pH crashing - peat moss issues?

[wojo93]

Approximately 3 weeks ago I set up a new 10 gallon tank. You can see the specs in the 'My Tanks' section of my signature.

When preparing the substrate, I decided to use Shultz (Profile) Aquatic Plant soil. Prior to putting down the substrate, I added a light dusting of Sphagnum Peat Moss. After everything was set up for about a day (pre-planting), I checked the water conditions to make sure everything was status quo. The pH reading was approximately 6.6! (tap water pH: 7.4). Assuming that the peat was causing the pH drop, I immediately attempted to vacuum the majority of the peat out of the substrate. Since this didn't seem to be working, I removed the water & substrate, and rinsed it thouroughly for about an hour. After I set it back up, water conditions stayed the same with the pH eventually giving me the lowest possible reading on my test kit (6.0). Similarly, KH has gone from 5 degrees (tap) to unmeasureable.

The tank is now planted... and doing rather well. However.. I'm leary with regards to fish. I purchased a pair of Blue Rams that are spending their manditory 2 weeks in quarantine and would like to add them to this tank (even if the pH stabilized at 6... they'd probably dig it). But the tank is extremely unstable due to a lack of KH buffer. A recent 10% water change instantly brought the pH up to 7.4, only to have it crash back to 6.4 within a day or two.

I could add lime to bring the pH up... but that doesn't solve my buffer issues.
I could add a commercial buffering product to keep the pH stable.. but this doesn't sound like a good long term solution.

I'm looking for suggestions regarding how to remove the effects of the peat and somehow get back to normal pH/KH levels.

 

[daveedka]

I could add lime to bring the pH up... but that doesn't solve my buffer issues.

How is it that adding lime would not solve your buffer issues?

Commercial buffers designed to up PH are typically sodium Bicarbonate (baking Soda) and they work. But of course so does baking soda at a much lower cost.
Lime is Calcium carbonate, so is crushed coral, the Carbonate is the Kh you want. If you don't add KH you generally can't raise PH. They go hand in hand.

I'd start with multiple small water changes with Baking soda added to the change water and get your KH up to about 3+ that way. then add a small amount of Crushed coral or lime to your system to maintain it. If the tap really is 5 DKH then you really shouldn't have any truble maintaining Kh via water changes. But your tap PH should come out about 7.8- 8.0 once the water has had time to gas off good (set some in a shallow bowl overnight and then re-test) I'd definately take a sample to the LFS and ask them to test Kh just to verify your test is accurate. If the tap truly is 5 frequent water changes will compensate. Peat has a limit to it's ability to consum KH so after a few weeks it will stabilize out. until then it may take a little work to keep things in the safe zone.
Dave

 

[wojo93]

Thanks Dave!

I'll give it a shot w/ the baking soda. How much would you add for each gallon of water for the water changes?

And for the crushed coral.. would it work to put small handfull in an old nylon stocking tied up and placed in the HOB filter? That way the water would flow through it.

 

[djlen]

The peat should not be causing that much of a drop in pH or kH. Something doesn't sound right here.
You can use a combination of Baking Soda/crushed coral to bring up and stabilize kH.
Drop a 1/4tsp. of Baking Soda into the filter and test for content after 2 hrs. Add more in 1/4 tsp. increments if necessary.
At the same time your idea of a handful of coral in the filter will help long-term to stabilize kH.
Look for a kH of 4 - 5°.

Len

 

[falcon]

This doesn't make sense. I would investigate why your kH is non-existent. Have someone re-check your kH and pH. Nothing in your tank indicates why your pH should be that low.

Do you have a water softener in the house?

I would do a test. Fill a glass with tap water and leave it overnight. Test it the next day for kH and pH. This is what your aged water will be. If the test comes with a pretty low pH, around 6.7 or so, it would mean that you might have to age your water to avoid the initial swing. This still doesn't explain your kH issue - why 0 reading.

 

[RTR]

Utilities frequently add phosphate to the water supply if KH is low to maintain a safe alkaline condition in the pipe network (copper is resistant to alkaline water). Unfortunately, those salts act just like many so-called "aquarium buffers", being good for 1-3 days and then bingo, back to baseline.

 

[Kissofthegorami]

If you can't get the PH up at a stable rate, embrace the low PH! Many people desire low PH for amazon fish... angels, cardinals, neons, rummy nose tetras and most other tetras. Low PH can be a good thing. Cardinals can take PH as low as 4.0!