My Setup CRAFTS look like this below, it has five growbed with two return and a single feeder tank in the center.
After running this setup for few month I realize that the feeder tank is too small for five growbed operation. Four growbed is okay but with five water can be seriously low if not top up during this hot spell.
To ensure that system not compromise I had to reduce the number of growbed by one, so that water will be sufficient from that single 100 gallon Feeder Tank. In CRAFTS installation useable water volume is dependent on size of Feeder Tank, the bigger this tank the more water will be available and more growbed can be use. The Return Tank since it is constant level does not contribute to useable volume, it only allow more fish to be kept in a setup.
Removing one growbed will reduce the amount of plants that I can grow and also reduce the biofilteration of my setup. I decide to make one growbed into Continuous Flow growbed. Continuous Flow is actually DWC with a media filled growbed. This approach, since water is always same level in this growbed it will not be counted as water that being use from the Feeder Tank but as part of the Feeder Tank itself.
All plants removed from center growbed, I need to replace the standpipe with the one without a leak hole. All pebbles has to be removed too.
Once converted to continuous flood, not all plants can tolerate their roots submerge in water. So some of these plants above may not survive some will.
Old siphon removed, will install siphon without a leak hole. Continuous flood just requires the bell removed to do the overflow.
Strainer holder and stand pipe in, next to put strainer and all the pebbles back in.
Done, these two are the only parts affected. The tank fitting replace with no leak hole (above photo the one with leak hole) and siphon bell not needed. However occasionally it's best to place the bell in to do few flush so that we get good water flushing preventing anaerobic buildup.
Water level shown from top.
Completed growbed above, will start planting next. Water always at top of stand pipe in this growbed and it will not take up water volume from Feeder Tank but act as reservoir.
Great now I can try continuous flood growbed.