Cleaning New Gravel and Pipe Size

Cleaning Gravel:

Yesterday I cleaned about 5 cubic feet of new gravel.  In the past I have used progressive tubs and a bucket filled with holes.  I would start at one end and work my way down three or four barrels of progressively cleaner water.  This proved to be insufficient and the barrels became quite dirty very quickly which meant that I would constantly have to start over with more clean water.

But yesterday I used a small cement mixer.  Id put 10 shovel fulls of gravel in and filled it with water.  Then turn the mixer on for 15 seconds, and dump the water.  I did do this about 7 or 8 times until the water was running clear.

This next step may not be necessary, but then I did a final rinse in a white bucket.  I was able to easily see how clean the water was in the white bucket, and two quick rinses generally finished the job.

It took a few hours to perform this cleaning, but after several bad experiences with cloudy water, Im very happy with the results.  Today my water is perfectly clear.  

Pipe Size:

A couple months ago I added 10 feet of 1-1/4" pipe to the line from my fish tank to the grow bed.  It has worked well until recently when I noticed that the water in the fish tank was beginning to raise.  Closer inspection of the pipe revealed that gunk had built up on the surface and was slowing the water down.   I replaced the pipe with a clean 2" pipe.   Ill let you know in a few months how that worked out.   Im feeling confident that this is going to work out much better.    As a general rule Id say 2" or larger pipe should be used everywhere.

Read More..

Filtering Poo with Continous Flow Media Bed

My indoor system started out with a gravel bed. After repairing a leak in the 45 mil EPDM liner of that grow bed, I decided to go with a Deep Water Culture (DWC) raft.  With only one 10 wall glazed my grow bed is 30"x10 long which is a rather small 25 sq ft..  I found it easier to utilize that precious space with a  raft system.

A panoramic view inside grow room.  800 gal fish tank on left grow bed on right

But loosing the large media bed meant that I would also lose the filtering capability of the 3/4" rock media.   So I decided to build a filter using evaporative cooler pads.   This works great at first, but after a few months the fish population began to grow and the fish got bigger.   The filter could no longer keep up with the poo.   Cleaning filters everyday was more work than I was willing to do.

So I decided to return part of the bed to a gravel media, and keep the rest as a DWC grow tank.

The DWC tank with gravel to the right of a plastic fence partition

I built a partition out of plastic fencing and PVC pipe.  Filled one side with 3/4" gravel and extended the return water pipe from the fish tank so that it dumps on top of the gravel.   One thing Id like to say about that is I also used 2" pipe rather than 1-1/4" because the smaller pipe tends to clog.

At this point I began to have concerns about a continuous flood gravel bed.  RupertofOZ was kind enough to dispel my fears by pointing me toward a very good experiment done by backyardaquaponics.com.  

.

Read More..