ph changes due to Co2

[houndour]

I've been testing my pH before the lights go on and just after they go out. And it's 6.4 in the morning and 6.7 at night. Is this OK?

My tap water is 7 to 7.5 (I'll have to test with the more accurate kit to get a more accurate reading).

 

[Jen]

Mine went from 7.4 to 6 over night. All my fish seem fine, no noticeable problems. So as long as they are still eating and acting as they have in the past I would say you are ok. I was really freaking out when it first happened. and since yours is a much smaller change I would think you are ok.

 

[guppygirl]

Yeah, I'm wondering the same thing. If you have a DIY sytem, you can't really stop it at night, will it be ok? Or will the pH fluctuate? My pH is at 7.1 now, and KH is at 2.

 

[Yenko]

Some fluctuation is normal with all CO2 systems except those that use an electronic PH probe to constantly monitor the PH of the water and adjust the flow of CO2 from a tank accordingly. These are not cheap, and not nessesary in most situations.

 

[Ob1]

Hi houndour

That is a large shift in Ph what is your Kh? also the first question you may want answered is Are your fish happy in low PH.. some may not like the low PH never mind the PH shifts but on the positive side fish can adjust to PH shift as long as it is changed over a period of time. Keep an eye on Ph sensative fish i.e Herlaqiuns, they will start to swim very fast (darting) all over the tank looking for better water (ph)

Hi guppygirl

A lot of people will may make comment on your Kh, being so low. however as long as you are changing water regluar you may able to maintain the Ph - I have just re-read your comments - If you move over to additional Co2 in your tank then ph and kh become really important otherwise just keep up the water changes - just in case

cya

 

[houndour]

I don't know what my KH is yet. I've been to 3 fish shops in the last week to try and get a kit, but I've had to get one on ebay, but I don't expect I'll get it for another week as they don't accept paypal.

I have 5 cory metae and 3 botia striata in my tank, but the CO2 was already running before they were introduced. The fish have only been in since Wednesday.

The corys seem happy enough, busy bodying around all the time and sifting through the sand. Although they have been swimming up and down the glass in one corner for hours at a time...is this a bad thing?

The botias on the other hand seem pretty laid back (just swimming fast when I scare them when I get too close to the tank). They have made one the rocks their territory and spend their time on top of it when they aren't look for food.

 

[konrad05]

I have a digital pH probe and I notice a drop in pH, which is what should happen since plants produce CO2 at night which converts to carbonic acid in water, hence making it acidic (lower pH). I've seen my pH drop fro 7.8 to 6.5 over night and fish have been okay so I wouldn't worry about it as others have mentioned. HTH!

ps. you can add a few tblspoons of baking soda to help raise the KH so to prevent a drastic change in pH.

 

[guppygirl]

ps. you can add a few tblspoons of baking soda to help raise the KH so to prevent a drastic change in pH.

Ok, I think I'll do that. How much do I add?

 

[konrad05]

Tablespoon or so? Try to dissolve it in some water first then pour it in, my fish eat the undissolved balls of baking soda occasionally...not sure if it's good for them...

 

[iggy01]

ps. you can add a few tblspoons of baking soda to help raise the KH so to prevent a drastic change in pH.

Ok, I think I'll do that. How much do I add?

Just a word of warning. 1 teaspoon of baking soda will raise KH by around
4 dH per 50 litres of water. You might want to do a calculation before you add it.

Good luck!

 

[konrad05]

ps. you can add a few tblspoons of baking soda to help raise the KH so to prevent a drastic change in pH.

Ok, I think I'll do that. How much do I add?

Just a word of warning. 1 teaspoon of baking soda will raise KH by around
4 dH per 50 litres of water. You might want to do a calculation before you add it.

Good luck!

Is that based on distilled/tap water? I'm sure that if you run the same test with nitrates and different ions in aquarium water, it should probably be a lot less than 4 dH for 1 teaspoon.

Guppygirl - just do a test of KH before and after adding a few teaspoons and let us know

 

[guppygirl]

Ok, I looked at an old thread, and somebody posted this link...

:: What to do if my water lacks buffer (low KH)
If you choose to inject CO2 you really need to have a KH of at least 3 degrees. Starting with a lower amount of buffer means your pH is lower too. Since injecting CO2 to levels of 20-30 ppm requires a drop in pH of 0.6 to 1.0 it’s safest to do so with a starting pH of at least 7.4 so that at 30 ppm your pH is no lower than 6.4. Experienced fishkeepers can operate safely at levels below this if they have special circumstances but for most the prudent thing to do is to begin CO2 injection with 3 degrees or more of KH. To increase KH you can use baking soda. Baking soda is sodium bicarbonate. Bicarbonate/baking soda will raise the KH of 50 liters by 1 degree per 1/4 teaspoon. Baking soda will only raise the KH, if your water is too soft you may wish to use calcium carbonate to raise both GH and KH. Calcium carbonate will raise both KH and GH of 50 liters of water by 1 degree per 1/2 teaspoon. Alternately you can place crushed coral, cuttlebone or dolomite in your filter to dissolve slowly and increase both KH and GH but understand that this method is inexact and inaccurate.


This clear things up a little?

 

[guppygirl]

This would also mean that for about 50 gallons, I would use one teaspoon to raise the KH 4 degrees, like iggy said.

 

[Yenko]

ps. you can add a few tblspoons of baking soda to help raise the KH so to prevent a drastic change in pH.

Ok, I think I'll do that. How much do I add?

Raising your KH will increase the pH, but it does not magically stabilize your pH levels; the levels will still fluctuate just as much.

 

[guppygirl]

Raising your KH will increase the pH, but it does not magically stabilize your pH levels; the levels will still fluctuate just as much.

Yes, I know, but I don't want my ph to go from 6.5 to 5.5 or below!!! I would rather it go from 7.5 to 6.5.