Liquid Tests Vs Test Strips

I know it's generally advised to use liquid tests because the strips tests are thought to be inaccurate. Does anyone know why? Has anyone experimented with both?

I'm just curious where the opinion comes from.

Yes, I've experimented / am experimenting with both - see http://www.thinkfish.co.uk/forums/index.php/topic,2151.0.html.  [ I've been enjoying being surrounded by increasing numbers of test tubes in an effort to convince myself that I'm more skilled in traditional sciences than I actually am. ]

My findings are as follows:
* test strips seem to provide very consistent results, both for a particular brand of test strip and between brands [JBL and Tetra]
* PH is the one test that shows the biggest difference between test strips and liquid-based test kits [strips 6.4; liquid 7.5 - both Waterlife and Aquality] - the higher PH is actually more similar to what the local water supply company states
* other tests (nitrates, nitrites) are similar/same between test strips and liquid-based kits (JBL, Waterlife) but I do have very low nitrates whereas those with higher nitrates might find a difference
* GH and KH are fairly similar between test strips and liquid-based kits but water never quite matched any of the colours on the strips, hence buying test kit to be sure

Some folk report that API nitrate liquid kit needs vigorous shaking in order to get an accurate result.

Hope that helps.

Thank you both for your replies. I'll need to get a new testing kit in a couple of months so this got me thinking about what's best for my tanks.

I find your findings very interesting, fcmf, seems the accuracy varies from test to test.

I think the right question to ask is: "is it fit for purpose?" So, in case of pH, the difference between 6.4 and 7.5 may be quite significant (depending on the circumstances). With ammonia, unless you're cycling, you basically need to know if you need to grab a bucket and start changing the water.

I do agree that new tanks have to be tested for ammonia, especially whilst cycling. If I decide to buy ammonia strips, I'll test them against my liquid test.

I did a bit of research, particularly about ammonia testing and apart from the liquid and paper tests I found this: http://www.seachem.com/Products/product_pages/AmmoniaAlert.html

It seems to be a similar kind of indicator that seneye are using in their slides. Has anyone used the Ammonia Alert?