Tap pH different from tank pH and Water Changes

[WaterBaby]

Thanks Bob,

To answer your questions:

Not using CO2 (although I would like to)

I use Flourish (according to directions) at every other water change

Flourite substrate, 2 river rocks (very solid, have had them in my other tanks before adding them to this one). One tall standing orange and white striped rock (don't know the name of this one, but it has been in my other tanks as well).

I did get this tank from someone. Don't know if it was repaired. Interesting thought. It's a black 29g with black silicone. It doesn't look to have been repaired. Although I've never seen a tank with black silicone before. :huh:

I hope nothing is leaching from the silicone (now you have me worried).....

I don't know the GH/KH on any of my tanks ( I don't have that/those test kits).

Filter is a Penguin 170 BioWheel. I cut my own filter medium. No carbon.

Does this help, and should I get the other test kits?


*and yes- it's the same tank. Cycled with Bio-Spira. I added most of the fish from my 20g and it did start out with a 7.2-4...... However, my 20g was not planted. I added the plants when I added the fish, and have been adding a plant here and there ever since. My other tanks are not planted, and the pH is higher in these tanks

 

[Rbishop]

Since you had the rocks in your other tanks, that should eliminate them; can't see flourish being the cause, though I am not much of a live plant expert by any means.

I have seen black aquarium sealant, but that has been years ago.

I would worry about a used tank from the perspective if someone used copper meds in that tank. Seems you would/could be having fish issues, and I am not sure how copper affects pH (time for a web search..LOL). I know copper can be very bad for many fish.

I think you can buy a copper test kit and check. Also, the GH/KH tests will help determine if your buffering levels are where they need to be for maintaining your pH. A plant guru might chime in and give insight here.

I'll do some searches for black sealant/silicone. I see numerous posts on here about repairing tanks, and the common thread seems to be where can I get it cheap and how do I know it is safe. They always get the dreaded answer, go to the hardware store, and that bothers me.

I've seen some mighty neat repair jobs on used tanks that are cheap...I bring them home and they usually leak from the wrong silicone.

Also, a used tank could have been used for reptiles which expands the possibilities.

Did not mean to make you worry....just shotgunning possibilities.

 

[Ulan]

Black silicone sealant is quite common in new glass tanks. The oak trim ones come often with matching sealant, too.

 

[Rbishop]

Yep, so I see now after looking. Since it is a used tank, I have some concerns on the correct sealant though.