Terminology Debate

[colesea]

Okay, this really peeved me off a bit.

At work, I have one 30 gallon long tank. Since the store opened it has been home to an assortment of medium sized SA cichlids. It's on a 200 gallon system that has six ten gallon tanks, a 75 gallon waterfall tank, and a 30 gallon long wet/dry teterrium. You folk have probably seen the set up in a local Petco/Petsmart near you. Also on the system are our tropical plants, turtles, dwarf frogs, crayfish, and other SA cichlids.

Anyway, I'm bored with SA cichlids always being on that side, and the African Cichlids always being on the other system, in six ten gallon tanks of only two species each. Also on the African system (200 gallon) are six tanks of gourmis, and six tanks of odd assorted fish such as African knives, dojo loaches, angels, blood parrots, severums, rams, and oscars.  

So, I suggested that instead of having the SA cichlids in the 30 long, I could move all the African's over there, throw in some dolomite gravel, some quartz rocks from the beach, and make a little biotype out of it, moving the SA's to the African's previous tanks. My manager shot the idea down because he claims if I put all the Africans on this system, we would have to turn the entire system into a "brackish" water system, and thus loose all the plants, turtles, frogs and such.

Did I miss something? When did African cichlids become brackish water fish? I said, "okay, nix the dolomite gravel" he told me we would still have to turn the entire system "brackish."  I don't have the African cichlids in any form of "brackish" water now, so why would changing their tank suddenly turn them into a "brackish" water fish?  

I understand that African cichlids are a "hard water" fish, requirering high GH and kH, but when people tell me "brackish" I think of adding marine salt to increase salinity, not increase hardness. I know you can increase water hardness without increasing salinity, so why would I have to make an entire 200 gallon system "brackish" to house 30 gallons of African cichlids? Quartz rocks are non-carbonate based rock, totally scrubbed and soak, so they should not leach minerals at all into the water (in fact, aquarium gravel is quartz, duh!) to harm any of the other critters on the system. The water in the two systems is exactly identical, comes from the same source, and I don't treat any tank any more special than the other for the fish. In fact, the system the African's are currently on have an entire wall of tufa rock that doesn't seem to hurt the angles and rams on the other side of them at all.

Am I totally clueless...or is my manager just making up an excuse not to go through with the project?
~~Colesea

 

[dattack]

Most of the local fish store can place African cichlids in hard water without the salinity and the fish will do fine.  That's because there are some breeders that breed them under these conditions therefore the cichlids are adjusted to low salinity.

Furthermore, different lakes in African have different alkalinity and salt readings depending on the source of water.

Remember that salts doesn't necessarily just mean sodium but many other different compounds that attribute to the high alkalinity and pH.  

http://www.malawicichlidhomepage.com/aquainfo/salts.html

http://malawicichlids.com/mw01011.htm

So you are right essentially if you can raise the alkalinity by adding salts of varying proportions.

 

[dattack]

Oh yeah and they sell african cichlid salts and buffer.  I still feel this is only essential if you have soft water.  But if you have hard and alkaline water coming out of your tap, the africans can just do fine.

People add instant ocean but the African lakes don't contain that much sodium like the ocean.  In fact, it contains all the compounds and different salts listed in the link.

 

[colesea]

The water off our taps is hard, with a pH already of about 7.8. The pH in the marine systems is upwards of 8.4, and I know that is because of the increased mineral content from disolved carbonate rock and dolomite grave. I've test the water in the tufa rock tanks before, and usually it's pH of about 7.8. I've not ever really bothered to test the hardness levels because our tap water is already hard, and adjusting the pH of it is a pain in the arse.

I understand the relations between alkalinity and pH, and the various environmental conditions in Africa. I was just curious where my manager was getting brackish from. Maybe he assumed I was going to specially treat the water for this tank and thus affect the entire system.  I thought I was going crazy for a moment. I know people mistake the African's for "saltwater" fish all the time, but I thought I'd been doing something wrong.

Thanks for the links, info, and helping me learn.

 

[Somonas]

Africans are not brackish.   They are freshwater.

KH 12, GH 15, PH 8.2 is the chemistry of lake malawi if I remember correctly.  Tanganyka is around PH 9.2.  I do not know the salinity of the lakes.

Some aquarists add salt to their tanks (I don't).   at 1 tablespoons per 10 gallons

but in answer to your original question    Africans are freshwater.

 

[wayne]

Agree with somonas - africans are fresh water.  Hard water yes, with lots of dissolved salts, but still pretty much fresh water.
 Brackish water is the water formed where sea water and fresh water mix, such as river deltas, estuarys, tidal river plains.  Salinity in these rivers is super variable, but the vast majority of the dissolved salts in this stuff are sodium chloride NaCl, and (lesser magnesium chloride MgCl I think).  If pure water has an SG of 1 and sea water has one of 1.025, this would vary between these limits.  Rift lake water would be 1.001 I would guess.
 The water in the african lakes is pretty hard, with a higher proportion of calcium hardness, but you could still drink it - the amount of dissolved material is still much lower than in sea or most brckish water.  You will be sick if you drink sea water or brackish water - that's how different from hard water it is because of all the dissolved nacl.  The water from Malawi or Tang isn't so different from hard tap water anywhere in the world despite the strange geochemistry of the african rift system. Some people just add a very little sea salt and if you live in a soft water area that's close enough to help.  It probably doesn't matter for 99% of fish.
 Is this clear enough an explanation - I won't go on unless you want more.  
 I'm interested you keep the africans on the same 200 gal system as angels and rams - how hard is the water - rams are real fussy about that, and high hardness makes them a bit fragile.  Angels are a bit tougher, especially as they're so remote from wild stock now.
 You can make your own decision on your manager