:o Hi, my name is Jess and I've been trying to find info for some time. I recently purchased two small green spotted puffers from the pet store believing they were freshwater fish. I was also told they would stay small and a 5 gallon tank was OK. Well, still small and happy in the 5 gallon tank I have found out they are actually brackish water fish and will live longer healthier lives if I maintain a brackish aquarium. Not to mention they will grow to 6 inches! I just purchased a 30 gallon aquarium and have been running it a few days. I boiled real seashells for the bottom and have had nothing else in the tank yet but the heater and the filter. I don't want to kill the fish when I put them in but I don't know much about cycling the tank or anything like that. I added a cup of water from the tank the fish are in now assuming that will help with the good bacteria? I have tested the pH and Alkalinity(which I assumed where the same things but guess not?) and they are in the paramiters for a brackish fish. However, I do not know what the nitrate and nitrite levels should be. I am also not sure as to whether I shuold buy testing kits, water conditioners, etc. for salt water or for fresh water because I have not found anything in the stores or online for specifically brackish water. Does it even make a difference?I know in real life conditions the salinity and everything would fluxuate daily but I've also found a lot of conflicting ideas as to what the salinityand all that of the tank should be. If anyone has any advice for me before I attempt to put my perfectly healthy fish into a much bigger better tank, please let me know! Thanks

Jess

Hi, yes, I have a lot of info for you on how to set up a brackish environment. Unfortunately, it's all in my head. So, give me till tonight after I put my kids to bed and I'll type it all up for you.
For the meantime, don't worry about your puffers. They have been conditioned for the freshwater environment you have them in.
Setting up and maintaining a brackish water aquarium is a very delicate process and the puffers will need to be conditioned for the change first.

Also, once you've switched to brackish water, you can't go back to fresh water without risking the life of your puffers. Brackish water aquariums are harder and more expensive to maintain as well. There is a lot more to this and boiling shells isn't going to work...

I'll also give you a list of the materials and test kits you'll need.

Then you can better make your decision as if you want to make the change or not.

Kae

Brackish water occurs wherever rivers meet the ocean and has a salinity in between freshwater and seawater. The key difference between fresh water and brackish water is the water chemistry.
Brackish water needs to be hard, alkaline, and contain about 10% to 50% of the salt in normal seawater.
Brackish water is typically maintained at a specific gravity (salinity) of 1.002 (further up the river) to 1.020 (close to the entrance to the sea).
All the brackish water environments estuaries, mangrove swamps, and salt marshes, have a different specific gravity or salinity.

You have probably encountered so many conflicting salinity measurements from different fish keepers because of the species being kept and whether they live close to the ocean where the salinity is higher, or further up where the salinity is lower.
Also, some species of fish live closer to the ocean when adults and swim toward freshwater to breed. As a result of this, their fry live their young lives in water with less salinity. As they get older, they move down closer to the ocean where the water has a higher salinity, only returning closer to the freshwater to breed. So, many fish keepers need to adjust their salinity depending on the age and size of their fish (which you will need to do).

You will need

Water Conditioner: to remove chlorine and chloramine from your tap water before placing it in the tank

Marine salt (Instant Ocean/natures ocean) NOT freshwater salt, sea salt, rock salt or any other salt not labeled for marine use.

Hydrometer: to measure the salinity of the water

Filter: You can use hang on back or canisters. For brackish set ups, the water needs to be turned around no less than 10 times per hour and you'll need a single 300gph filter or two 150gph filters for a 30g tank

Air pump: lots of oxygen bubbles needed

protein skimmer: this is optional in a brackish tank. If your water appears foamy at times, you may want to invest in one.

Submersible heater for fresh and salt water aquariums

Thermometer: water needs to be kept at 80 - 84 degree F

Substrate: crushed coral or marine aragonite sand. This substrate is important because this is what's going to stabilize the alkalinity and protect from huge PH drops, provide the calcium needed for the environment, and harden the water. (what I think you were trying to do by boiling the shells, but who ever told you to do that was wrong as it is dangerous to the fish and can and will create unstable water conditions)

Water testing kit for fresh and salt water aquariums. This is a kit that includes everything you will need to test your water to make sure the chemistry is correct in all aspects.

*Your aquarium should have a hood and space covers. The water from any type of saltwater environment will evaporate very quickly; however the salt does not evaporate and salinity is higher in a tank that water has been allowed to evaporate from. When water has evaporated you replace the water with fresh water. Only when making water changes you add salt.


