PH High Or Low Range

I get the exact same readings as you (top of the normal range, bottom of the high range)  so I interpret that just as you suggested that it's the average of the two readings ie 7.5.

 

My pH is the same too. As long as the tank water doesn't show a drop, I'm happy.
Anyone using something calcareous in the tank (eg coral sand, limestone rock etc) would need to check it wasn't going up too much, so with an 'overlap' pH they would also check with the high range tester.

Don't quote me on this but I may have heard or read that the liquid tests are more accurate in the middle 60-75% of their ranges... I will stand corrected if Sue or anyone else can testify otherwise.

But if this is the case then we're pretty much left to be happy with the fact that the pH is somewhere between top of the pH range and the bottom of the High pH range ie 7.5...

You are definitely wise to do the high range test. When you get a high pH (normal test) you can't afford to not know how high it is.

 

It depends on the individual tester, be they strips or liquid reagent testers. Some will be more accurate mid range, some at the lower end and some at the higher end. And no tester will be 100% accurate; they will have an error of around +/- 10%.

The best use of our kits is not the absolute value for pH but to regard it as ball park - is it neutral, slightly acidic, very basic etc. And to use the tester to catch any variations in pH. For example, those of us with very soft water need to make sure we do not suffer a pH crash.

pH meters will be more accurate. But as Richard W said in another thread

In any case a high degree of accuracy isn't required for an aquarium, fish all have a more or less broad range of tolerance to water parameters, which is what they would get in nature.

My pH sits in the overlap region of the two API testers. So I call my pH about 7.5.

Quote from: Skittler on May 03, 2016, 08:49:06 AM

I have very soft tap water, so I have to buffer the tanks with crushed coral in a bag in the filters.

What sort of a bag do you use for keeping the crushed coral in, Skittler? I have a chunk of limestone rock but am thinking some crushed coral in a bag in the filter might take up less space. I have a small bag that contained an item of jewellery and am wondering if it might do the job.

Cut the foot off an old pair of tights, fill it and tie a knot??

Hello All,

Well, it's OK for Paddy.........he presumably has a very local free supply of "tights". Me, I use a cut down muslin bag from the home brew section of the local hardware store. I just can't see myself stood there asking for a pair of tights ...... "Yes sir,...... and what size does Sir need?" After I bought a pack of "Silky, smooth knit anklets" from Amazon to cover the inlet on my shrimpery filter, they kept reminding me of my "recent purchases" ......... may God bless you Amazon, and may your parents soon get married!

Seriously though. the muslin bag has sat within the filter for over a year, and just gets a swish in old water when I change the top white filter pad in the Juwel. After the first addition of crushed coral, with only a small increase in KH &GH, I added some more which I beat to death with a mortar & pestel. From a starting point of KH & GH both 2, I now have a fairly steady KH4, GH6. If, as happens occasionally, large/frequent water changes cause a noticeable drop, then I add a small Aqualibra mineral block, which does contain a small amount of food, but also calcium and carbonates. It lasts about a week, and more than addresses the difference.

Hope this helps,

                                                     Skittler.........(barefoot!)

I didn't like to ask where Paddy got his tights from. 

It's his attire for cleaning the fishtank - this thread http://www.thinkfish.co.uk/forums/fish-tanks-and-equipment/best-bit-of-kit/msg22377/#msg22377 gave him the inspiration.

Skittler, thanks - that's all very helpful. The bag I was referring to that contained the item of jewellery is like muslin, so that might just do the trick. It sounds as though the KH and GH will rise in much the same way as mine does with the limestone but with the added benefit that it will create a little more space in the tank if I put the coral-containing bag within the filter. Thanks again!

What a man wears in his own home is his own business......isn't that right, Paddy. 

Yup!

(I'm giving nothing away here, you'll notice...)