Backyard Aquaponics
A place to discuss aquaponics

Although goldfish are listed as cold water fish (and often survive fine in ponds that freeze over in winter), they can certainly handle 85degF in my experience. That's as high as I've gone, but they don't seem to mind at all.

40 deg c was my max.

Goldfish at 40degC!? Wow! That's 104degF! Not for a very long time, I assume?

Only until they were tender when pricked by a fork.....

Couple of hours a day

My nitrates have dropped from 40 to 10 in about two days. Is that a good thing or does it mean my plants are eating the nitrates faster than the system can produce them? I still haven't added any fish to the system.

You are correct, happy days

I'm planning on getting fish this weekend but I'm still working on bringing my ph down.
I read in another thread about ph that pine needles help so I've done two things, I grabbed a green branch of pine needles and stuck it in the aquarium and then picked up a bunch of the dry need, rubber banded them together and stuck them in the grow bed right underneath the water inflow.

It will be interesting to see the result

Me too, there is a Kiwi company makes a non selective organic herbicide out of pine oil. (might be just a spray though)

Okay so after letting the live branch sit in the aquarium a couple of days and the water running over the dried pine needles I've seen no real change in the ph of the system. The ph was still sitting at about 8.2, it's 7.6 coming straight out of the faucet. I'm not sure if 7.6 to 8.2 is a reasonable jump from it just being exposed to more oxygen through the pump system or if there is something else causing the increase. I almost suspect that the dechlorinator I use helps with that but I'm not sure and I don't think i want to skip the dechlorinator.

So tonight i decided to do a bit more experimenting. First I took a bunch of pine needles and stuffed them into a container and filled them with aquarium water so that it was a real tight fit and the water would have to get soaked into the needles real good. After letting that set for a couple of hours and then doing a ph test on that water I didn't notice any change in ph level. The water color didn't really change much either. So after remember an episode of Survivorman where he made pine needle tea, I decided to stick the container in the microwave for about 3 minutes, long enough to get some little bubbles going. Then I did a measurement on that and the water had dropped to a ph of 6.6.

So I suppose I could treat some of the water this way until I get the tank closer to 7. I should probably retry the first test and let it sit longer without my impatience getting in the way.

I was thinking that I could maybe set up a gallon jar with pine needles and let it bake in the sun all day, (pine needle sun tea), and use it for top off water.

What do all of you think? is it that important to get the ph down?

The only thing PH 8.2 will harm is your plants.

If you only add small amounts of water to the system, you can get away with not dechlorinating. I did'nt tell you though. Shhhh.

This depends on the amount and type of chlorine in your tap water.

Honestly I'm just kind of puzzled, everything i've read makes it sound like high ph is a rare problem and the the nitrogen cycle should be pulling it down. I'm wondering if it will go down when I add a few fish. The leaves on the tomato plant are starting to curl just a little bit but it's still seems like it's growing really fast, and ammonia, nitrogen and nitrate are still sitting at 0.

Maybe add some urea to keep the cycle going?

I'm guessing the acids from the pine needles are tannins. Probably, at around ph of 6.0 or above, they would not hurt the fish or plants, but I am speculating.

The nitrogen cycle and other organic reactions do drive down ph, but it takes months in my experience. None of my systems have dropped more than .5 in six months. Water hardness or some types of gravel may be buffering one's ph.