Backyard Aquaponics
A place to discuss aquaponics

You can also use softened water as your top off. The softened water will have a lower buffering capacity, but will be salty.
I think collecting rainwater (natures distilled water) for top offs is the way to go.
I'm working on this too, so I'll try to let you know how things develop.

We don't use a water softener, and the ro filter we have only produces a few gallons a day. I could collect rainwater, but not leaning that way. The house roof is composite shingles, and the FH roof is steel with no gutters.

Coach - what's the bio-load at this point, and how's your gas exchange? You need some bicarbonate buffer for the bacteria to function well.... 3 dKH is great for that. I'm betting that your fish load is light, and aeration is high right now. That means there is little CO2 in the water.

Generally, pH is a function of the amount of dissolved CO2 in the water, and the level of bicarbonates (i.e. your 3dKH). I'm betting you have very little dissolved CO2 in your system. Once you have more fish load, the pH will drop to 6.8-7.2 region.

PS: The bicarbonate buffer is slow - that's why you saw the pH fall to 7.97, then creep back up to 8.3

smatthew. yes on all counts. only 140 feeder goldfish, less then 1" each. total weight probably under 1/2 lb. Thanks!

Knowing the buffer capacity seems to be not very important when you're doing small, incremental changes. The pH has taken a couple days to stabilize after each adjustment.
I've brought my pH down from 8.2 to 7.5 or 7.6 currently by doing water changes (~10% at a time) and using rainwater (pH 6. to refill

What test kit are you using for your Gh and Kh?

Might want to check the Kh again too.

The cheap API kit...not sure how accurate it is. i was thinking of using rain water from the roof. The galvalume should be OK?

Ph is staying fairly steady between 7.4- 7.7. Fish are doing Ok. The new large ones aren't eating at the top yet. It takes them a while to get used to the clean water. They do eat, but only after the food starts to sink.

pH sounds alright at the moment.



http://www.aquaponiclynx.com/why-does-the-ph-keep-rising

Might want to PM TCLynx she's here on BYAP as well, and ask her what she uses or post the question on her system thread.

Seems to be stable. Only feeding a few ounces per day. Big guys are not really settled in and eating yet. Once they do, I'll be more like 8-10 ounces. Got the welding done on the shelving brackets for breeder aquariums. Orders some more air stones. Wondering if I should drill holes in the aquariums and make then recirculate with system or just put on some small filters.