Backyard Aquaponics
A place to discuss aquaponics

I use those square pond plant baskets with the media or gravel to swish in a couple bins of water before placing in the grow bed. This tends to sift out most of the fines as well as give a good initial rinse for the dust and it doesn't waste as much water as running water through the grow bed to waste. Probably uses less than 40 gallons of water to wash media for a 100 gallon grow bed. Water will still turn a bit cloudy but it will clear in a week or less usually depending on the dust and amount of bio-slime already in the system to help clear the water.

I don't bother with the distrobution grids personally.

Ok so i finally got my grow trays and my FT. Now i need to work on the pluming. It seems alot of people use 2 inch PVC for the systems. I am kinda using fayes system as a model. If she floods using the pipe going around the perimeter of the GBs, how does she drain her tables. I see she has overflows drains or is that a duel purpose drain.

ok, so did alittle snooping around. The stand pipe with holes drilled in seems to be the most common form of drain. Do you just drill little holes in the sides and leave the top open for over flow. I am guessing the small holes do not allow of enough water to be drained out while the table is flooding. by haveing the top open it acts as an over flow?

yes that is correct - don't drill holes in the sides - stick it in the standpipe connector and see where your holes will go right at the bottom - alternatively drill holes into the black bulkhead nut if you are using one.
Don't forget your gravel guard !!! which you haven't mentioned yet

The greenhouse finally arrived! I set it up today and have begun to layout my trays. Still working on the best arrangement.

The stand pipe with holes near the bottom is the most common drain type for TIMED flood and drain systems. You have to stop and start the flow to the grow bed usually using a timer to turn the pump on/off.

the other common way is to have the pump run constantly and you use an auto siphon of some sort to flood and drain the bed. Bell siphons are common for this.

The exact size of the plumbing will vary by purpose and size of the system and pump.
1" is a common stand pipe size. 2" for a drain that the stand pipe drains into to return the flow to a sump or fish tank at a distance from the bed or 3" for a combined drain that several beds drain into or for a really large system you might be looking at 4" or 6" pipe (but you won't be putting a really large system into your little greenhouse.)
As for the plumbing from the pump to the fish tank or grow beds (depending on system layout) you will base the minimum size of that plumbing on the size of the plumbing fitting from the pump but you can normally make that plumbing a bit bigger and get more flow from your pump than you would using the minimum size plumbing.

awsome thanks for the info. I am currently using 1.5" PVC for draining and 1" for flooding. I am making a diagram that i will have up soon. But as i ate some funky west african food last night i am stuck in bed.....