Converting Freshwater To Brackish

[clareanded]

Hi there,

We were hoping to get some advise on how to convert a freshwater tropical tank to brackish water. The tank was only purchased and setup 1 week ago but due to our potential choice of fish (celyon aka green puffers) may need to convert to brackish water.

Is this just as simple as adding the correction ratio of sea salt to the water, purchasing a test kit to ensure the density / gravity of the water is maintained?

Can we still use gravel and the same plants in the tank or must it change to sand and specific brackish water plants???

Any help / advise is very welcome.

Many Thanks,

Clare & Ed

 

[Puffdaddy]

O.K. having a brackish tank is easier than most people think. You basically have the right idea, just add marine salt till you
reach the desired specific gravity (sg) using a hydrometer. No other extra equipment that is needed. And yes Ceylon Puffers do need brackish water. Is your tank cycled yet or in the process of cycling? Also how big is your tank?

 

[clareanded]

Ok, that is really good to know. Thank you.

The tank is still in the process of cycling and is a 200L.

We've been told that this could easily house 3 Celyon's (which grow to about 8" inches) so long as the tank is well planted and they have areas to hide. Do that sound right, in your view?

 

[Puffdaddy]

Yes that tank is plenty big enough for 3 Ceylon Puffers. Be careful when buying sometimes they are missed labeled. Be sure to get the scientific name when you buy. Sometimes people and fish stores get the Green Spotted and Ceylon Puffers mixed up. Also the Ceylon will reach a size closer to 6" for adults and rarely will you see one 8" in captivity.

Ceylon Puffer: Tetraodon fluviatilis
Green Spotted Puffer: Tetraodon nigroviridis
Figure Eight Puffer: Tetraodon biocellatus

The Ceylon will look like a cross between the other two with an abstract figure eight on top and black spots down the sides.
Anything else? /

 

[clareanded]

It is so funny you should say that! The place where found them had them labelled as Indian Puffers which, when we researched only grow to 2". So I did go back and get the scientific name which was Tetraodon fluviatilis.

No more questions, thank you for all your help.

 

[smooth_bourbon]

Ask the specifics on the water the pet store is keeping them in. People have a very wide opinion of what brackish is, not to mention a lot of stores keep the fish in fresh water as juvinal. It will be a lot easier on the fish if you adjust your water to match and then slowly get it to what it should be. And have you checked into anything to buffer, or do you already have hard water? Also plants will be a challange.

 

[Tessla]

Here's a good profile on Ceylon puffers if you want some more info on them. I'd only keep a single puffer in your tank as they'll grow rather large. Your best course of action would probably be to go full marine (gradually!), then add some live rock for filtration and treat it like a marine tank, nitrates are considerably more toxic in marine conditions than in fresh, check out the saltwater section.

The only common plants I know of that will live in brackish are java ferns, but they'll only tolerate low end brackish. If you want live plants, wait until you get to full marine conditions and add some marine macroalgae.

 

[bymauldin]

Ok, that is really good to know. Thank you.

The tank is still in the process of cycling and is a 200L.

We've been told that this could easily house 3 Celyon's (which grow to about 8" inches) so long as the tank is well planted and they have areas to hide. Do that sound right, in your view?

How far along are you with your cycle? If you've just started it's best to go ahead and add the salt to the SG of the fish you're wanting. That way the tank will cycle with brackish water. If you've been cycling for awhile and don't want to start over-it would be best to gradually raise the salinity of the water (weekly) once your tank has finished cycling. If your tank has cycled as a FW and you suddenly dump all this salt in the water it could potentially kill off all your bacteria and you'd have to start the cycling process all over again. You definately do not want puffers in a tank that is cycling as they are very sensitive to water changes.

 

[Puffdaddy]

WoW - you tasted the water, that can't be good.

First off congrats on your new puffer. Awesome choice. I have 2 adults in a 30gl tank myself.

Here are some pointers and questions that should help you. PH is fine (7.6-8.2) and so is your temp (72-82*F), nitrate within range (less than 30 ppm). My first question, has your tank been cycled yet? If not you should help that along as soon as possible. Puffers are very sensitive to ammonia and nitrite. Both should remain 0, though you well have bumps now and again, "water changes, water changes, water changes" that's the key.

Now your salinity issue. I'm a little confused about your hydrometer "calculate 24hrs" must be a classy one. You should also get one that gives you an instant reading, for example a floating one. That type of hydrometer is cheap, quick and perfect for use in a 5gl bucket you can use for water changes. However your salinity level well likely end up being just fine.

My personal beliefs are this:
very young*= 1.000-1.002 *meaning after birth + shipping
young*= 1.002-1.006 *day you brought home -3 months
adolescent 1*= 1.006-1.010 *3-6 months
adolescent 2*= 1.010-1.014 *6 months-1 year
adolescent 3*= 1.014-1.018 *1-2 years
adult*= 1.018-full marine *2 years +

I also strongly believe in fluctuating the salinity within the settings to imitate the wild. Now these are just my personal beliefs based on years of experience. These are in no way "the rules". And yes you need marine salt such as Instant Ocean.

More misalanious tips:
*must feed snails to them to keep teeth trimmed
*puffers are carnivores so feed them meaty foods frozen and/or live
*vacuum substrate during every water change
*move decor around during every water change to imitate wild (puffers are also very curious and like to buzz around
searching new scenery)
*puffers do like to lay around on the substrate especially when no one is in the room to watch them
*do not make them puff up
*very aggressive fish well not tolerate very many tank mates I recommend keeping it in a species tank
*If your going to keep more than one, get them now so they can grow together
*puffer also change colors don't worry it's normal, although a white belly is a happy fish
*if tail is curled tightly to side it's stressed and or scared
*although prolonged dark belly, curled tail and sitting on the bottom indicates that something is wrong (water? or illness?)

If you have any other questions just ask.

Here is a post I put up some time back they talks about Green Spotted Puffers. Everything above applys to Ceylon Puffers as well I hope this Helps. Especially the specific gravity chart

 

[clareanded]

Thanks for all the info guys!!

Our tank has been cycling freshwater for one week. Things are a bit up the wall at the moment so to speak as the Ceylon's we want to purchase are not yet for sale as they are unwell. For now we are just holding fire until we know if they are going to make it (fingers crossed that they do). If we have to convert to brackish water then we will have to start the cycle over again. It is annoying but we need to know these fish are going to full recover before we replicate their environment here.

We think the store may have upset the puffers by keeping them with other fish (cat fish I think) and they seem quite young (only 2 inches) and are huddling together up the corner of the tank and all have black stomachs. I though it was weird that they would all be so close together as from everything I've read they like space from one another....??

One final thing that I am still not clear on is would we have to use fine gravel / sand as a substrate (for brackish water conditions)? At present we have just normal gravel. Could we use a combination of sand / gravel?

Cheers,

Ed and Clare

 

[Puffdaddy]

I think the best substrate to use in a brackish tank is Aragonite, you can also add crushed coral. These will help keep the water buffered and on the hard side. Although you can basicaly use what ever you want.