Ph Drop

[stefday]

Hi,

I am very new to marine tanks so any help would be appreciated.

The Ph seems to keep droping from around 8 to 7.8 and then staying at this level. I have tried water changes and various buffers but it still seems to drop. Is it best to keep putting buffers in or is there somethinh else I should be doing?

 

[BigC]

How long has this tank been set up
Regards

 

[stefday]

How long has this tank been set up
Regards

About 3 months.

 

[seffieuk]

have you got very good surface aggitation?

Seffie x

 

[stefday]

have you got very good surface aggitation?

Seffie x

Yes. I have an additional pump which seems to be increasing the flow.

 

[xxBarneyxx]

What brand of salt are you using. When I used instant Ocean my PH rarely went over 7.8, never had any problems but I was only keeping a few soft corals.

Double check the rest of the water parameters as well and maybe switch to a different brand of salt.

Edit: One thing I forgot, I personally would say that as long as it is stable at that PH dont worry too much about it. A low PH will do less damage then one that is constantly bouncing up and down a lot while you try to adjust it.

 

[degsod]

Hi,

I am very new to marine tanks so any help would be appreciated.

The Ph seems to keep droping from around 8 to 7.8 and then staying at this level. I have tried water changes and various buffers but it still seems to drop. Is it best to keep putting buffers in or is there somethinh else I should be doing?

Is dropping 0.2 pH unit really a problem? It seems a very small change to me.

 

[xxBarneyxx]

The problem with the way PH is measured is that its on a logarithmic scale. So imagining the PH was measured in something like parts per million the difference between 7.8 and 8 would not just be 0.2 but could be 500 or 600 times different.

I cant remember the exact way its measured but basically 0.1 can mean a big difference in the PH.

 

[degsod]

I know that in freshwater the pH can change from say 7.5 to just over 6 with no adverse effects on the fish, and the are articles and links posted on here which basically say that pH is not really a problem, it is usually the hardness and other factors which are a problem.

In reality without expensive measuring equipment and taking into consideration temperature changes etc I wouldn't have thought that you could measure with any accuracy a change of 0.2

 

[xxBarneyxx]

That is very true of course, all hobby level test kits are difficult to read (at best) and not overly accurate even if you do read the colour spot on. However if you notice the difference in colour there has at least been some change.

PH is more important in SW then in FW for a few reasons (will let someone with more knowledge then me explain if they want) but like I said above I don't think it would be that much of an issue either to be honest. As long as it is fairly stable and your not keeping super sensitive sps corals or similar then 7.8 should be ok (My first 2 tanks where around the same PH and the soft corals and few LPS I kept did fine).

 

[degsod]

That is very true of course, all hobby level test kits are difficult to read (at best) and not overly accurate even if you do read the colour spot on. However if you notice the difference in colour there has at least been some change.

PH is more important in SW then in FW for a few reasons (will let someone with more knowledge then me explain if they want) but like I said above I don't think it would be that much of an issue either to be honest. As long as it is fairly stable and your not keeping super sensitive sps corals or similar then 7.8 should be ok (My first 2 tanks where around the same PH and the soft corals and few LPS I kept did fine).

I would like to know why/if it is more of a problem with Saltwater than fresh as some time in the future I will be crossing over to the salty side, so to be fore warned is to be fore armed so to speak !!

 

[xxBarneyxx]

There are a lot of reasons and I'm sure someone with more knowledge then me can probably add better information but from the top of my head here are a few reasons:

• Marine life (not just fish and large inverts but the microscopic life and things like 'pods) are not nearly as tolerant to water chemistry changes as most freshwater fish (even sensitive FW fish). The ocean has pretty stable water chemistry and unlike rivers and lakes it doesn't change very much even if there are heavy rains or flooding. As such marine life isnt adapted to changes in the environment in the same way FW life is (where a flood or large rain fall can change the PH rapidly).
• PH can effect the toxicity of of metals such as copper in marine life. As such a tank with trace levels of certain metals may be fine at one PH but if it then drops it can cause the metals to have lethal toxicity levels for the livestock.
• Corals and some other inverts require high PH for calcification. If the PH is too low it can stop corals growth and eventually can also kill them (effects LPS and SPS more than soft corals).

I'm sure there are many more reasons than that but in short marine life is not very tolerant to conditions outside of the natural seawater range (some life does better than others, a lot of fish would be fine but inverts and corals are effected a lot more).

Again though all of that being said I would say as long as your PH is stable at between 7.8 and 8.3 you should be fine.

 

[Trod]

I was very interested by this debate so done a few google searches I found these interesting, hope you do

http/saltwater-aquarium-guide.net/ph-and...twater-aquarium

http/saltaquarium.about.com/cs/phalkalinity/a/aa061301.htm

http/www.aquaticcommunity.com/marineaquarium/ph.php

After reading lots it seems the best way to stabilize PH is the good old water change.

 

[Trod]

Sorry but just found this a bit long winded but very interesting

http/www.advancedaquarist.com/issues/june2002/chem.htm

 

[degsod]

Sorry but just found this a bit long winded but very interesting

[URL="http/www.advancedaquarist.com/issues/june2002/chem.htm"]http/www.advancedaquarist.com/issues/june2002/chem.htm[/URL]

Very interesting, as one of the articals points out the measurement of the pH is one of the important factors, I think that people some times get 'hung up' on numbers, the simple fact of the matter is that the test kits available to the hobbyist should not be taken as gospel. You should only use them for basic trends.

You would probalby find that if you used 2 different test kits from the same manufactuer you would get 2 different answers. How the solutions are stored and handled will also have an effect on the end results. Even how you was the test tubes out will have an effect on the result.

Whilst it appears that with saltwater the pH range for keeping marine life sees to be quite narrow ie 7.8 to 8.3 it would appear to me that most of the kits being sold are not that accurate.

I have worked in chemistry in the past and have used the likes of pH meters and have been responsible for making the buffering solutions for calibrating the pH meters prior to use.

We used to use colour solutions similar to what we use as hobyists but these where only used as a guidline not as gospel. Also there is a problem matching a transparent solution with an opaque test card, ideally one would use a colorimeter to make the comparisons.

Anyway, I have learnt that the water parameters in the marine environment are a lot more crucial than I first thought.