Chemistry help: tap water, aging, hardness and PH changes

[Kall]

Greetings! I’ve been reading these forums for a while now, but since this is my first post I suppose a bit of background is in order. I “inherited” a 10g tank and all its accessories from a friend that was moving, and it was enough to get me hooked. I don’t like to go into anything uninformed, so I did some reading and spoke to several folks at various LFS’s in the area. I learned enough realize the importance (and even wonder) of the nitrogen cycle, and to replace the existing outdated UGF with an AquaClear Mini. Unfortunately it wasn’t until I started read sites like AC that I realized you can NEVER know enough about this hobby, and I could have done many things differently. (Not a single reference to fishless cycling in four books and over two dozen LFS folks until I went online!)

Anyway, the 10g is just finishing up its fishy cycle now (NH3/NH4+ is constant at 0 and Nitrites are around 0.25 and falling over last 48 hours. Nitrates seem steady at 20ish, PH is 7.4), so all is well I suppose. It’s stocked with 4 tiger barbs and 2 albino corys who seem healthy and happy, and I’ve done 25-30% water changes every other day since I started to help the fish stay less stressed thru the cycle. I’m planning to purchase a 72g bow front in the near future and have most of the accessories determined, but feel I have a great deal to learn still beforehand. Which leads me to my questions about water:

I actually started off using distilled water in the 10g since my tap water seemed unsuitable, and my LFS instructed me to stop that and use Aqua Clear and Perfect PH 7.0 instead for practicality reasons. I’m convinced now he was just trying to sell me product and have since read on these forums that distilled water is bad due to its ability to keep a stable PH. I’ve also switched to Ammo Lock instead of Aqua Clear since it supposedly binds NH3 into less toxic NH4+. (BTW: is there a difference between Ammo Lock and Ammo Lock 2? The active ingredients are the exact same on the bottle.)

I know a stable PH is better than constant fluctuations to get the “ideal” PH, but how high is too high. Straight out of the tap, my water looks like:

PH = 8.6-8.8, NH3 and NO2 = 0, NO3 = 5.0.

After “aging” the water 24 hours the PH changes to 7.8-8.0. I have no idea why. I plan to buy a GH/KH testing kit ASAP. (it wasn’t included with the master test kit I bought for some reason – at the time the LFS clerk told me hardness testing was “outdated”)

The really strange thing is that after I add the Ammo Lock to the aged water, the PH jumps up again to around 8.6, and then returns to 8.0 after another 12 hours. I also detected a slight NH3 reading of 0.25-0.5 or so, but I assume that is due to the breakdown of chloramines in the water into ammonia.

So my list of current questions:

1) How high of a PH is *too* high? I plan to buy a Python for water changes with the 72g tank. Is a PH of 8.8 acceptable?

2) Any idea why the PH changes as it ages, or after I add the Ammo Lock? Does it have something to do with the GH/KH, which I can’t measure atm? What exactly does the water hardness affect in terms of PH?

3) I have a household water softener in my house that all water except the two outside hoses is filtered through. What effect does that have on my water in terms of fish, PH and hardness? Do any of you have the same setup? Is it something I should try and bypass?

4) When doing water changes, especially in large tanks, how do you guys determine the temp. of your tap water? Do you use a 2nd thermometer or do you go by feel? (This is why I normally age the water, to get it to room temperature)


I have a million more questions, but I’ve probably bored you all to death already. Thanks in advance for your help and advice!

 

[tomm10]

First off, welcome! Next, congratulations on actually understocking your tank! I can never get myself to do that.

I get in over my head sometimes with chemistry but I believe the reason your water is changing pH as it ages has to do with it gassing off chlorine. I think this causes the pH to drop.

8.8 is a ridiculously high pH. 7.8-8.0 is still high but a lot of fish will do fine in it. You're not using that Perfect pH stuf still right? It won't help you.

RTR wrote a great article on water chemistry. It seems like i recommend it once week but since it really helped me I think its appropriate.RTR's Article This should give you a decent understanding of how the different aspects of water chemistry are related and dependent on each other.

Now to try to answer your questions:

1. I can't give you a number where pH is too high but I can say that for most fish, I think a pH higher than 8.0 is pushing it. Many fish will adapt to whatever surroundings they are in provided they are acclimated slowly but, personally, I would try to shoot for somewhere closer to 7.0. Provided you have a decent buffer, you can get there by adding some peat moss to your filter. Read RTR's article for a better idea of how that works.

2. The article will really answer this question better than I can. The short answer is that a water's hardness contributes to how high or low a water's pH can be and how easily it can be changed. In general, hard water has a high pH which does not alter easily and a softer water has a low pH which can be changed easily. That's a super simplistic answer but its the basic idea. Ammo Lock and/or aging of water is causing a chemical reaction that is altering the pH. RTR or happychem would be much better suited to give you the specific reasons.

3. Way out of my league on this one.

4. There are different schools of though on this one. Personally, I use warm water from the tap matched to the touch. Not real scientific but it works, especially when you're only doing a normal weekly change. Now, I can do this because the pipes and water heater in my house are fairly new and don't leech much if any metal into my tap water. in my last place I wasn't so lucky and needed to do water changes with cold tap water only. In that house I had to age my water. Some will argue that the water you're changing needs to match within a couple of degrees. Others will say it doesn't matter. I'm personally of the latter category. As long as you're not going to extremes or changing a large volume, I think its fine if you get it fairly close.

 

[Kall]

Thanks for the reply. The link to RTR's article was VERY helpful. It seemed to confirm my concerns that my household softener may not be good for my fish since it is exchanging the calcium and magnesium for sodium, increasing the TDS in the water. I dont know if thats something that can be bypassed (the only thing I can think of it to start its recharge cycle before I drain/refill the tanks since that forces a bypass automatically). Hopefully someone with firsthand experience can shed more light here.

Of course, it may not be worth worrying about. The common theme seems to be that stability and consistancy is better than modification in all cases. The owner of the one independently run non-chain LFS said that all stores in our area have to use the same water source I do, so the fish probably wont have a problem.

I've already thrown out the proper pH salts. What a waste. But - live and learn, thats why I'm here!

I planned on keeping around 25 fish in the 72 gallon, and almost exclusively members of the livebearer family: platys, swordtails, mollys, and fancy guppies, along with a few corys. From my reading, the livebearers apparently prefer a slightly basic pH of between 7.2-7.5, and I've crossed off most of the acidic fish like tetras. Of course, I need to figure out what the heck to do with the fry if they decided the pH is good eough to breed in!

About leaching metals: does Ammo Lock and/or Amquel products (or any other product for that matter) neturalize metals in the water as well as chlorine and chloramines? Many people praise their Python as a lifesaver in terms of time and convenience, but I never considered the problems of using heated water before. How do you guys solve this issue?