Low pH

[westward13]

Ok. It's been several weeks since I've last tested my water parameters and I was surprised to find my pH at 6 (or below). I don't have anything to test the alkalinity of the water at the moment but I'm curious as to how I should attempt to add baking soda to help raise the pH (or if I should hold off altogether until I can test the alkalinity as well). I do 25-35% water changes every 7-14 days and feed the fish twice a day (but not in excess). My ammonia and nitrites are 0 but my nitrates are also somewhat high (40-80 range but I can't tell with the test kit card). I'm going to try to do more frequent water changes over the next few weeks but was wondering what else I can do at the moment. I read a few older posts where crushed coral and baking soda was mentioned so I may give one or both a try. Any additional recommendations and/or potential causes to the severe drop (it was at a pH of 7.2 for a very long time with little to no change).

 

[deeni0z]

What's the pH of your tap water? If you don't use tap water, what's the pH of your source of water?

 

[westward13]

My tapwater's pH is 7.2

 

[TankGirl]

Next step will definitely be to test your KH and GH. pH stability is dependent on KH, so that is really an important number to know whenever you are concerned about pH. Test tap water and tank water and post back before you do anything with baking soda.

Crushed coral in the filter is a very benign way to buffer your water, so I would try that first.

Is this an old tank? With your tap water at a higher pH than your tank, more frequent, regular water changes are going to likely get you where you want to be, and with no more information to go on I would assume you have a mature tank with a fair amount of detritus and whatnot on the bottom creating an acidic environment. Very gradual increases in maintenance, with care not to do anything drastic, will reverse the situation.

If it is a new tank then we'll have to point our brains in a different direction, lol!

 

[krap101]

hmm how would the ph be going down in the tank unless theres peat/wood in it?? because ive seen ph go up but how would it go down? 8O

 

[westward13]

I tested the alkalinity and hardness of the water tonight and it came out as 40 KH and 150 GH(hard). That said, how does that tie in to my pH of 6 or below? I also bought a bottle of pH up in an attempt to try to slowly raise the pH (along with doing more frequent water changes). The store only had a huge bag of crushed coral which I didn't want to buy since I'd only need a relatively small amount but I'll try to check another store to see if they have a smaller bag.

 

[Menagerie]

Don't add the pH up just yet--your tank may yo-yo back and forth if the buffering capacity is no good. That's where kh and gh come into play, but I don't remember the rules.

 

[TankGirl]

All you need to raise your pH is to increase your water changes, using your higher pH tap water, but 40ppm of KH (if I understand your post correctly) is very low so I do think crushed coral is the ticket. I don't think you are going to find a smaller bag of crushed coral, and it will last you a long time, but it is the safest, simplest way to buffer your water.