File this one onder the "lessons learned" category!

My largest of 3 aquaponics systems was a roughly 700 gallon job that I built on the fly doing the "learn as you go" thing...

Originally, it was a floating raft system with four 30 gallon 2X3 foot by 8" deep mortar tubs as grow beds. I suspended the grow beds on a 2X4 frame resting on top of 4 concrete block pilings stacked 40" high. Since the wading pool fish tank was situated on a slight slope, I used shims on top of the block pilings to level the growbed frame.

Six weeks ago, I converted the floating rafts to gravel grow beds with pea gravel media. It was extremely heavy, but rock solid and level. The tomatos and cucumbers I planted in it literally exploded with growth. Some of the tomato vines were literally an inch in diameter and like 7 feet long! I had about 150 tilapia in it that had grown from 3/4" to 10 inches in length over a 7 month period. During the winter, I enclosed the system in a greenhouse tent - mainly to keep the water warm during our south Florida winter that occasionally saw temps as low as the high 30's - low 40's. Condensation in the greenhouse dripped down the sides and kept the soil surrounding the fish tank fairly moist.

A few days ago, I noticed overflow from some of my grow beds - a combination of bulging sides of the plastic mortar tubs and roots clogging the gravel screens in my auto-siphons had caused the problem. About 300 gallons had overflowed during the night before I discovered the problem and corrected it.

Yesterday, I removed the greenhouse. The ground surrounding the fish tank was extremely muddy from the condensation and previous overflow, but the system was running smoothly and all the grow bed leaks had been fixed.

This morning at 7:30 I was enjoying my morning coffee and watching the weather forecast when I heard a weird noise. It sounded suspiciously like somebody dumping a load of gravel into a puddle - which is exactly what it was!

I rushed outside to find that the entire growbed rack had dumped over onto the side of the fish tank - releasing about 650 of the 700 gallons in the system. Tilapia were flopping all over the back yard in puddles! Evidently the muddy soil had enabled one of the pilings to sink into the mud enough to shift the balance and dump the entire grow bed frame.

I enlisted my wife's help and we quickly grabbed thrashing tilapia and transported them with buckets to my 350 gallon system which is now HEAVILY overstocked! About 15 tilapia were goners and they went into a bucket of ice awaiting the filet knife for this afternoon's fish fry.

Looks like I'll be shoveling gravel out of the lawn for the next couple of days. The inflatable ring atop the Intrex pool is shot, but I was able to put several hundred gallons back into it so that I can relocate some of the tilapia temporarily while I enter re-build mode. My bio-filter will have to suffice to keep them alive until then.

I hated losing those beautiful cucumber and tomato plants, but what the hell - you gotta learn from your mistakes, right? At least I salvaged most of the tilapia. The new system will be relocated with the fish tank on more level ground with lined plywood growbeds suspended on a frame mounted on poured concrete (and carefully leveled) footers. I'll incorporate lessons learned into a much better and more carefully planned system. Live and learn!