pH

[dolphin]

Hi, is adding lime juice to an aquarium or a pond for dropping the pH ok are there any side effects. The idea was suggested by a fellow aquarist as he tells he does it for is tetra tank. Never tried want to know does it works.

[MatsP]

It will indeed lower the pH, and I don't think it will have huge negative effects. In general, I wouldn't recommend lowering the pH by adding acid. Is your water soft or hard? Really soft water will go to quite low pH with more "natural" methods, such as adding peat.

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Mats

[Matt30]

Hi mate I use RO (Reverse Osmosis water) it has a very low PH and most LFS have it
I use half treated tap water and half RO when doing water changes but you have to experiment with the mix of the two to get the right balance of the PH in the water as different areas have different levels of PH
Anyway it works great for me.

Good luck

[dolphin]

HI
I use RO water and the reading is pH 7.0 and dh 03-10ppm. Whereas my tap water has a pH of 8.5 and the tds is 250ppm range.
I have a running water filtration total volume of water is approx 500litres and the fishes are bristlenose pleco 19no.s (12cm and above), L018 6no.s (10cm), L168 (14cm and above), albino bristlenose pleco 10no.s (6 cm), Veiltail bristlnose pleco 10no.s (10cm including their fin)and all are housed in seperate tanks. The tanks are bare bottom with lot of driftwood and caves(pvc). There will a water change of 20% everyday and about 70% weekly once. My problem is when i check the tank pH it always stays at around 7.4 to 7.6 range. Unable to drop the pH below that even when i change the water 70% it goes to 7.0 but later comes to 7.5 average. What might be the problem. And temp stays around 25.3 to 27.0 in all tanks.

And another question what is the breeding size of L168.

[MatsP]

Since your tap-water pH is quite high, I think the best approach would be to use more RO water, and less tap-water.

Really low pH isn't as important as soft water (low TDS) for the fish, and adding lime-juice or other acid won't actually make the water softer [well, technically, if it breaks up the carbonate into carbon dioxide that gasses off, it will soften the water - but you are left with roughly the same TDS-level, which is the key point of making the fish comfortable].

L168 at 14cm should be about ready to breed. May just need soft water....

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Mats

[dolphin]

Thanks Mat

[PseudaSmart]

You had one question in your post still not answered. Why does the Ph return back to almost the same after adding RO water. There is a lot of technical information on the web but I will try to offer a simple explination. Since RO water has no hardness it has no ability to hold a stable Ph. If you airate RO water the carbon dioxide in the air will be absorbed into the water making carbonic acid. This is why RO water measures acidic with a ph test. To maintain a stable Ph either high or low requires the addition of a 'buffer' It takes a while to understand how they work.

So the short answer is that pure RO water (no hardness or buffer)will affect the Ph of the tank short term and then bounce back. If too much RO water is used the tank will be more at risk for a ph drop because the total hardness of the water was lowered. It is for this reason a buffer addititive is required or mixing the RO water with tap water.

To lower the Ph of some tanks for breeding I use phosphoric acid because it is a 'gentle' acid and the my plants handle the extra phosphate. This method is not recommended for beginners or average aquarist as there are a lot of calculations.

[MatsP]

Good point, Likesloaches.

I would also say that if the water is soft enough (no hardness/KH or other alkaline buffers), then the pH will eventually drop to about 4.0.

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Mats