Backyard Aquaponics
A place to discuss aquaponics

I've seen a lot of common mistakes happen repeatedly and some not so common ones that are pretty tragic that I thought a thread about such things might help new people avoid some of them.

Here is one of the common ones.
Media choice, using limestone gravel. (Marble is also limestone so avoid it too) Limestone gravel causes pH to remain too high for most plants to grow well. Not really possible to correct by adding acid either since it would take until all the limestone dissolved to get rid of the overly high buffer.

Another less common but rather tragic mistake I've seen a few pictures of is, not enough support for grow beds
Luckily the pictures I've seen were of beds that collapsed or fell over but no people were injured in those. I do dread that some one will fill a container with gravel and some one will get hurt in the collapse. Please over engineer the stands for your grow beds.

My lately discovered mistake was using old posts and untreated wood for my lumber and liner grow beds in a termite prone area. The termites came up through the old nasty posts into the untreated wood and ate right into the liner which caused a leak.

Not bothering to secure plumbing from the pump to the grow beds I've read some threads where people have simply placed the flexible tubing from a pump up to the grow bed without any way to keep it from being bumped off the grow bed. This can result in the hose falling out of the grow bed and when the pump emptying the fish tank. Please secure the tubing. This can often be as simple as a screw and string tied around the tubing to keep it in place if bumped.

Gravel filled pipes This is somewhat contested because some people manage to do it on a small scale but for the most part, pipes filled with gravel to grow plants in, tend to clog up with solids and roots and then have issues with overflowing.

Pumping fish tank water directly to NFT pipes and having no filtration. This one is a multiple problem. First the fish won't do well because there is no filtration for them and could easily result in complete fish kills. Then the plants may suffer for two reasons, 1 the solids from the fish tank can build up around the roots and cause poor aeration or even root rot. 2 the complete lack of filtration can leave the plants starving for nutrients since the plants use nitrates and bio-filtration is needed to convert ammonia to nitrite and nitrite to the nitrates that plants need.

Expecting water to flow up Don't expect a drain to work if the outlet is higher than the inlet. Conserve your fall when designing a system and realize that the water level in a CHIFT PIST fish tank needs to be a bit higher than the top of the grow beds it is to feed and that the sump tank must be below the bottom of the grow beds draining into it.

And the number one mistake I've seen most......... Pipes too small! I've experienced this mistake myself. I thought the pump was too whimpy for the job but the truth was actually that I was making it pump through too small of pipes which restricted it and solids would build up even more as the flow slowed even more till noting was being pumped. When I later hooked that same pump to way over sized pipes it worked fine. The original plumbing I had hooked to it was nominally the same size as the pump outlet so I figured it would be appropriate but I was wrong and the fittings for irrigation pipe tend to restrict the flow even more so it didn't work. Anyway, bigger is generally better for plumbing in an AP system and this is especially true for gravity drains.

I just realized I've started a similar thread over in Basic Info. I'll post the link here but I see that in this thread, I've mentioned some of the more tragic mistakes than I did in the other thread.

http://backyardaquaponics.com/forum/viewtopic.php?f=12&t=5757&hilit=basic