Added some pea gravel to the Sand System

My original load of sand over time and under pressure of water has compacted, and some of the roots were starting to show, especially when I was digging my channels around the sides. I decided to add some pea gravel to the sides to see if it might help to keep some of the algae from forming. So far, it seems to be working. It's been almost a week, and there's no sign of algae on the new pea gravel. The water seems to be flowing just under the pea gravel's surface. Plan is working!

Added the pea gravel only to the sides where the water flows around. You can see the algal mat covering the sand in the middle. Much of that sand "flooded" before when the mat built up enough around the sides when it was all just sand. 

Things are looking good, despite the lack of sun.

Progress Report on Sand System

Thought I'd post a little update on the sand system before I add in 15 tilapia to the mix. So, the growth that you see is the product of 2 good-sized goldfish - that's it. I've seen good growth in the tomatoes, and all of my seeds have germinated. I will say, though, that it seems like the seeds may have taken longer to germinate than they did in my hydroton system. Could be that the weather is the major factor in that, though, as it's been exceptionally cool and rainy this spring.

Veggies include tomatoes, green beans, edamame, cucumber, yellow squash, sweet pepper, and some basil starting to come up.

Top shot shows the grow bed when the water starts collecting. Bottom shows what it looks like after I poke a few holes in the sand with 1/2" PVC pipe. Many claim that I won't be able to keep this up for long - that the sand will compact and clog and eventually stop draining well. Maybe... but for now, things are fine with the occasional hole poking.

All in all, I'm happy so far with the sand system. Having to poke some holes into the sand to help with drainage isn't that big of a deal work-wise, but the fact that it requires any extra effort puts it at a disadvantage to my hydroton system. It will be interesting to see how the drainage fairs  over time. I think most people think it will get clogged and basically crap out. I sure hope that doesn't happen!