Backyard Aquaponics
A place to discuss aquaponics

I was reading a post a while back that Janet wrote. she said she thought lava might be a bit sharp for plants to grow directly in. Has anyone had any experience there? That would be a real downer as lava is so easy to get here.

Tilapia can take a wide range of pH (6 to 9) and be pretty happy. Your bacteria will appreciate the higher pH, too. When you get plants, they might appreciate something lower, but don't worry about that now. pH will drift down a bit as your setup matures anyway.

What concerns me is the reading that you don't have: ammonia. Given that you have a stressful level of nitrite, I have to assume that you have ammonia in there, too. At the higher pH that you have, it doesn't take very much ammonia to be very harmful. I would do another water change (or two) if you can. You need to get nitrite and ammonia down. If you can use rainwater, that would have the side effect of softening the water, and maybe letting the pH drift down, too.

I'm not sure about reducing hardness by adding salt. Folks here seem to use salt for its medicinal qualities.

Rub the lava rock on your arm. Does it scratch you? If not, I really think it would be fine. Mine would scratch. If it does scratch, try it anyway. It's cheap and easy.

Thanks for the advice.. I will dor that. rainwater is hard to come by here as we are now going into our dry season but I will see if I can get some pond water when I go to get more lava rock.

Thanks

wanna know how to save your hands re: planting? Use seeds! Lettuces germinate really well in AP as do tommies,and cucumbers, I even have a couple of celery popping up. Also, corn 100% success in germination. Just sprinkle the seeds over and make sure they get down far enuf to get wet at the top of your flood cycle.

well, I can't wait to plant but don't think I better till I get the water situation straightened out. Would it pull the nitrates down to plant some plants in the water? Floating veggies or regular water plants? Both are an option for me.

yep, the plants will take the nitrates out of the water, whether they are planted in rafts, or in gravel etc

I will try that then.

Well I did a reading again and the ph went up again to right at 8.0.
Alkalinity and hardness are at 300 nitrite at 3.0 and the nitrate at 20. The nitrates are the only number moving down rather than staying steady or increasing.

Water is clearing and the fish are very actively swiming. They don't seem stressed but then what do I know?

Besides water changes, what can I do to move the ph down? Tap water ph is 7.0 but it VERY hard and Alkaline. I asked earlier about using salt to make the water softer. Any idea how much per liter and should I look at using an acid to move the PH Down? I will do a 25% water change in the morning Help!

Well I think I have an idea on the ph but I still wonder about the salt though with the hardness.

If your tap water is 7.0, how is your tank getting up to 8.0? Do you have crushed shell or coral in it? If so, get it out.

I would keep doing water changes and cut WAY back on feeding the fish. They can go several days with no food without harm. You need to get the nitrite (and ammonia) down before you fret about the pH. Like I said, your tilapia and bacteria won't mind a pH of 8.0 at all. They will mind if you go bouncing the pH up and down.

no shells or coral. Could the lava be doing it? Will do a water change today. 25%.

if the tap water is very hard then water changes might not actually help unless you can use another source of water.

Janet is right, cut back on the feeding as any ammonia spikes at this PH (8) will be more dangerous

Do a rain dance. Get rain water.

Well I did a 25% waterchange and added 1lb of salt to the tank. Ph came down to 7.5 nitrate down to 2.0 and hardness down to 250. I also added another pump to the tank just to meove the water around some and the fish seem to love it. They are more active now than I have ever seen them. If a leaf falls in the tank they are after it.

I have a compost heap where we have been trhowing all our veggie scraps. Lots of things growing there so I went out and dug up some plants to put in the growbed and to float in the tank to help with the amonia and nitrates. I have a potato, some red beans, a stalk of cilantro, and what appears to be an avocado tree in the growbed. they aren't droopy so they might be wanting to take hold. Time will tell. Thanks for the help.