plant safe pH buffer

[twincessna340a]

I have a 55g mixed biotope lagoon setup with 1x pictus, 4x upside down cats, 1x oto, and cherry barbs in the near future. I also have 3x Cyperus Helferi and an Amazon Sword with small and medium pieces of natural driftwood with silica substrate. My last water tests were 5 dkH, 8 dGH, and pH of 7.6 at 77*F. I'm not worried about pH going up as my two 'neutral tanks' with gravel and artificial decor have remained at 7.6 for weeks with similar KH and GH readings. I'm lucky that my tap is relatively soft with it coming out at 5 dkH and 6dGH.

Bottom line I'm looking to lower my pH by 1 to 6.6/6.5 which would put CO2 levels in much healthier levels for my plants...not to mention my fish would probably be a little happier. I really want to avoid messing with chemicals like pH Down and start a never ending battle with pH fluctuations. I'd really like to go the buffer route like I did with my Rift Lake tank which has been working great. API's pH 6.5 is great, except it's a phosphate buffer which is bad for my plants.

Any suggestions on alternate buffers or a simple CO2 system?

Thanks!

 

[jeremyblevins]

A stable ph is a good ph for most fish. Why do you want to lower it?

 

[JohnPaul]

Basically your options:

1. Regular CO2 injection, which will naturally lower the pH some.
2. Depending upon your filter, putting a good-sized chunk of peat in it so that all the water being filtered also moves through the peat. This will acidify and soften the water some.
3. Ripping out your current substrate and replacing it with ADA Amazonia (I or II). While the most drastic measure, it is the most likely to be effective. I know a lot of people who specialize in the soft/acidic water dwarf shrimp (Crystal Reds, Tigers, etc.) and basically every single one of them uses Amazonia as their substrate, and that combined with either DI water or very low KH water is going to lock in your pH right in the mid-6's. Just be aware that when Amazonia is first added to a tank it causes a big ammonia release so you need to keep your fish somewhere else until that phase has passed.

Those are your only options (as far as I know) for adjusting the pH down naturally. #3 is the most drastic but the most likely to achieve complete success; #1 and #2 can both be helpful, especially if you did both together, but aren't necessarily a guarantee of success though at the very least they will get you closer to the goal you desire.