Tank pH compared to Tap Water pH

[Byron]

@Byron I have just done another water test, and my pH and GH have increased back to what they originally was. I haven’t added the rock back in. and my test the other week proved that the sand wasn’t causing the pH and GH to rise.

Could there be something else causing this ? or do you think a water change every couple of days for a week could solve the problem ?

Thanks

I do not know if calcium or magnesium will penetrate objects like the substrate and leech out later. Perhaps another member will know.

Another possible is the source water may vary depending where it comes from.

 

[Alice B]

A certain amount of calcium coating will leach out later on tubing, tank, gravel. I don't know anything about sand beds and penetration, leaching though. I set up my first sand bottomed tanks in 2022

 

[Byron]

Just had another couple thoughts. One, the test...if this is the API test, the very first sign even if very faint of the green colour change is the number.

We should have the numbers too. The GH of the source water, and the GH of the tank water, to see how much of a change. Also, related, what is the pHdoing?

 

[PygmyMitch]

It is the API test kit that I am using for the pH and its a brand called NTLABs i’m using for the GH and KH. not sure if you can see the picture I put in of my test results. but my results are as followed:

20.02.23 Before water change
pH 7.4
GH 6

20.02.23 After water change
pH 7.2
GH 4

26.02.23 Before water change
pH 7.4
GH 6

26.02.23 After Water change
pH 7.2
GH 4

I will do a test of my tap water in a second and let you know what that is

 

[PygmyMitch]

@Byron My tap water results are:
pH is about 7.0 or 6.8. see attached photos.
GH is 2

bit of a difference in results compared to my tank water

 

[Byron]

There seems to be something in the tank raising the GH. It may just be residue still present.

 

[PygmyMitch]

I’ll do a daily water change for the next few days see if that makes any difference

 

[sharkweek178]

That is 42 by 39 by 38 cm. This is 62 liters or 16 US gallons. There is a conversion chart (Aquarium Calculator) on the right side of the page here.

Twelve pygmy cories, no change there. As I said, neons are OK, but if you want to have different, there are small tetras (Ember Tetra), the dwarf rasboras in Boraras, the Green Neon is smaller and does not have the health issues of the neon if you want to stay with this type of fish.

A word about the green neons. Only reason I know this is because I did some research on that one myself because I considered that species for my own tank. The Seriously Fish page for Paracheirodon simulans says they should be kept in pH of 3.0-6.5. That could be a problem considering the issues the OP is having with pH.

 

[PygmyMitch]

So an update on my tanks progress. 2 weeks ago I started another test, to try and narrow down the problem in my tank with pH and GH. So i have done 6 test samples, and recorded my results. Please see attached photos. The results are as followed that both the tap water and tank water alone have not changed any readings in 2 weeks time. The tap water with sand, and the tank water with sand have both had an increase of pH but the GH has stayed the same. Then finally the tap water with biomedia and the tank with biomedia have both had an increase of the pH and the GH.

So in conclusions the sand will definitely have residue from having the rock in the tank for so long. And the biomedia (which is relatively new in my tank, since I built my custom filter) this causes pH and GH to rise. I have removed this from the tank now. and should hopefully start to see my tanks pH and GH level out to the same as the tapwater.


Please see photo of the biomedia I had used. Its the fluval. Any recommendations for another biomedia I could try that wont cause th pH and GH to change. I have seen that there is 3D printed plastic biomedia. has anyone used them before ?


(Part 1 of 2)

 

[PygmyMitch]

Now as for my pH, GH and KH reading in my fish tank itself. I have kept track of every test I have done, before and after water changes (see attached results)

You can see that after a water change, the pH, GH and KH all decrease slightly. but then a week later they creep back up again. Then another water change decrease them again, till a week later. and so on….

However yesterday's water change has seen the biggest change in the water levels, to date. Its looking like my tanks water levels are almost back to what they should be from the tap. I will do another water test next friday and we will see if it increases again. Im assuming it will increase again as I have only just removed the biomedia after changing the water, so its very likely there is still some residue in the tank. Fingers crossed all the residue will be removed from the tank with another weekly water change or two.

(part 2 of 2)

 

[seangee]

I would be very surprised if it was the biomedia in itself. I have used the fluval stuff in the past. It may be, as has been suggested, that something has leached into the media but now that you have removed the source I would expect that to dissipate. FWIW I have plain old sponge in the filters of my 4 tanks. The benefits of specialist (and expensive) bio media is IMHO just marketing hype.

