Brackish And Scat Questions

[fryeguy82]

i will describe my tank before i begin to ask my questions it is a (US measurements) 55 gallon 48x12x21 tank. it has a pair of puffers, 4 mollies, 4 platys, 2 hoplo catfish, and 1 green scat (scatophagus argus argus i believe, spots with no stripes) before i had the puffers and scat i heard the mollies would thrive better with a little salt in the water, and research revealed that the other fish would be fine. i first added the puffers and the lfs told me to add 1 tablespoon of salt per every 5 gallons. he pointed me towards some aquarium salt. i had to remove some other tankmates later that i found out would not cope with salt in the water. i did 2 teaspoons every other day, because i didn't know if doing it all at once would shock the other fish. once the salt was in the puffers soon joined and have been happy since. a little later the lfs had some green scats for sale out of their brackish tank. i was told one would do well with the community i have. i bought him and a few days after he was introduced he began to develope some fungus so i went back to the lfs and i saw theirs had some too. i pointed theirs out and said mine looked look that and he said, "oh, wow i didn't even notice" so he told me to add an extra half tablespoon per 5 gallons. that did the trick, the fungus went away and his color became more brilliant. so here are some of my questions:

is this the correct type of salt? i've read some aquarium/marine salt debates and they just go in circles

is this the correct amount of salt?

is there a salinity test kit that can measure such low salinity levels?

my scat won't eat flakes. i've read they are heavily vegetarian and meaty foods should be occasional. i've tried 2 types of flakes, crushed algae discs and variety wafers and all he'll eat are the live black worms and frozen blood worms that the puffers eat (they don't eat flakes either, though, i hear that's common) are there any other vegetables or vegetable like foods i should try?

after my ignorance of only buying 1, i've read that they should be kept with 3 or more. what will happen if he stays the lone scat?

as he reaches adulthood he will require a bigger tank and more salt which will require a different tank. i figure six to eight inches would be about max for this tank. does anyone know how long it will take to reach this size?

i hope i've given enough background info, i know i sure have typed a lot. i know i've asked a lot but if people could answer any of my questions i'd be very greatful.

thank you for your time,
chris

 

[nmonks]

is this the correct type of salt? i've read some aquarium/marine salt debates and they just go in circles

Brackish water fish should be provided with marine aquarium salt. "Tonic salt" raises the salinity but does nothing for hardness and pH. So, look for something lile Reef Crystals, Instant Ocean, or whatever. Buy whichever is cheapest, and ideally in bigger tubs to save money in the long run. If you have a marine aquarium, you can usually re-use water from there in a brackish tank and just dilute with tap water as required.

is this the correct amount of salt?

No idea -- the "teaspoon" isn't a standard unit of measurement. Your selection of fish will work best at 20-25% seawater, which is about 6-9 grammes of salt per litre, or about 0.9-1.2 oz per US gallon. In specific gravity terms, that's 1.003-1.005. Hoplosternum littorale is a brackish water catfish in the wild but not a high salinity one, and 25% would be about the highest for long term health, and above 40% is known to be fatal.

is there a salinity test kit that can measure such low salinity levels?

Sure there is. A plain vanilla floating hydrometer (around $5) will do the job nicely.

my scat won't eat flakes. i've read they are heavily vegetarian and meaty foods should be occasional. i've tried 2 types of flakes, crushed algae discs and variety wafers and all he'll eat are the live black worms and frozen blood worms that the puffers eat (they don't eat flakes either, though, i hear that's common) are there any other vegetables or vegetable like foods i should try?

Hunger makes the best sauce. Scats will skip the salad if they think there's steak on the way. So will most other omnivorous fish in fact. So skip a meal or two, and then bring out the veggies. Scats enjoy cooked peas, spinach, blanched lettuce, sliced courgette, hair algae, duckweed, pretty much anything soft and green.

after my ignorance of only buying 1, i've read that they should be kept with 3 or more. what will happen if he stays the lone scat?

He'll be fine. In a 55 gallon tank you can certainly add another young scat without problems, but do bear in mind they can get quite big, and of the commonly traded species the smallest is about 15 cm when mature (Selenotoca multifasciata) and the larger ones at least 20 cm long (Scatophagus argus). Scats grow briskly, and expect full size within a couple of years.

Cheers, Neale

 

[fryeguy82]

wow, thank you very much, that's about as helpful as one can get. i appreciate it. sorry about the whole tablespoons thing, don't think i could convert table spoons into grams, so i'll be sure to pick up a test kit after work today with the marine salt. now the question is how will the test kit measure the aquarium salt. will it give the same reading as if i had marine salt in there? not knowing the answer to that i will still ask this: if the salt levels are correct or low, how would i go about using marine salt with aquarium salt in the tank? should i just begin to add the marine salt during water changes? or, if it's low can i use the marine salt to bring the level up? i don't know if my questions make sense as i am rather ignorant to the topic. i hate to bug you with all of these questions, but 'tis the price to pay when you have the answers

also, you said: "He'll be fine. In a 55 gallon tank you can certainly add another young scat without problems" are saying he'll be fine by himself or if i add another young scat? i'd like to keep just one if he'll be ok that way.

thank you so much again,
chris

 

[nmonks]

now the question is how will the test kit measure the aquarium salt. will it give the same reading as if i had marine salt in there?

You don't want a test kit. You want a hydrometer, a thing that measures the density (specific gravity, or SG) of water. Freshwater has a density of SG 1.000, marine water a density of SG 1.025, and brackish water something in between. You can (easily) measure salinity directly, so you use density instead, density being a proxy for salinity. The higher the salinity, the higher the densitiy. I have a little freeware program called BrackCalc that will help you understand the relationship between salinity, density, and temperature. A cheap glass hydrometer costs about $5, but you can spend much more than this on fancy plastic ones and even more on refractometers. While those may be better in some ways, for brackish water fish the cheap glass ones work fine.

not knowing the answer to that i will still ask this: if the salt levels are correct or low, how would i go about using marine salt with aquarium salt in the tank?

You add water at the new SG with each water change. Say the SG of the water in the tank is 1.002. If you do a water changes of 25% each week, adding water at SG 1.005, after a month or two the SG will gradually work its way up to 1.005. In doing so, the filter will gradually adapt to the elevated SG. Don't suddenly try to increase salinity. There's no point, and at worse you could kill off your filter bacteria (the fish couldn't care less).

also, you said: "He'll be fine. In a 55 gallon tank you can certainly add another young scat without problems" are saying he'll be fine by himself or if i add another young scat? i'd like to keep just one if he'll be ok that way.

He'll be fine on his own. He'll be fine with a friend. Scats are sweet-natured fish and don't bully one another, even though they can be a trifle pushy at feeding time.

Cheers, Neale

 

[fryeguy82]

thank you, i'll be sure to pick up a "hydrometer" today.