Low pH in both tanks...add crushed coral?

[Karackle]

I have 2 tanks, a 5g and a 20g. The 5g has natural colored aquarium gravel, a Red Sea nano filter, planted with purple cabomba, wisteria, crypt wendtii and an Anubias. For fish it has 1 Male Betta and 2 otos. There's also a piece of driftwood which I believe is the pH lowering culprit. The tank has had a few problems recently and is going through a bit of a mini-cycle. Ammonia is ~.25, nitrIte ~.25 and nitrAte is about 10 (from plant tablets). The 20g also contains regular aquarium gravel, is heavily planted with Wisteria, Crypt wendtii, Crypt spiralis, purple cabomba, and 2 different anubias sp. It has a Marineland Penguin 100 Bio-Wheel HOB filter. For fish it has 3 female bettas, 3 zebra danios, 6 glolight tetras, 7 neon tetras, 1 female guppy and 1 clown pleco. In this tank ammonia is consistantly 0, as is nitrIte, nitrAte is ~20. Both tanks are low-light. There's a piece of driftwood in this tank as well. For more info on the tanks my journals can be read here: http://www.aquariumadvice.com/forums/f19/my-5-gallon-journal-101228.html and here: http://www.aquariumadvice.com/forums/f19/my-20g-planted-journal-56k-101691.html

The problem I am having is that the pH in both tanks is 6.0 or lower (6.0 is the lowest the test reads). The water coming out of the tap is 8.4 - 8.8 (I bought a high range pH kit to test it more accurately). Water changes don't seem to be doing the trick for raising the pH, and I worry that because of that, the PWC are causing a fluctuation in pH that's not great for the fish. To combat the pH lowering effects of the driftwood, I'm thinking of adding some crushed coral to the filter to raise/buffer the pH. Is there any reason this is a bad idea?

Any input would be greatly appreciated. Sorry the post is so long! I was trying not to leave anything out!

 

[Purrbox]

Can you test both your aquarium and tap water for KH? This would really help us figure out what's happening with your pH levels. The driftwood will lower the pH some, but this sounds too drastic to be just a result of the driftwood. Did the 5 gallon have the low pH before the mini cycle (cycling can mess with pH test results)? Are you adding any chemicals other than dechlorinator? Some plants can strip the water of carbonates, but I don't recognize the species that you are keeping as ones that tend to do this.

Adding CC may be the solution, but I think it would be wise to figure out what is causing the low pH before messing with it.

 

[Karackle]

I've never had problems (that i've noticed) with the pH before, so I don's have a KH/GH kit, but I can pick one up and post those parameters as well. Last time I noticed the pH was low, it was higher in the 5g than it is now (6.8 then), so the lower pH could be a result of the mini-cycle and recent plant/fish die-off in there, As for the 20, it's remained at 6 since last time I looked at it, that one has the malaysian driftwood which I know is a pH lowering culprit, possibly not by THAT much though? So i guess i'll have to get out and purchase a GH/KH test kit. I've been sick, but i'll try to get to the store tomorrow. As always Joy, thanks for the input!

 

[Karackle]

And now the moment I know you've all been waiting for! Pre and Post water change results!

5 gallon:

Yesterday
before 50% WC:
Ammonia & nitrIte ~.25, nitrAte ~5, pH ~6

Today
before 50% WC:
Ammonia & nitrIte between .25-.5, nitrAte ~10 (i added fert tabs), pH ~6

after 50% WC:
Ammonia & nitrIte between betweem 0-.25, nitrAte ~5-10, pH ~6.4

20 gallon:

Yesterday
Ammonia & nitrIte = 0, nitrAte ~20, pH ~6

Today
before 25% WC:
Ammonia & nitrIte = 0, nitrAte ~20, pH ~6

after 25% WC:
Ammonia & nitrIte = 0, nitrAte between 10-20, pH ~6.2 (between the yellow which is as low as it goes, and the 6.4 which is the next step).

