Do plants lower ph? Here's my situation....

Moleen

Hi,

My tap H20 always tests at least 7.6 for PH...could be higher. My last H20 change was this past Monday. I used 4 gallons of tap H20 and 3 gallons bottled H20 (both treated with Prime). The bottled H20 I use has a PH of 6.4. I tested my PH today and it tested 6.4. Do my plants lower my PH? I ask this because I don't always use bottled H20. I do a 7G H20 change weekly on my 20GL tank. I'm just curiuos why my tank test so low for PH when my tap H20 tests so high?

Thank you for any thoughts! Kathy

PENN

plants lower it a lil. i think it goes down a little as the water distills also

Byron

Live plants tend to maintain stability and this includes the pH, but there are several biological processes ongoing in an aquarium with plants and fish that are all factors in this balance. The ph will naturally lower as the water becomes more acid, but this is influenced by the hardness. I suggest you have a read of this article that explains this:
Water Hardness and pH in the Freshwater Aquarium

If you can provide me with the numbers for the hardness, both GH and KH, of your tap water, I may be able to apply this to your situation a bit more.

Byron.

Moleen

Hi Byron,

Now bear with me.....I'm still very new to this, but I'm a fast learner!!!

Went into Boston today to a very reputable LFS. I had them test my tap water (I let the water sit out in a glass overnight). They got 7.2 for PH. I just this minute tested my tap straight out of the faucet and got 7.6. They told me my H20 is very soft...testing around 25 for KH?

I just did a 7 gallon H20 change (tap treated with Prime)

PH has just tested 6.4
Ammonia has just tested .5
0 nitrites
0 nitrates
GH 75
KH...0-40 ? (test strip)

Seachem Ammonia Alert on tank still reads "Safe"

They recommended Seachem Equilibrium and Seachem Alkaline Buffer, which I bought but haven't used yet because on the label of the Alkaline Buffer bottle it say" if H20 is soft or not well buffered, use with Acid Buffer.....which I did not purchase so I'm not sure whether to use it without the Acid Buffer?

OMG! LOL! I am so frustrated!!!! I don't understand why my ammonia is still at .5????? I have a bazillion plants that are thriving! I bought 7 more today. I don't understand how I can pour 7 gallons of 7.6 PH tap H20 into my tank and still get a reading of 6.4????

All I know right now is my fish seem just fine....active with good appetites...no visible signs of stress?

Maybe I should just crack open a beer and celebrate that my Patriots just won and are a couple weeks away from winning the Superbowl!!!!!!!!!
They

Byron

If you read the article I linked you should have a fair understanding of why the pH in the tank is lowering. But to save time, I'll summarize. The GH and KH numbers for your tap water are low which means soft water. The KH is the "pH buffering" component in all this, and it is quite low at 25 ppm (must be ppm, can't be degrees or it would be liquid rock). So the pH in the aquarium will lower as the CO2 produces carbonic acid. My tap water is pH 7.0 to 7.2 with even less GH and KH than you have, and my tanks naturally have a pH around 5 if I just leave them alone; and I change half the tank water every week with straight tap. Once an aquarium is established, the pH will tend to remain stable and when fresh tap water is added during a water change, the pH will rise very slightly and then over the next few hours lower back. This is not an issue for fish, but I won't go into all that.

Assuming you have soft water fish, this will be fine for them and your plants. I would not mess with it at all. I have Equilibrium and am using it in one tank as an experiment. My water is softer than yours, which means no calcium and magnesium, and these minerals are not available in sufficient quantity in basic fertilizers like Flourish. My swords are showing calcium deficiency, and there are a couple of ways to deal with this, one being Equilibrium. I am using other methods in other tanks. But if your plants are fine, and from your GH I would say your calcium and magnesium should be sufficient--forget the Equilibrium and the other stuff; they will get very expensive long term. Again this assumes you have soft water fish.

Livebearers and other fish that need medium hard or harder water with a basic pH will not last in your tank any more than in mine. Rift lake cichlids would also fail. The article suggests ways to deal with this if it applies.

If you have not used the two buffer products, take them back and ask for a refund or a credit. Assuming soft water fish stilll...

And please read that linked article, it covers this better than I can here and will help you.

Byron.

Moleen

Hi Byron,

Thank you soooo much for your expertise....but I don't have "soft H20" fish.......I have 1 female Platy, 1 Black Sailfin Molly and 4 Pink Cory's. The staff at the Boston LFS told me that my Platy and Molly do better in harder H20 than mine????? I don't know about my Cory's. All my fish "seem fine", but if there is something I can do to keep them from suffering and dying please tell me!!!! Gosh, I'm so confused!!! I just want the best for the little creatures I have in my care! Thanx a million Byron!!!

Byron

Well, this time the fish store is correct. And you have two options. One is to return the Platy and molly and go with soft water fish (the Cory is such). This is the easiest, as you can use tap water (with a water conditioner obviously) for water changes and the fish will be fine. Many of our members would give almost anything to have your water; the variety of soft water fish is almost limitless.

Or, if you want to maintain livebearers, the water has to be made harder. Rather than mess with expensive chemicals, the easiest way to do this is with a calcareous gravel or sand. Limestone, dolomite, aragonite and coral are primarily calcium. You can buy sands and gravels made from crushed coral, aragonite or dolomite. These are intended for marine tanks but they work well in hard water freshwater fish aquaria. I've done this myself for livebearers and rift lake cichlids. Mixing in a fine gravel made from crushed coral and aragonite (CarribSea make one that I am using presently) with ordinary natural gravel so they will blend and appear uniform is the easiest way. It really doesn't matter how "hard" the tank becomes, mollies even occur in brackish and marine environments at times.

Livebearers kept in soft water will not last. Molly frequently develop sin problems, fungus, shimmying, due to the lack of mineral. And Platy may go a bit longer but the same will happen. Followed by early demise.

Byron.