Will java Fern survive in full marine?

[zyquine]

I have some java fern right now for my puffer because it seems to be one of the only plants i can get to live decently in brackish water, but will it survive as i acclimate my tank to full marine?

[marksrush]

No. According to my experience with it, it starts dying shortly after introducing salt into the water, well before you get into mid-range brackish.

[zyquine]

dang, im at about 1.010 and it still seems to be doing ok, can u suggest any plants that will survive brackish to saltwater acclimation?

[marksrush]

Wow that's good! I was kind of expecting mine to last longer, but then I've also read around the net that people say it started dying off for them somewhere around or before 1.008. I did, however, have pretty good luck with dwarf onion: it didn't die as soon as the other plants I had, but it didn't keep growing either.

[LilGreenPuffer]

For saltwater, macroalgae is pretty widely available, and it doesn't actually look like algae.

[Pufferpunk]

Mangroves are about it, as far as I know but I'll PM Neale, to see if he can pitch in on this.

[nmonks]

There actually are a range of plants that do well in brackish water, including several species that naturally occur in brackish water habitats. The problem is that these species tend to prefer low end salinities, up to about 25% seawater, or SG 1.005 at 25 C. The only widely traded mid to high salinity species is Samolus valerandi, which will take almost full strength seawater. However, it's a difficult species to grow, requiring a good substrate and strong lighting.

Sea and turtle grasses are available, and these will do well at mid to high salinities, depending on the species. The same goes for mangroves, though I don't personally rate mangroves very highly given their size: they are, after all, trees, so at best short-term additions to a home aquarium.

Caulerpa species are not particularly tolerant of brackish water, and even the hardiest species will not do well below 75% seawater salinity (less than SG 1.018 at 25 C). There are lots of truly euryhaline algae, some of which are very decorative, but you will need to collect these yourself. The exception here are moss balls, Cladophora aegagropila, which are widely sold but only tolerate low levels of salinity (up to around SG 1.003, maybe a little higher).

Anyway, if you want to grow plants, take a look at my Brackish FAQ for a run through the most widely traded species. Java fern for example generally does very well up to SG 1.005, though I will make the observation that I have never found this species particularly easy to grow, even in freshwater tanks. I tend to recommend people buy one well-established "mother plant" on a bogwood root, rather than trying to establish the species themselves from cuttings or potted plantlets. Another good species is Cryptocoryne ciliata, a big, brackish water specialist widely available via mail order if not often seen in pet stores. The hardy hybrid Crypts are pretty good, too, though they will need to be kept at SG 1.003 or less. Often, the reason plants fail in brackish water isn't the salinity issue but the fact the rest of the system is inadequate: shallow, poor substrate; no fertilisation; lack of strong lighting; and perhaps even lack of CO2 (though most brackish water systems will use bicarbonate from the water instead).

The bottom line is this: if you want plants, keep your fish at a low salinity (25% seawater, or SG 1.005 at 25 C). This is perfectly adequate, if not perhaps ideal, for green spotted puffers. Assuming water quality is good and water chemistry is stable, they aren't going to have a shorter life because they're at SG 1.005 compared with SG 1.015 or 1.025.

On the other hand, if you want a mid to high salinity system, going to whole hog to SG 1.018 or more will allow you to keep seagrasses and Caulerpa spp.

Cheers, Neale

[zyquine]

Thanks for all the suggestions!

[erinmd]

The bamboo shoots that are sold at most pet stores do pretty well at relatively high salinities...I don't know about full marine, but mine did fine in reeeally high end brackish water, even kept growing and sent new shoots out!