Because just after the WC's the pH IS a bit higher, but I did a 50% WC on the 5g yesterday and today PRE-WC it was reading at 6 and post 50% it was reading ~6.4 I'm going to check them again in ~30 min and see where they are, see if they're really changing that fast. I wish i'd taken a directly after WC reading on the 5 yesterday, but since I can't change the past, i'll move forward from here

 

[Karackle]

Well, about an hour later, pH's are the same as just after the WC, 6.4 in the 5g, ~6.2 in the 20g.

 

[Karackle]

Just a quick update, I checked again this morning and pH is back down to 6.0 in both tanks...

 

[Karackle]

Ok so I went to the fish store and had my water tested in the 20g (2 of the fish that i got on friday died so i brought the fish and a water sample in) and apparently my pH is actually 5 and my hardness is effectively 0!!! YIKES! He suggested a 5g water change every other day to bring the pH slowly up and add hardness, but I am going to bring a tap water sample in tomorrow, as well as a post-WC sample in to him to test it, and to see if my water is really that soft coming out of the tap. If so, then i think it's time to put a bit of crushed coral into the filter to help buffer and add some hardness...what do we think?

 

[Purrbox]

If your KH is at or near 0 this would explain why you've been having such a hard time getting your water stabilized. It's possible that the way in which you water is being treated has changed without any notification.

 

[thatmagicguy]

I moved to my property about 15 years ago and when we first moved here my well water had a pH of 5.5 and 0 hardness. It was wonderful for breeding my neons, rasboras, and other soft water fishes but intolerable for maintaining fish long term.

Fortunately we have since had a new well installed that taps the florida aquifer and now we have the standard hard water.

If you are going to attempt to change the water's buffering capacity, do so in a separate container, perhaps a 55 gallon drum or rubbermaid container. This way, you can manipulate the parameters to your preference, and then add this water when you do your weekly water changes. This will allow the main tanks to be slowly raised to an acceptable level, consistantly, and over a period of time the desired levels will be maintained.

Don't try to manipulate the pH and hardness in the main tanks with fish in them, the fluctuations may stress the fish out and you will be dealing with a disease outbreak.

Bill

 

[marchmaxima]

Know how your feel K.... I have KH 0 and GH 0. My PH out of the tap is 6.8 and the PH in the tank is 6.0 possibly lower. Upon 30% water change, it goes up to 6.4 but doesn't stay there long.

Buit my fish don't seem affected, so I haven't done anything about it ...... yet....

 

[Karackle]

Ok, I bought a KH / GH test kit today. I couldn't find SeaChem "equilibrium" but I found SeaChem "Alkaline Buffer" that says it raise the KH, is this t he right stuff?

So i tested KH and GH of my 20g tank and my tap water:

Tap Water:
KH - about 3 dKH
GH - about 5 dGH (not sure if that's how to write that)
pH - 8.4

20g Tank:
KH - about 0 dKH
GH - about 11 dGH
pH - about 6.2

After 25% WC and 1/4 dose of SeaChem alkaline buffer:
KH - 2-3 dKH
GH - 8 dGH
pH - about 7.2

So the crushed coral seems to have successfully raised the GH (by too much?) the KH seems to decline incredible rapidly though, should I add the SeaChem "Alkaline Buffer?" or wait for a couple more water changes?

Thanks!

5g stats to come...

 

[Purrbox]

With a dKH of 3 your pH would normally be about 7.5. There's probably some disolved gasses or some such in your tap water that is messing with your pH reading straight out of the tap. Letting it sit for 24 hours before testing will allow any gasses to escape so that you can get a true reading.

It obvious from your initial readings on the 20 gallon that something has caused the KH to be removed. Driftwood could be part of this, as could excessive build up of mulm in the substrate (but then I'd expect higher Nitrates), or plants that break down KH for the carbon. It looks like the buffer did the job of raising the KH and pH, although I would recommend changing it in much smaller increments in the future to avoid shocking your fish. Make sure to remember to add some of the buffer with each water change as necessary.