The pH in my tank is decreasing notably from day to day.

I test when lights are on...
I am only dosing reef code a/b twice a week, microbacter once a week (in the order of a few drops), iodide and that's it.

I can't for the life of me understand why my pH is so low.

Any suggestions/ideas? I want to keep this from crashing

Whats your alkalinity/dkh? That keeps your PH in check.
I would dose some ph chemicals until you get it stabilized.

I don't know where you live, but if it's cold there and the house is all sealed up then you prolly have a buildup of CO2 in your house. CO2 is acidic enough that it is used to lower pH when needed....this is going to sound crazy, but openy our house all up for a little while and let it air out good then test again and see if it doesn't go back up to where it belongs....

What is your pH currently, and what value has it decreased from?

It's around 7.0 and it decreased from 7.8

I can't afford fancy testing equipment, but I do have the same strips they use at my LFS. I don't mean to skimp, but jobs are .. kinda hard to come by lately, so money has to be saved where it can be.
I test daily, and have noticed that the pH pad on the test strip has gone from its brightest 7.8 color to a much duller pink indicating around 7.0


I haven't altered my water chemistry or added anything too crazy to my tank other than a small candy cane frag. Maybe my lights are too old? they are power compact (it's a BC 14)

+1 this happened to my tank last winter!! Especially if you are heating your home with natural gas.

I have an excess of PH buffer if you want me to send you some. If you want it you can have it for free.. shoot me a PM and I will hook you up.

It could be many things but using a buffer will help stabalize things so you don't have loss....

has anything in the tank died recently?

don't use a ph buffer, that stuff is snake oil. it's nothing more than a temporary "fix" that will do more harm than good.

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

The real problem is that you have inaccurate testing methods. A pH of 7 is nearly impossible for saltwater. Test strips are very bad. The API saltwater master kit (has ammonia, nitrite, nitrate, and pH) is a much better alternative and inexpensive if you buy online.

Bottom line: this is not an emergency because you really don't know what the tank pH is in the first place.

buffer is a great way to raise pH, one cannot deny it. It is temporary though, especially when alkalinity is low. Test your alkalinity. The lower the ALK, the higher the chance of the pH to swing low.

Do you have any tank inhabitants? How are they responding?

+1

The local Petsmart should have a better pH test for a reasonable price. It would really suck to fix a problem that wasn't really a problem in the 1st place. Then all of a sudden your problem isn't too low of pH but too high a pH.

this

There are some basic supplies that have to be purchased to keep a tank alive. Budgeting that amount of money will keep your other investment ie: the tank alive.

This is correct, but CO2 itself is not acidic. It reacts with water to form a weak Carbonic Acid H2C03 (CO2 + H2O ⇌ H2CO3) which is what lowers the pH A tight fitting hood can also cause this problem since it limits gas exchange within the tank.

I had a problem with gas exchange once (no pun attended). I bought a small air pump and used that for about two days. Issue resolved.

I love your replys.Always to the point and dead on