The Set Up

1) you need to empty out all the boiled shell water from the tank.
2) After rinsing the substrate (crushed coral or marine aragonite sand), put a very thin layer just covering the bottom of tank.
3) mount your filters and air diffusers
4) add conditioned fresh water to the tank (leave 5 gallons of space for your other tanks water), and place heater underwater - wait till water is same temp as water fish are in
5) Just before placing your fish in the new tank, you will need to put their filter media (the cartridge. Bio-sponge or bio wheel in the new filters). The reason for this is because the beneficial bacteria that keep the tank health live in this media. Adding the filter media from a cycled tank keeps the cycle going.
6) add fish and aquarium water, then run tank for a week
7) test water, your tank needs to be cycled before you start the conditioning of your fish. Your water should read ammonia 0ppm, nitrites 0ppm, nitrates should be no more than 30ppm. You can tell if your tank has cycled by having a nitrate reading.

You need to condition your fish...

You have a green spotted puffer, their water will need to have a specific gravity (the salinity of the water) of around 1.010 -1.020 depending on their age and size.
1.010 for 2 inches and under / 1.015 for 4 inches and under / 1.020 for 6 inches and under.
This needs to be done very, very slowly. You should only raise the specific gravity .002/week until you've reached 1.010 (for 2 inches and under).
Check your specific gravity using the Hydrometer and record it. You do not want to exceed .002 within a week.
I would suggest adding 2 cups of marine salt a week. Add one tablespoon at a time at least 3 hours apart for 7 days (a little more or less may be required, just make sure the 2 cups goes into the tank evenly throughout the week). Make sure you keep an eye on your specific gravity. Check it throughout every day to ensure that it's not going over .002 or raising to quickly.

*The measurements that I go by for my tanks are 1 cup of marine salt to raise 5 gallons of water .005 (which in your case would be 6 cups in a 30 gallons if you wanted to raise the specific gravity .005), but you only want to raise yours .002 so I'm estimating that you use 2 cups instead. You must keep an eye on this because I'm estimating by dividing in half of what I do and leaving a little leway...

Please go about this change with caution. It is very important that your 5 gallon tank is cycled before you add the puffers to the larger tank with the crushed coral or marine aragonite sand.
This substrate hardens the water and creates a high alkalinity and PH which is not suitable conditions for cycling a tank with puffers.
Also, freshwater bacteria is different than saltwater bacteria and it's important to have a good freshwater bacterial colony established to hold over while the saltwater bacterial colonies develop.
As the saltwater bacteria bloom, the freshwater bacteria die. This clouds the water so don't be alarmed - it must happen and it will clear up on its own.

Please let me know if you have any other questions. I'll be happy to help. And I don't mind walking you through this process step by step...

Kae

Thank you so much! That helped me a lot! The first question I have is that both tanks have a sg of 1.000 should I raise both tanks or put them in the larger tank and then raise it slowly? Also, if they are in the 30 gallon and I need to raise the salt do I add salt water or can I just put the salt directly into the tank? Also, did you mean to say I should remove the shells and replace with something from the petstore? Thank you again and if you can get back to me on these questions that would be great.

Thanks
Jess

The water in your 30 gallon needs to be emptied and replaced with freshwater that has not been boiled with shells.
Since the shells were boiled, they will end up dissolving at a fast rate which will cause undesired and unstable water fluctuations. Using crushed coral or marine aragonite sand for the gravel will buff your water for constant PH, alkalinity, and hardness support. You can buy this at a pet shop.
Are your fish living in freshwater right now?
If so, your fish need to live in freshwater in the 30 gallon until you know for sure that the tank has cycled. Then, extremely slow, the marine salt can be added. But you don't want to be adding marine salt yet.
During the period of raising your salinity level, designate a cup, fill it with tank water, dissolve 1 tablespoon of marine salt, and slowly poor it back into the tank away from fish. Never add more than 1 tablespoon of marine salt in a 3 hour time.
Later on, when doing water changes, you can use a 5 gallon bucket to prepare the water before poring into tank.

The first step in this process would be setting up your 30 gallon aquarium with the freshwater (if your puffers are in fresh water now)that has not been boiled with shells.
You can use shells in the tank for décor, but don't boil them.

Thanks so much for all the info! It's a GREAT help! Yah they are in fresh water right now so I will just sustain that for now. I'm so excited to get those guys in there!

Your Welcome!
A test kit that tests alkalinity, hardness, ammonia, nitrites, and nitrates is good to have so that you can keep a close eye on the water chemistry and the nitrogen cycle.
When you transfer the fish to the 30 gallon, don't forget to place the filter media from the 5 gallons filters inside the filters you have for the 30 gallon.
Let them live in the 30 gallon in fresh water for about a week, then you'll need to run some water tests to make sure everything is perfect before beginning the conditioning process with the marine salt.

Any questions you have I'll be happy to answer them for you.

Kae