Backyard Aquaponics
A place to discuss aquaponics

it sure looks like your media is affecting the ph..

my system started outside, for 6 months the ph was pretty consistent at 7.6, after moving half of it to the basement, i still have a ph of 7.6 or so.. still getting decent growth, and fish don't seem to mind

Seeing as none of your gravel bubbled too much with the vinegar, you will probably be ok over time.

Yes, your well water probably is affected by the dissolved CO2 right out of the tap and I expect the pH bumping up to 8.2 after being in the system is mostly due to the well water but your media probably is affecting it some. My well water will measure a pH of 7 right from the tap but once put in a new system and allowed to circulate (even a system with no chance of lime) the pH will be up between 8 and 8.4 depending on time of year/rainfall. If by adding acid you can bring the pH down to 7.6 and get it to stay there for a few days without needing to keep adding more acid every day, then you should be just fine. My big system spent it's first year between 7.6 and 8. Over time once your bio-filter establishes and is working hard, the pH will drop and what little calcium carbonate is in your rocks will be dissolved as a buffer and eventually you may find you need to add some lime or shell grit to keep the pH from dropping too low. I would avoid the types of media that reacted the most when put in vinegar when you fill up any beds that are not done yet.

Biggest drawbacks to a system running a higher pH at first is the toxicity of ammonia at a higher pH so fishless cycling would be a really good idea and then the difficulty for the plants to uptake Iron at a high pH so additions of chelated iron tend to be needed more in a high pH system.

For more discussion on pH issues for this system (related to the posts above) see this thread - http://www.backyardaquaponics.com/forum/viewtopic.php?f=1&t=8692

For a discussion on fishless system cycling methodology for this system - see this thread http://www.backyardaquaponics.com/forum/viewtopic.php?f=1&t=8730

Update: - yesterday we started cycling the system using humonia. We also planted some seedlings (tomatos) and a variety of seeds. Exciting times - though we have mild expectations at this stage!

At present we have three of the six grow beds online and I am starting to collect gravel from the local river to bring the rest online over the coming weeks. We still have pH issues - though advice from the forum has been to give cycling a shot and see how the system reacts, so that is our current plan.



Please see the previous two posts for discussion on cycling methodology and pH isssues.

Water quality readings during cycling:

---------------------------------------
Date------pH-----Amm---Nitrite----Nitrate
---------------------------------------
Dec20-----8.2------0-------0------10---
Dec20-----added 585ml of humonia (3 day old)
Dec20------------0.50------------------
Dec21------------0.25-----0.20-----15--
---------------------------------------

System update;

The system has now cycled (about a month ago) and we are still fishless. Though we thought we were going to get our first fish last week - well this is Guatemala. The fish proposed are called Mujarra and though we haven't seen them we think these will either be Tilapia or Bluefin.

The absence of fish hasn't impacted our plant growth. The humonia added during cycling has provided an abundance of nitrates and the tomatoes and beans have really thrived. In recent days the swiss chard, lettuce, spring onions, watercress and broccoli have started to take off.

Vegetables were planted from seed four and half weeks ago and poked there heads out around three weeks ago. pH is still at 8.2 but doesn't appear to have dramatically effected plant grow to date.

Looking good.

In the future if you could re-size your picture a bit smaller it would make reading the posts much easier without having to scroll sideways to read each line.

Not sure if this a bit of over-kill but decided to build something substantial to a) support tomatoes and beans etc and b) provide a support structure for some roofing for the rainy season. I don't know if the aquaponics system will handle the heavy rains better then the soil garden we had last year but thought I'd make a pre-emptive strike....

So the frame is made from 3x 6m lengths of 3/4" PVC pipe and a single sheet of reinforcing steel mesh. Minor effort required to bend the steel and make the two short cuts with a hack saw. The PVC border provides little structural strength but does keep everything square and tidy. At present the steel/PVC is zip-tied to the timber frame in four locations.

Still some sharp edges (at head height) to clean up and the structure may require some guide wire support when roofing material is added. Also may add some "windows" in the mesh to provide better access to the grow beds. Tomatoes and beans have been strung up on some thin rope to provide support.

Everything seems to be going through a growth spurt right now - so it's been a pleasure to sit back and watch....

'allo?