Freshly cut spiderwood and Low PH crash
I wanted to post my experience on this forum so anybody with spiderwood or any ph altering driftwoods can not make the same mistake as I just did this past week.
I’ve had a new planted shrimp tank maturing for two months now with spiderwood, pre aged Ada Amazonia, moss and bucephalandra. The spiderwood branches however were taking up a lot of vertical space in the tank and I got tired of trying to work around it during maintenance. I decided to lower the water level, remove the driftwood and use hard clippers to clip off all the vertical branches to open up more open space in the tank for plant growth and water.
Spiderwood has a low levels of tannins especially after boiling the wood and having it mature in the tank a few months. It can cause bacterial blooms and white fungus and cloudy water for a while in smaller tanks like mine. But I did NOT however predict that trimming the branches off would cause what happened afterwards.
Day 2 after spiderwood trim, exposing 6-7 open stumps, the ph that was before nicely buffered at 6.2 for quite a long time dropped to 5.8 and falling. A few days later I did a 40% water change to remove debris and fungus and raise the PH back up and within a few hours after the water change the PH crashed down to 4.7 and dropping (only had one Amano shrimp to test the tank parameters but he didn’t make it past the first day even after removing him). I decided to emergency add a spoon of baking soda (KH 1-2) to drive the ph back up above 6.0 to prevent my bio filter and bacteria and plants from dying which they were. After that the water cleared overnight and the ph is where it needs to be for now but unfortunately the baking soda will wear off as the Ada Amazonia absorbs the KH and the PH will drop again so I am monitoring it.
The problem is I have no idea how long the cut driftwood stumps will keep leaching acidity into the water column and how long it will take for the PH to stabilize back up to 6.0-6.5 again. It makes sense that a little acidity would come fro the cut wood but PH 4.7 and lower seems crazy!
I’ll note that no other changes to the tank were made besides this and water changes. The Amazonia was buffering my ph at 6.2 before the crash and the RODI water (for WC) has a ph of 6.4 after remineralized with Bee shrimp GH+. Kh 0.
I use a combo between my API test kits and a digital Ph probe meter to watch actual ph values especially when they get below 6.0. It is calibrated.
I mostly wanted to tell my experience because I tried doing forum searches online before attempting to trim the driftwood and didn’t see anybody’s experiences with doing this and I wanted to get it out there so people can avoid the same mistake or atleast know what to expect if they do.
The trimmed spiderwood might cause acidity problems for longer than I can handle and I might have to remove the driftwood and replace it with cholla or mayalsian or lava rock instead. But I will continue to be patient and see what happens. I am hoping that after a few weeks or regular or more frequent watwr changes the extreme acidity will be gone.