Keeping A Brackish Tank

paulypaul182

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Hi all, my tank is all cycled and Im considering my options for its stock. Ive seen quite a few fish that are brackish which I really like (mainly the BBG). How would I go about keeping a brackish tank. Apart from the salt, is there any other major differences to a freshwater non brackish tank? My tank is 100 litres and planted. It has a sand substrate with some fine gravel in there also.
 
You need to decide first whether you want a low-end system (around SG 1.003, up to SG 1.005) or a mid-salinity system (around SG 1.010). The first type is great for gobies, halfbeaks, glassfish, livebearers, killifish, chromides, figure-8 puffers, sleeper gobies and stuff like that. It's very flexible because you can also keep certain salt-tolerant freshwater animals like cichlids, nerites and cherry/amano shrimps. Mid-salinity systems appeal to those people who like migratory, estuarine fish that would, in the wild, be moving between fresh and salt water all their lives. These are things like scats, monos, shark catfish, big puffers, snappers, waspfish and so on. Plants aren't really practical in such tanks.

Give your interest in BBGs and plants, I'd go for a tank around SG 1.003, though set the thing up as freshwater or maybe SG 1.001 to let the plants establish themselves. They will tolerate brackish water much better if they are already settled in. Plants love sand, but it doesn't have much nutrients, so adding a bit of aquatic soil (pond soil) or laterite underneath, mixed with pea gravel, and then topped with sand makes all the difference.

Raising the salinity is easy. There's no "perfect" way to do this, but I'd recommend just doing water changes as per usual, but instead of adding freshwater, add SG 1.001 water (that's water with 3.5 g marine salt mix per litre). Keep doing this for a couple of months. By the end, the tank will be stable at SG 1.001. Over the next month or two, repeat doing SG 1.002 water changes (4.9 g/l), and then the same thing with SG 1.003 (6.2 g/l). This will gently adjust the plants and filter bacteria to brackish water.

Do have a look at my Brackish FAQ for more information, and try Brack Calc to understand how salinity works.

Cheers, Neale

Hi all, my tank is all cycled and Im considering my options for its stock. Ive seen quite a few fish that are brackish which I really like (mainly the BBG). How would I go about keeping a brackish tank. Apart from the salt, is there any other major differences to a freshwater non brackish tank? My tank is 100 litres and planted. It has a sand substrate with some fine gravel in there also.
 
You need to decide first whether you want a low-end system (around SG 1.003, up to SG 1.005) or a mid-salinity system (around SG 1.010). The first type is great for gobies, halfbeaks, glassfish, livebearers, killifish, chromides, figure-8 puffers, sleeper gobies and stuff like that. It's very flexible because you can also keep certain salt-tolerant freshwater animals like cichlids, nerites and cherry/amano shrimps. Mid-salinity systems appeal to those people who like migratory, estuarine fish that would, in the wild, be moving between fresh and salt water all their lives. These are things like scats, monos, shark catfish, big puffers, snappers, waspfish and so on. Plants aren't really practical in such tanks.

Give your interest in BBGs and plants, I'd go for a tank around SG 1.003, though set the thing up as freshwater or maybe SG 1.001 to let the plants establish themselves. They will tolerate brackish water much better if they are already settled in. Plants love sand, but it doesn't have much nutrients, so adding a bit of aquatic soil (pond soil) or laterite underneath, mixed with pea gravel, and then topped with sand makes all the difference.

Raising the salinity is easy. There's no "perfect" way to do this, but I'd recommend just doing water changes as per usual, but instead of adding freshwater, add SG 1.001 water (that's water with 3.5 g marine salt mix per litre). Keep doing this for a couple of months. By the end, the tank will be stable at SG 1.001. Over the next month or two, repeat doing SG 1.002 water changes (4.9 g/l), and then the same thing with SG 1.003 (6.2 g/l). This will gently adjust the plants and filter bacteria to brackish water.

Do have a look at my Brackish FAQ for more information, and try Brack Calc to understand how salinity works.

Cheers, Neale

Thanks again Neale. So I would have to get the salt stable before I add the fish? Ill check that FAQ now. Those fish you have mentioned have all been ones Ive been interested in but then found out I couldnt keep them in my freshwater tank. I have got plant substrate in there. I have a bottom layer of plant sub, then a layer of fine gravel and then a 1 to 2cm layer of aquarium sand.
 
So I would have to get the salt stable before I add the fish?
Nope. The fish couldn't care less. Stick 'em now if you want; by definition, brackish water fish can adjust to sudden changes in salinity. The plants and the filter bacteria are much more sensitive.
Those fish you have mentioned have all been ones Ive been interested in but then found out I couldnt keep them in my freshwater tank.
Problem solved! Planted, low-salinity brackish water tanks are wonderful things. Leave out pufferfish, and you can include all kinds of invertebrates as well.
I have got plant substrate in there. I have a bottom layer of plant sub, then a layer of fine gravel and then a 1 to 2cm layer of aquarium sand.
Your plants should be happy then. So long as the plants are thriving and basically tolerant of hard water (and not fussed about not getting CO2 fertilisation) they should adapt nicely.

Cheers, Neale
 
I have a 100 liter brackish tank at 1.006 with 3 or 4 BBG's and 2 Figure 8 puffers. When i got the 1st F8 my tank was freshwater but i very slowly raised the SG so my bacteria wouldn't die. Then i added the other F8 and the BBG's when i was at 1.005. Unfortunatly i didnt do very well with the plants and switched to silk ones.. The only live plants i have not killed is the Moss balls..
Here is a pic of my tank after a massive change around last weekend...


Brackish_tank.JPG
 
SG 1.005 is, to be honest, too high for most plants. Unless you have a darn good reason, SG 1.003 should be viewed as the top level for most non-brackish water specialist plants. That's enough salinity for figure-8s, BBGs, knight gobies, mollies, etc.

Cheers, Neale

I have a 100 liter brackish tank at 1.006 with 3 or 4 BBG's and 2 Figure 8 puffers. When i got the 1st F8 my tank was freshwater but i very slowly raised the SG so my bacteria wouldn't die. Then i added the other F8 and the BBG's when i was at 1.005. Unfortunatly i didnt do very well with the plants and switched to silk ones..
 

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