Backyard Aquaponics
A place to discuss aquaponics

The outdoor system:
I am now closer to building my greenhouse system outside with 200 gallon tank. Finally dug a trench to run heavy duty extension cord in conduit from the protected outlet on the porch to the greenhouse. I have one 50 gallon growbed sitting on top of the tank and will arrange a 2nd growbed once I get water flowing through the system. In an effort to find cheaper/better growbed media, I have opted to use polyester batting. Two $8 big walmart bags expand to fill the whole 50 gallon growbed. I plan on clamping plastic lattice to the top if the plants show they can't get any other support themselves. Time will tell if the batting compresses once it becomes waterlogged. The system will be CHIFTPIST. I'm only waiting on rain now to fill up the system. Our city water is VERY hard and has pH too high for me to measure. Hence the stunted grow in my small system originally. Still debating on whether I will use only air pumps (like my small system) or if I will add an actual water pump, testing will tell. Important word of advice: Make your system level the FIRST time.

my growbed media research:
pea gravel. It has to be tested for pH before use. It is heavy. It is cheaper than other media.

crushed glass. Heavy. May be worth looking into if the batting does not pan out. This may also be a decently priced option compared to gravel. Glass is inert and pH neutral. The crushed stuff by the bag or yard has also been tumbled so it is rounded and will not cut you.

lava rock. Cheap, Lots of surface area. Rough on hands to manipulate. Is it this rough on worms too?? I didn't want to risk it yet. I just put some red wriggler worms in our backyard (newish home) and don't want to risk hurting any yet if I can coax them to stay in a growbed.

rubberific (rubber mulch). They advertise plant safe for 15+ years. And it may very well be but there is still the fear that chemicals might leach into the ap system if it is under constant wet use. Minimal leaching is not an issue to grass or trees and runoff but if we will be eating vegetables grown in this, we don't want to risk our own health with leaching in an enclosed system. Remember mulch is designed to handle rains, not lakes. Otherwise, it would be a great pH neutral material with a LOT of surface area for bacteria but slightly expensive. Also note that not all rubber mulch brands sink.

polyester batting. Walmart is no longer carrying the popular green label. the dark blue label seems to be the same stuff of a different brand. They have the layered quit batting (higher price) and the stuffing animal batting that I will be attempting to use. This has most surface area out of any material out there.

I would be interested in where you found the crushed glass.

My kids school put rubber mulch on the playground one year. They got so many complaints about how dirty it was, the removed it. The kids white shirts where gray after one day, and just proceded to get darker and darker through the year. Bleach did not whiten them. It is dirty stuff and unlike gravel, it cannot just be washed off. I would think as a grow media, you would never be able to see the fish.

I would worry about heavy metal leaching from the rubber mulch.

Yes, leveling stuff is important cause it is much harder to do once water and media are in a system.

I tested a few pieces of Rubberific in a glass of water for a week and there was no discoloration. Maybe they used a cheaper rubber mulch at the playground? I also forgot to list that I researched water crystals. When dry, very small space, lightweight, and easy to pack up and move! When wet, they could fill up the growbed without issue, are soft and smooth for worms, and would provide water to plants in the event of a pump failure! When bought in bulk, the price is very reasonable. I think they would be awesome for an AP system except they may also have an issue with leaching once they breakdown. I never did find documentation of how long it takes for them to break down. If it is 20+ years like most materials, then it would probably be okay, same goes for Rubberific. Without documentation, it is difficult to compare it to another item in our systems we use that also breaks down over a long period of time....PVC.

I found the crushed glass offered at a local retail landscaping company called Garden Ville. They also offer pea gravel, mulch, etc by the half yards. I opted to avoid the crushed glass originally because it was very small pieces. I am not sure if a piece or two would get caught up in the water flow. Wouldn't want fish to think it'd food.

The water crystals probably wouldn't be appropriate for am aquaponics system. I've played with it for house plants and stuff.
1- the water crystals can break down and leach chemicals that are probably not good long term.
2- Salt will cause them to break down.
3- UV will cause them to break down.
4- They don't provide much support for plants
5- I don't think a whole tub of them will flood and drain very effectively and there probably won't be much aeration getting into it.
6- Since they are transparent, sun can shine through them and inhibit the bacteria as well as the plant roots.
7- Algae will grow in it since the surface doesn't block light.

Even when using the water crystals in potting soil, you have to be careful not to use too much since they can cause the soil to stay too wet and cause root rot for many plants that don't like wet feet.

They might be fine for some house plants but the jars I have hanging with water crystals and plants in them are not thriving long term as well as the ones simply in water or the ones with perlite and water.

whats this polyester batting you speak of?

Yeah, the "water crystals" are just sanwet, it's the same stuff in diapers. It is actually water soluble as well, so in you system once enough water gets in there it would just disappear. Definitely not a choice for aquaponics. Salt prevents uptake of the water a little bit, which is why if ever someone mistakenly tries to flush a diaper you can add a bunch of salt in the toilet and it will help clear it.

My father used to work for the company that produced the stuff and many years ago I did my grade school science fair experiments with it as a fire retardant and on plant growth factors using it. We used to have large containers of this sitting in the garage. Good times.

True, water crystals dissolve with salt so any degree of salt to subdue fish stress would have an adverse effect on the water crystals. It has finally rained here this month and my system is almost full. I tested the water and pH of right around 7.0. I guess there has not been much rock dust in the air lately (limestone around these parts). Another decent rain or two and I should be able to start rolling the water through the system. I am anxious to see just how the poly batting will do once the plants get a decent size. Seems I mis titled this thread as my main tank is 100 gallons. Plus a smaller sump tank and grow beds, ah well.

Is the "poly batting" you're using afibreglas insulation batting???

If so, most of it is soaked in fire retardant... and will probably kill your fish...

Do you have an MSDS link for the product...

Not sure I understand why it is you just don't use some of the tried and tested media...

Some of the stuff suggested just sounds too suspect for me to even consider, for little benefit that I can perceive...

Sorry, just re-read and see it's a "polyester" batting....

I'd still be curious as to whether or not it has been fire-retarded....

So we finally got a good rain last week. Unfortunately it has been so long that the big tank has evaporated to less than half full. I really need to get covered rain barrels and more of them if the outdoor system is ever going to get started.

Did that rain yesterday help any? I was running around putting any container I could find under the streams of flowing water off the roof! It was a hoot. The dirt garden got good and soaked.

I really need to get some rain collection barrels. The 50 gallon tank outside the greenhouse just isn't enough. Every now and then I get close to filling up the 100 gal tank but another rain doesn't come to give the extra for the sump tank. Then evaporation happens by the time it rains again and the circle continues, uhg.

I'm happy to say I finally have enough water and its flowing through the system using a water pump. Still need to finalize what I'm using for flood tank valve/siphon. Still no rain barrel system. And now, the greenhouse is missing a window in the door, uhg! Any ideas on fixing this? The top window was shot out by a rock from the lawnmower, the same mowing that the lawnmower shot out my side truck window. Two in one mowing, what are the odds!? The old weatherstripping was toast so a new window would need a frame or something I guess. Is it easier to screw a board into the aluminum door just to cover up the hole? I want to be able to retain heat this winter.

This past weekend I was able to get a new window cut for the door. Turns out the door still had a removable window frame in it! So now I need to silicone the new window into the frame and put the panels back in the door. On another good note, I have a new prototype siphon, different design than the last one, but I'll have to leave it at that until it has proven reliable at least a month in use.