Backyard Aquaponics
A place to discuss aquaponics

Just remember that if you are not heavily stocked you can get by with way less than turning over the tank volume every hour, so you can cut back a bit on your pumping duration in an emergency due to low power generation in cloudy winter weather. DO isn't such an issue then either. However, it's always better to have a bit more PV power than you absolutely need, which will save you a lot of worry when the overcast hangs around for days on end.

Hi Varmint.
It's been a while since your first post, so just wondering how things worked out. You didn't seem to take into account the air pump so did you just use water jet venturi to aerate your tanks?
An alternative pump for small or ibc systems is to buy a Shogun 20W solar pump/timer/battery unit from eBay. I have operated my original ibc system with one for the last 18 months and it has not missed a beat (NB: I did need to add a second 7Ahr battery as back up for grey day periods of 4 or more days. The system is timed for 15 mins on per hour, which is enough for a low stocking rate. The price was very reasonable (about $180 AUD or $150 US) delivered).
I run a separate air pump off mains for both of my systems, which is obviously not an option for you varmint, but may well work for others looking at a 12V solar set up for a small ibc system