slipitysmooth

Well...Long story, but I have had my 29 gallon tank running for about 6 months. My only issue has been high pH in the water, besides that all is well. My tap water comes out of the faucet at a 6.4-6.8, then I leave it sit with an airstone for 24-48 hours and get my true ph of around 7.6-7.8. My tank normally is in the 7.8 range, however recently it shot up to 8.6...I do weekly 25 percent changes and was living with the high pH, however I can't have it going that high because I'm sure to lose more fish (Lost one ram so far).

My questions are: What can be making the pH in my tank increase to those amounts? I've tested everything in the tank I can think of...the gravel, both display rocks, all were fine with the vinegar test. I have some plants in there that aren't doing much. Shouldn't pH go down with time? I was under the impression that waste matter as well as algae/plant decay will all lower pH. When my pH shot up I had an extra filter running on the tank for a 20L I am starting. Can that extra aeration cause the pH to spike that high? Did it super saturate the water with oxygen hence removing CO2 and raising the pH?

Thanks for any help...

Shawnie

welcome to fishlore!!
can you get a pic of the rocks? the vinegar test isnt always as reliable ...do you know if the rocks have any limestone or coral based at all? im no rock expert but just some suggestions....I hope some other members have more help! good luck!

aquarist48

Hello. From what I understand CO2 can lower your pH. Since you removed the CO2 that is a possibility it raised your levels. Here is a link you may find helpful. Too, I'm sure you'll get some more responses.
Ken
Properly Maintaining the pH in a Freshwater Aquarium - Rate My Fish Tank

bolivianbaby

Welcome to Fishlore

Unfortunately, I'm no expert on the "chemical" aspects of rocks. I'm sure another member will be along soon that can help you out.

slipitysmooth

I can get pics sometime...the rocks are a slate and a lava rock all from a LFS.

sirdarksol

The rocks are the primary culprit. A picture might help identify the rock.

Aeration doesn't remove CO2, it balances gas levels in the water to be equivalent to those in the air around the pump. Therefore, if the CO2 in the air is .5% and the 02 is 20%, then aeration will maintain the dissolved gas levels at the same ratio. So aeration likely is not the cause.
Edit: What kind of gravel do you have?
Also, what additives are you using?

slipitysmooth

I have petco branded gravel, fiji "color".

Shawnie

we were asking more for the rocks that are big and used as decorations not the subtrate...like the lava rocks and such ...a pic would help allot as well as that link mentioned above will give you more information

slipitysmooth

Here is the lava rock...



Here is the slate...



And this is my substrate...

Shawnie

hmm the rocks dont look like theywould effect it..but wait for another member who knows more about rocks...as far as the subtrate, do you know what it means by "aides in beneficial bacteria"? does it mean somethings added to it to aide in that process or just helps as they bacteria grows and sticks to it surface?

slipitysmooth

I'm not sure on that either, but I understood it as a marketing ploy, just as all gravel would "aide" in beneficial bacteria because it gives it somewhere to live and thrive...

Shawnie

so nothing added to it per say then like chemically?

sirdarksol

I agree. All three look to be neutral (though appearance can be deceiving).

What are you using to treat the water? Presumably some type of dechlorinator. What brand for that? Anything else?

slipitysmooth

I'm using prime to treat the water...I've been using RO to try and help cut down the pH, going with a 2 parts RO to 1 part tap to try and lower the pH. No other chemicals are being added, yet the pH creeps up to unsafe levels within a few days...

As far as the substrate, I looked on the petco site and all of their gravel says "aides in propagation of beneficial bacteria"...sounds like a marketing ploy to me.

sirdarksol

Okay, there shouldn't be problems with any of that.
Next questions:
What's in the filter? Simple floss? AC? Mixed AC/ammonia-absorbing-resin?
What kind of food are you feeding them? (can't imagine this affecting things much, but you've already ruled out most of the common causes).
At this point, you may want to try taking out one of the rocks for a week or two and seeing if that changes the pH shift at all.

Do you know what the hardness/buffer level of your tap water is like? RO water lacks a buffer, which, in turn, means that RO water can shift in pH very quickly. It usually shifts down, but it could go up quickly, if something basic was added.

slipitysmooth

My carbonate hardness was around 5 to 6 at it highest and is around 3 or 4 after using ro mixes...

In the filter is the marineland filters, floss with AC inside. I'm feeding new life spectrum flake and sinking pellets, with occasional frozen food...bloodworms and brine shrimp.

I was thinking about taking one rock out at a time, if I have to, definately hope it is not the slate because I plan on using it in my Krib tank I just set up...

slipitysmooth

well...i'm still unsolved.
I took the lava rock out and put it in my 10g quaritine, have shown no noticeable gain in pH in the few days its been in. Also, I took a bunch of gravel out and put it in a bucket of aerating water I have and have shown not noticeable increase in pH. Could it just be the water? I started a bucket and it was at 6.8...24 hours later it was at 7.6 or so then added 2 gallons of RO to 1 gallon tap and it was at 7.2, 5 days later it is back to 7.8 with just aeration...and there's a lid on the bucket limiting evaporation...

I'm stumped..my local fish guru is stumped...3 or 4 of his customers who have been in the hobby for 20+ years are stumped...

any help? If not help, what are some options I can take? Get tap from somewhere else? Get RO and add something to it for every water change? I know a perfect pH is not what I'm after, more stability...but I don't have stability with my tank as it is...the carbonate hardness creeps up constantly as does the pH...even within a week when I was doing normal weekly water changes it will jump almost a full number on pH.

dvc_r

I do 50% water changes three times a week in my 75 gal Discus tank. My tap water is 8.2 and my RO unit comes out about 6.4. So I use 36 gals of RO water with only 2 gals of tap. My tank is "stable" at about 6.8 (it fluctuates a little AM & PM because I have a DIY CO2 bottle). IMO: With the hardness at 5-6, your 2 to 1 RO/tap water ratio might be a little too high.

That's all I can see since everything else look alright.

One more thing: You said you did a vinegar test on the large rocks. That may not be accurate, try the same test with bottle #1 from the nitrate test kit- see if you get any "fizzing".

Otherwise you got me stumped too!

slipitysmooth

with the nitrate test bottle on the rocks, will the rocks be safe to use in the aquarium afterwards...?

dvc_r

Bottle #1 is 41% hydrochloric acid, so after testing my rock I thoroughly washed the rock and put it in my tank with no problems. But if you need any technical data I'm sure there is a chemist somewhere on this site that can help (Maybe one of the monitors know someone).