Brackish Newbie

[twiztedblade]

Hey guys, just joined the forum recently and have been reading some of the topics around here. I just have a couple of concerns that I need to ask.

Setup:
33g tall brackish tank with SG of about 1.0
2 - Whisper 40 filters. One has an extension to reach the near bottom of the tank while the other one is normal length.
Submersible heater
Enough fake plants, rocks for everyone to hide behind
2 - .75" GSPs (Humpty and Dumpty)
2 - 3" Sailfin Mollies (Larry, Curly) Moe died last week. His fins were tragically massacred by the puffers. Somehow he was the weak one since the other 2 mollies still have their fins.
1- pleco. I have no idea how he is surviving in this tank but he has been helping with the maintenance
1 - black spotted spiny eel (Eli). Amazingly, he is very friendly with the other fishes

1. Do you think my tank is overcrowded? I was thinking of keeping it 33g for now (since the fishes are still small) but would update to a bigger one later (when the puffers and the eel gets bigger).

2. I feed the fishes twice a day with just 1 block of bloodworms per feed. I think it is enough but it seems like they are still hungry. Or are they just ALWAYS hungry? Should I try feeding them other food? If so, what?

3. Is it just me or are brackish tanks really dirty?! I have read about the high maintenance of these tanks hence why I tried to get a cleaner (pleco) and 2 filters. I do water changes once a week (sometimes twice) but I still see algae growing on the rocks and the fake plants. What else could I do?

4. Right now I use the non-iodized salt the LFS sold me to slowly increase the SG. Should I keep using this or should I use coral substrate? And is an SG of about 1.0 sufficient right now or should I try to get it to 1.01?

Thanks in advance!

 

[nmonks]

Hello!

There are several issues with your tank, but oddly enough overstocking probably isn't the most serious of them. In short, you have a mix of fish that, in the long term, won't work.

Specifically, the plec and spiny eel are freshwater fish. Yes, there are species of both that occur in slightly brackish water, but your species aren't among them. Moreover, even the species of plec and spiny eel that do tolerate (or prefer) brackish water only want an SG well below that which the puffers will need.

The mollies will adapt to anything right the way up to seawater, so salinity isn't the issue there. As you've discovered, they do tend to get targetted by puffers. In my experienced, puffers will attack livebearers and Corydoras catfish even where they ignore other things like tetras and Otocinclus. I think the issue is stupidity. Neither livebearers nor Corydoras have any sense of territory or danger. Possibly it's been bred out of them, since both have been bred for decades to make agreeable aquarium fish. Whatever the reason, I would move the mollies away from the puffers.

Green spotted puffers (of either species) need at least brackish water of SG 1.010, i.e., half-strength seawater. Some would argue fully marine conditions are to be preferred for adults. Regardless, you cannot keep them at the salinities that spiny eels or plecs will tolerate.

Non-iodized cooking sea salt is fine for a stop-gap measure, but it isn't adequate over the long term. You need proper marine salt mix, which you can obtain from most aquarium shops. Do not use "aquarium tonic salt".

The measurements you quote for SG seem a bit off. "1.0" would be 1.000, i.e., fresh water. Sea water is 1.018+, with brackish water typically being around 1.003 to 1.010, depending on the fish being kept. Note that SG is always quoted to 3 decimal places. I don't know why, but possibly to make sure people don't confuse 1.001 with 1.010, etc.

Coral sand has no effect on SG. It has a modest effect on pH and hardness, so it's worth using with mid to high-end brackish water fish. But after a while it gets covered in algae and bacteria, and isn't nearly as good a buffering agent as the marine mix itself.

Hope this helps,

Neale

 

[twiztedblade]

Hey Neale

Actually, the tank started out as a freshwater with just the pleco and the eel in there. But as I went into the LFS, those puffers just made me want them. So I started my research on them and started to turn my tank into brackish. I only have the sg at around 1.000 because the lfs that I got them from started them in a freshwater tank (new arrivals). I will try to get it to 1.010 in the next 2 week2. I have read that mollies would be an ok tankmate with the puffers hence why I got them. I just never knew the puffers would chew the crap out of their fins.

I will try to move the pleco and the eel to a 10g freshwater for now. I know those eels would grow larger but a 10 should be ok... right?

As for the mollies, I did notice that the other 2 do not have any bites or fins bitten off. I'll probably try to move them to the 10g unless the puffers will leave those 2 alone.

So with 2 tiny puffers in my 33g, any ideas of what other fishes I can get? I know I dont want archers because they will get huge.

Thanks for the reply!

 

[nmonks]

Choosing tankmates for puffers is a very inexact science. Some people have great success, others find it impossible to mix their pufferfish with other species. Certain species tend to be more peaceful than others, but even then, there don't seem to be any guarantees. I keep South American puffers, which are basically tolerant and easy-going, but they do nip specific types of fish (livebearers, Corydoras, and gobies other than bumblebees). All I can say is that as far as the brackish species go, GSPs seem _usually_ not good community fish, whereas figure-8s are said to be _somewhat_ acceptable community fish. I haven't kept either species, so cannot speak from experience. This article is probably about as good a review on these fish as I've read. Once you've digested that, then you can think about tankmates. But seriously, these fish can become aggressive very quickly, so you need either a bigger tank so that you can have ultra-fast tankmates (e.g. monos) or fish that can handle themselves and will be able to fight back. Possibly something semi-aggressive, like a black-chin tilapia or one of the brackish/marine tolerant Central American cichlids.

Your other problem with GSPs is that they get quite big. Expect at least 12 cm per fish, possibly anything up to 15 cm. A single specimen in a 30 gallon tank should be fine, but two is a gamble because they may turn out to be territorial. We can't sex these fish, but if you have two males, it's likely they will squabble. That you're raising them together my help, but there's no guarantees there, either.

A generic plec can get to something like 20 cm within a couple of years, and many specimens exceed 30 cm. A 10 gallon tank is merely a temporary home for such fish. If you can, try and exchange him for something a little more manageable, like a bristlenose plec or a clown plec. I'm not 100% sure which spiny eel is currently being sold as a zebra spiny eel. Even the smallest spiny eels exceed 15 cm, and chances are this fish will get to about 20 cm or so if it does well, so again, a 10 gallon tank is definitely not optimal. Spiny eels are quite awkward fish in all kinds of ways. CFC wrote a very nice index file for one kind of spiny eel, but it can be applied to pretty much all species. While CFC says a sand substrate is nice, I'd say it's essential. Spiny eels damage themselves burrowing into gravel, and once a mysterious bacterial infection sets in, and it will, then the eel dies. To avoid this, give it a tank with silver sand.

Cheers,

Neale