Progress Report - Week 8

[Andrea]

Fish seem healthy, though I did lose another this week. But she had been swimming straight at the airstone for a while, so I suspected she wasn't going to make it.

I've removed all of the aquarium gravel, and put in the last of my clay, in the hopes of having a surface to help filter the detritus without raising pH:

I also removed all of the rockwool today, transplanting those plants directly into the clay. I also transplanted the seedlings I'd started a few weeks ago. The growbeds now have about as many plants as they'll be able to fit in, once the plants get bigger:

pH remains stable at 8.1, though I am treating with small daily doses of acid. Perhaps with all the rockwool and gravel gone, it will start to lower.

Nitrates, nitrites and ammonia are good. Water is still awfully hard, but that'll clear up in time.

[TCLynx]

Water directly out of the tap will give you a false low pH reading. If you were to aerate the water for a while before doing the pH test you will probably get a much higher reading.

The trip through the britta filter brings the pH down because of the charcoal in the filter. If you have gotten rid of all the buffer material in the system and are now topping up with water from the britta, then I expect your system pH will be comming down before too long. Keep an eye on it since if the pH goes too low, the bacteria will crash. So when the pH gets down below 6.5 you will probably want to add some of the buffering gravel back in until the pH stabilizes between 6.5 and 6.8.

[Andrea]

I have tested my water. While it is about 7.4 straight from the tap, I run it through my Britta filter prior to adding to the FT, and that brings it down around 6. I hadn't thought of aerating the test water first, though it is fairly well aerated from its trip through the drip filter.

[TCLynx]

You might do a test with just some of your source water to see how much acid it takes to adjust the water before you put it in the system. I know my well water is rather hard and it took several doses of acid to bring the pH down. I was eventually able to get the water down to 7.2 but it would bounce back up to 7.6 for a time. But 7.6 isn't a bad level to have in a system as it will drop over time as the system matures.

Anyway, if you can pre-adjust some water before using it to top up the system it might make for less bouncing. I would recommend having an air stone to help aerate the water as you adjust it and then let it sit with the air stone running for a day to see what the pH stabilizes at after the adjustment.

Good Luck with it.