system today and will post pictures.

jackalope
04-30-2010, 08:30 AM
CHIFT-PIST is the design I use ( see Wolfracers system) . I maintain the level of the fish tank by a 1-1/2" overflow to the sump. My feed line to the grow beds runs clear to the bottom of the fish tank and is 1-1/2" I also have a tee with a pipe running above the tank to prevent the feed line from siphoning out the tank. Gravity feed to the growbeds, believe me I pull plenty of solids off off the bottom.

This has worked well until my fish got to the size they are now. I have also sort of crashed my system by pulling out plants and replanting with herbs and it is now recovering. Nitrates never got really high and the nitrites were still 0 but I do have lots of solids and murky water. Good thing catfish are tough. I am adding a swirl filter to the system today and will post pictures.

My problem with putting the solids into the GB is that they tend to go septic if any water is left in the GB .... My plan is to suck the solids off the bottom into a 'swirly', then into a GB/biofilter, and then back to the biofilter. (can't do that now, of course, it's snowing outside again :(). right now, with the way things are laid out, I'm trying to decide whether or not I will have to put in another pump or build a stand so it can be gravity-fed. [b]REEFBUG,[b] it sounds like you've really thought this thru, keep it up and you'll have your system up and running before you know it! :mrgreen: :mrgreen:

badflash
04-30-2010, 02:37 PM
In a properly sized system the bio activity in the grow beds will break down the solids. Red worms will help a lot. Just be sure to set up your system so the beds will properly dtain and allow air in. Most plant do better that way. Some won't survive at all if you don't.


Yes the water level can change a bit in the fish tank, but that doesn't hurt a thing.