There are many myths about pH that abound in today’s society. From what’s best for a certain species, how to change it, how to keep it stable etc… With this, I aim to debunk and demystify some of the more popular myths about pH to help those new to Rift Lake cichlids have a better understanding. And who knows, maybe even teach some of the older dogs some new tricks on the process. Believe me, you don’t have to be a chemistry whiz to be able to figure this stuff out.
While this article is written more to the tune of Lake Tanganyika, one of the Rift Lakes in Africa, I hope that even for those not interested in the Rift Lakes, that they will be able to take away a better understanding of what pH is and how it affects our fish.
As we all have been, I was a newbie once. Standing in awe at the LFS looking in wonder at all the products available to me. Thinking “Wow, fish keeping can’t be that hard, just look at all the nice, overly priced chemicals that the wonderful company’s have made just for me.” Well, guess what. There are more products on the market today intended to part an inexperienced aquarist with their money that those that are useful. Aquarium companies exist to make money. Your Local Fish Store (LFS) is there to make money. Do you really think that they can survive on the sale of $.99 danios alone? Nope. That’s why they make, and often sell some very useless products. The water where you live has a natural pH, and any attempt to alter it is an effort in futility without being armed with the proper knowledge and know-how.
Lake Tanganyika
Yeah, I’m a little bias to this lake of all the rift lakes in Africa. This is where I find that the most amazing fish live. Lake Tanganyika has some of the most widely diversified cichlids found anywhere on Earth. While this lake is not the only place in Africa, or even Earth, you will find fish from this family, the species here have been isolated for millions of years and have evolved to take over the lake, and remains its rulers. The pH of the lake has been recorded above 9.5. Most of the Lake also has very hard water, with General Harness (GH) in the high twenty’s, and Carbonate Hardness (KH) in the high teens/low twenty’s depending on the location of the water sample tested.
I have kept cichlids from Lake Tanganyika for some time now. At first I was more than happy to do my part to replicate the natural water conditions from which the fish came from. Then I became lazy, and thought that it wasn’t necessary to do this, that my fish look fine, seem healthy and are breeding. Remember, surviving isn’t always thriving. Keeping your pH high for Rift Lake cichlids is, in this authors opinion very important, and luckily isn’t a difficult task to do, but it does take great patience, and a willing mind to do it properly. It is certainly not for those ‘Lazy’ hobbyists among us.
But before we go much further, we need to learn exactly what all these numbers, strange abbreviations, and test kits mean. Why are they important to us, but more importantly, why are they important to our fish.
What is pH?
PH is the measurement of the acidity and alkalinity of a substance. For the purpose of this article, we will stick to the pH of water. The pH scale goes from 0-14. 0 is very strong acids, where 14 is absolute alkalinity, and 7 being neutral. The pH scale is what’s called a logarithmic scale. Meaning that each whole increment is 10 times more, or less than the next or previous unit. So a pH of 8.0 is 10 times more alkaline than a pH of 7.0. And a pH of 6.5 is 5 times more acidic than 7.0. Here we can see why acclimating a fish to a new pH slowly is so important.
KH and GH
What does these numbers have to do with pH? A lot! This is the measurement of the hardness of the water. Hardness is the measurement of the degree of dissolved minerals found in water. The more dissolved minerals, the harder the water. The less, the softer the water.
Unlike the pH scale, which is universal, hardness can be measured in two ways. Degrees (dH), or parts per million (PPM). These are the most common ways to express hardness, with measurements in degrees being most common and widely used among aquarist. This table gives a brief look at what is considered ‘Soft’ water and ‘Hard’ water.
The kH of an aquarium can often times be related back to the pH of the water. The higher the kH, the higher the pH. But please keep in mind, that this is not always the case. The kH is actually the measurement of the waters alkalinity. This alkalinity measurement can tell you about the water’s buffering capacity. The higher the kH, the more able the water is able to withstand addition of acid compounds into the water, keeping the pH stable. In soft water you are less likely to find such a buffer, and the pH can change much easier, for the good or for the bad.
Now don’t look at this as any soft water tank is doomed for failure if the owner tried to keep rift lake fish because it is not. This is very far from the truth. All this tells you is that if you have soft water, you are going to have to pay extra attention to water changes and what goes into the aquarium. Putting the extra time and effort into your tank can often give you an even greater sense of accomplishment once done. Driftwood for example is a very popular decoration for aquariums, but it does have to ability to alter the pH. It does this because driftwood can release tannin into the water. This tannin is acid based and can lower the pH of an aquarium, though most of the time not enough to worry about. This is why most Rift Lake set-ups are seen without real driftwood. (The effects of driftwood on pH is highly dependant on the natural KH of the water.) Other decorations not labeled for aquarium use can also release minerals or even toxins into your water, again altering the chemistry. Unless you know for sure that something is safe or not for aquarium use, its best to just not use it at all.
Planted tanks are becoming more popular in the aquarium hobby for many reasons. And the most common fish one is likely to see in these types of tanks are species of fish that come from South and Central America. Why? Because some planted tanks require additional nutrients and gases to grow to their full potential. Co2 (Carbon dioxide) is often injected into a planted tank. Co2 will create a chemical reaction once in the water that will reduce the pH. The water volume and amount of Co2 being injected determine the reduction in the pH. This is a big reason of why you will not normally see many hard water species living in planted tanks with Co2 injection. If you like planted tanks, and like Rift Lake cichlids and would like to mix the two, don’t worry. All is not lost.
A lot of commonly found aquarium plants do best in soft, acidic water. However there are some that actually do better in the hard alkaline water that rift lake cichlids thrive in. And Co2 injection is an option, not a necessity, with a planted tank. Some species of crypts, vallis and anubias to name a few can do quite well in a hard water tank with no additional Co2 injection. But I’m not going to get into the how-tos of planted tanks. I’ll leave that for another author.
Before you try any plants in your Rift Lake tank, you need to research the plants just as you would research your fish. Make sure that you can provide them with their basic needs, and they will reward you for years to come. Also it’s generally not a good idea to keep plants in the same tank as any herbivorous species. Before you know it your nice beautiful bed of Vallis can be ate to the ground by a hungry group of Tropheus. Many things need to be taken into account to keep a happy, well-balanced tank.