Now on to your readings. One of the reasons we change water regularly is to keep the water parameters stable. Your recent results suggest you have pretty much achieved that. You can ignore minor changes in pH - that fluctuates during the course of the day. Yes there is a slight drift in GH/KH but this is not significant and is countered by the water changes, also it is trending in the right direction. If you keep up with the 50% weekly changes I would expect your parameters to remain pretty stable. I am one of those who believes in large weekly changes, all my tanks get 70-80% a week. Some argue this is overkill but I have the assurance that my tanks start every week in exactly the same state. Two of these tanks are quite heavily stocked (some would say over stocked ) and all have enough plants that I never see nitrates. I only mention this because some people believe that removing nitrates is the only reason we change water.

With your naturally soft water there is another reason to keep up the water changes. Once you have successfully removed anything that adds hardness the low KH means that over time your tank will become more acidic. This in itself is not a problem for the fish, but if you need to do a large water change after a few months your fish could be significantly stressed by a sudden large change in pH.

 

[PygmyMitch]

yeah I was quite shocked that the sample of the water with biomedia gave the results it did. Now I did originally think the sample of water with biomedia wouldn’t change at all. But some of the biomedia i took out my tank a few weeks back (i did this to create more space for sponges) that had obviously dried up, you could feel they did kind of have a chalky like feel to them. So to me this did conclude that the biomedia reacted to the neutral to slightly acidic tap water. Giving the higher reading pH resuly agter 2 weeks.

Now you could be right in saying that, the biomedia has been in my tank previously where there has been residue off the rock. So could the biomedia also be leaching out the reaidue left from the rock. This could possibly be the case as well. Suppose I could change the water weekly in my biomedia sample and see if this is the case.

Yeah agreed my water perimeters might fluctuate slightly between water changes, but from removing the rock on the 12.02.23 and doing weekly water changes till yesterday 17.03.23, you can see the perimeters have decreased significantly, and they are starting to become more stable.

Yeah I think ai understand what you’re saying. So as long as I keep to the regular 50% water changes weekly and keep my water perimeters stable, I should have no problem and cause stress to the fish. But if I was to miss a week or two of water changes and then decide to do an even bigger water change than 50% this would cause stress and harm to the fish.

 

[Byron]

Sorry, I got the threads mixed up and posted my comments on another here. Now deleted.

 

[StevenF]

i looked through your profile and apparently you have at least one plant in your tank. When plant grow they extract nutrients from the water. this can change the water chemistry in your tank. In doing so the PH can move up or down depending on the chemistry of your water. Also when the lights are on the plants consume CO2 which can cause the ph to increase during the ay. So during lights on the PH will increase but with lights off the PH will drop.


If your tank continues to stabilize you don't need to do anything but if you have further issues you can try the following:


It is quite common for people to unintentionally test there PH at the same time during the day . check your ph in the morning before lights on and agin when just before lights off. Day sis stablo that for several day. if the PH after several days is at the if the daily up down swings are small you can ignore them. If they are large dim the lights.

If the PH drops every day add a sea shell to the tank the shell keep the PH close to 7. If the ph increases daily the tank is likely deficient in sulfur which plants need to grow. That can be corrected by adding a smal lamount of seachem equilibrium to ingrease gh by one degree should stabilize it.

 

[PygmyMitch]

i looked through your profile and apparently you have at least one plant in your tank. When plant grow they extract nutrients from the water. this can change the water chemistry in your tank. In doing so the PH can move up or down depending on the chemistry of your water. Also when the lights are on the plants consume CO2 which can cause the ph to increase during the ay. So during lights on the PH will increase but with lights off the PH will drop.


If your tank continues to stabilize you don't need to do anything but if you have further issues you can try the following:


It is quite common for people to unintentionally test there PH at the same time during the day . check your ph in the morning before lights on and agin when just before lights off. Day sis stablo that for several day. if the PH after several days is at the if the daily up down swings are small you can ignore them. If they are large dim the lights.

If the PH drops every day add a sea shell to the tank the shell keep the PH close to 7. If the ph increases daily the tank is likely deficient in sulfur which plants need to grow. That can be corrected by adding a smal lamount of seachem equilibrium to ingrease gh by one degree should stabilize it.

Yeah I have two plants in my tank. a Javs Fern and something else (not sure what its actually called)

I will keep regularly doing my weekly 50% water changes with a test of the water before, and after the water change. Hopefully I should see the water levels soon stabilise. Should they not, I will try the testing in a morning before lights on and testing on a night before lights off. Thanks for the tip!

Going off my tests and the pH levels or my tap water, my tank should return back to being 6.6 / 6.8. But If the pH levels drop below 6.6 I will add in a seashell. again thanks for the tip.

As for the pH increasing, I dont think this will be a problem for much longer after a few water changes. However, if I’m still having a problem in a couple of weeks time, with increasing pH levels I will purchase the seachem equilibrium.