AboutJennifer Schanely Expertise I have worked for sixteen years in a pet store where I am the fishroom manager. I can answer most questions pertaining to saltwater fish and coral care, feeding and behavior. I am knowledgeable in setting up and maintaining reef and fish only tanks and can usually identify creatures that come off of live rock. I am only slightly knowledgeable on disease treatment with prevention being my specialty. My approach to the marine tank is that of simplicity. Keeping a marine environment is easy and I encourage anyone intersted in this hobby to give it a try!
Experience Besides owning various types of tanks,I have worked as a fishroom manager in a pet store for the past sixteen years. I answer questions to many fish related problems on a daily basis. At our store we have many fresh water tanks, salt fish tanks, corals, and other invertabrates. I also know alot about different products on the market and what works and what doesn't.
Education/Credentials I think sixteen years experience is far more education than any school could have taught me.
Expert: Jennifer Schanely Date: 7/20/2008 Subject: salt water aquarium Ph levels
Question The last few times I have done a water change the ph has dropped from 8.3 to 7.5 which has killed my fish. I use distilled water and add prime conditioner along with the salt. If I add too much salt could that have a chemical reaction to change the ph? I change only 4 gallons at a time during water changes. I have checked the ph in the tank before hand and its good and the ph in the new water is good. My amonia, nitrite and nitrate levels are good. I'm confused on what could be happening.
Answer Hi Howard. There can be a few different reasons for a decline in pH in your tank. You say you are only changing four gallons of water at a time. What size is your tank and how often are you changing the water? These are going to be very important factors in determining exactly why this is happening to your pH. Seawater has a considerable natural buffering capacity, that is the ability to absorb excess H+(positively charged)ions without lowering the pH. Positively charged hydrogen ions are what causes your pH to become lower. The biological activity of the filter and the animals, however, eventually overcomes this built in buffer and the pH begins to drop. The decline is quickened by overcrowding, lots of detritus build up, lack of calcareous material with exposed surfaces(reef rock, coral sand substrate, live rock etc.), and build up of dissolved organics(due to lack of protein skimmer). Doing more frequent partial water changes may be needed to dilute the build up of dissolved organic wastes and restore natural seawater buffers. Baking soda is frequently used to push up the pH when water changes are not possible but eventually it will drop again. You can use this when your pH starts to get low by dissolving one teaspoon of baking soda(sodium bicarbonate) per 20 gallons of water in a small cup of your tanks water and then slowly pouring it into your tank. Wait for it to thoroughly mix with your tanks water and test your pH to see where you are at. Do this repeatedly until you have reached the proper pH. This should only be done if you can't get to doing a partial water change as it is not a permanent fix.
Then there is the accumulation of CO2 that could be giving you these problems. When CO2 builds up in the water excess carbonic acid is formed and pH drops. In many systems, especially those with extensive biological filtration and little aeration(such as undergravel filter set ups)the build up of CO2 is great enough to keep the pH at uncomfortably low levels. Addition of a trickle or wet/dry filter or any large increase of internal tank aeration will help vent excess CO2. Make sure if your tank has a lid on it that there is some part of it that is open in order to have a good exchange of gases at the waters surface. To check if this may be the problem take some of your water out of your tank and place in a cup or bowl. Check the pH. Aerate this water for an hour or two and recheck the pH, if it has risen a point or two during aeration, the system is accumulating CO2 and you need more aeration.
