Bi-Weekly Discussion of the Week: The switch from FW to SW!!

[Geoff]

Lets discuss what is involved with switching over a tank from FW to SW. What can be reused and what should not be reused. Are there any fish that could handle both environments? What do you do with the FW fish?

G~

[rtgordon]

Originally Posted by Geoff

Lets discuss what is involved with switching over a tank from FW to SW. What can be reused and what should not be reused. Are there any fish that could handle both environments? What do you do with the FW fish?

G~

I recently did this.

I had a 45 corner tank with a penguin 330. I was told that the bacteria was the same and that all I had to do was take out the fish and add salt (that was wrong... i did a little more than that) I set up an 18G aquarium for the FW fish that I wanted and used the substrate from the established tank along with bottled bacteria for instant cycling. I emptied the water and cleaned, bought some cc substrate and filled the tank with sw from the lfs. I kept the penguin running in an ice chest thinking that the bacteria there would be okay for the sw fish. I was told to add some fish or the bacteria would die off. I bought a dwarf fuzzy lion to put in there. I checked the water a few days later to find that I was in the middle of a pretty decent cycle. So, I held off on adding any more fish. I put some pretty cured LR to help with the cycle and after a week everything was fine. The fuzzy doing great... weaned off of live food and is a complete pig. I have a niger trigger and a dwarf zebra lion in there with the fuzzy now. The Niger has developed a touch of ich, and I am starting with the garlic to see if i can take care of it before it has to go to the hospital tank.

I am not using a skimmer and I probably won't at least for a while. I will just keep up with frequent water changes.

I think that mollies can handle both environments. The LFS took back the silver dollars that constantly ate my plants. Many of the filters used in FW tanks will work in a fo sw if that is what you want to do.

[Geoff]

what you have described would work ok for switching over to a FO tank.

for a reef, a skimmer would be a good investment.

now here is an interesting thought. i know, do not use fish to cycle the tank, but bear with me here. if you start with a FW tank with a molly then ever so slowly you add salt to the tank to switch it over to SW. would there be any advantage to this?

G~

[rtgordon]

Originally Posted by Geoff

what you have described would work ok for switching over to a FO tank.

for a reef, a skimmer would be a good investment.

now here is an interesting thought. i know, do not use fish to cycle the tank, but bear with me here. if you start with a FW tank with a molly then ever so slowly you add salt to the tank to switch it over to SW. would there be any advantage to this?

G~

it is a FO With a little bit of LR... I will probably get a nicer skimmer for my reef tank and move the prizm over to the FO tank.

I guess that would work fine if you want mollies in your sw tank It might save a few weeks off of curing with LR/LS.

[dwall174]

Originally Posted by Geoff

I know, do not use fish to cycle the tank, but bear with me here. if you start with a FW tank with a molly then ever so slowly you add salt to the tank to switch it over to SW. would there be any advantage to this?
G~

I did this several years ago! I set-up a 29 gal tank with fresh water using a undergravel filter & crushed coral. I then added six Black Lyretail Mollies (2 males & 4 females) I started adding salt a little at a time (about a shot glass full) every day! After about three weeks or so I was at 1.022 SG.

[Geoff]

did you do any water testing during that? i would be curious to see what kind/ if any cycle you had.

G~

[dwall174]

No I didn't check for any cycling! I did check the SG every other day or so. Being that I used the CC to start with the PH was already around 7.8 so going to 8.2 over a three week time period was not any problem.

[kwjones]

I had a green spotted puffer that I wanted to eventually convert to full salt water, but unfortunately he died of ick, and scaleless fish can't handle many of the popular fresh water medications.

[Geoff]

GSP's are another good choice for this kind of experiment. archer fish and mono's are some more examples.

G~

[kwjones]

A lot of the brackish water species need to be converted to a full saltwater environment as they mature...GSPs, scats, monos and mollies usually do better in a full saltwater set up.

My wife and I haven't decided if we were going to replace our GSP, Hunk, because we had him over a year and got really attached to him. I think he was the main reason we got into saltwater tanks after we found out more about the species.

[tabwyo]

As a FW breeder and supplier I had to handle brackish water fish. The ween from salt to fresh is alot harder than from fresh to salt. Being that most androgenous fish hatch in a FW enviroment and live as adults in a brack or SW enviroment. I toyed with aclimatizing mollies and found that making a fairly drastic (over a period of 7-10 days) from acidic to alkaline water helped. This may simulate the shift in water PH from acid river leech water to a slat water enviroment. Mollies are social fish, as many are, but as a group they have a home area and in a brackish environment thier are drastic shifts in salinity throughout the day(tides, fluctuating water flows from the FW sources). As for the bacteria I would assume that since bacteria are the most robust and adaptable little buggers that they could easily manage the shift back and forth. I did, though, notice a slight incline in my nitrate levels when working the mollies back and forth. Wich would indicate a reduced capacity to process amonia. So I figure there is a die of for the bacteria as well but using establish FW fiter systems reduce the cycle time drastically compared to startin from scratch. I hade a tank with an extremly heavy load on a FW wet/dry. I sold the whole lot and decided for the hell of it to convert it, water and all, to salt to fill a demand for SW feeder fish (mollies). The tank cycled in 22 days with a load of 50 pregnant mollies. I shifted the salintiy in 96 hours from complete fresh to a SG of 1.022. I only lost 5 fish.

[Geoff]

thanks, that is some great info.

what is the biggest expense when switching over from FW to SW?

G~

[kwjones]

Skimmer, lights, LR, water circulation (powerheads/pumps), test kits....livestock

I guess it depends on what kind of FW setup you have. Planted tanks have a lot in common with SW tanks as far some of the hardware needed, like lighting.

[tabwyo]

It also depends on what type of SW system you want to set up. The cost to switch for a FO is very low. You basicaly need salt and food. Now a FOWLR tank incures the cost of LR and possibly an upgrade in lighting. The cost to go from a FW to a reef is basicaly shopping for everythin except the tank. I am up to $1,500 right now converting a 55 gal FW over to a reef. That is alot considering I am biulding alot of the equipment myself.

[Flatfish]

I did the switch back in 2000. I have been progressing towards a reef system ever since. I think the switch is (or can be) more difficult than anticipated. If I had to do it all over again I should have ditched all of the FW equipment and went with all new gear for the SW tank. Here's the story:

BTW - the FW fish two gigantic Oscars - you know how they get - were donated to the LFS.

I started with a 55g. Completely emptied it. Scrubbed it clean with FW only along with its mechanical filter (a Penguin something). I purchased LS, LR and cycled the tank with new SW. Added fish and, inverts all too quickly (typical rookie). After a year I finally got it right.

The real issues cropped up when I started adding corals. I did the typical upgrades with lights, filtration, chems, kits etc. I noticed that while some corals thrived, others fail to acclimate well. I have had several hitchhikers come in on LR purchases where some would bloom with a vengance and others would fail to survive or continuously struggle.

About a year ago I migrated everything from the 55g to a 100g. Part of this migration was to start a 30g system with additional LR and LS to be added to the bigger tank. I played with the 30 for some time. I noticed that corals in the 30 grew nicely. So well that I took more time on the 100g build give me an excuse to play with more corals in the 30.

Finally it was time to migrate to the 100. I added new water and dry sand. Then migrated the contents (LR , LS , fish,inverts and corals) of the 55g and the 30g over time. I reused some of the filtration equipment fomr the 55. A few days after the 30g was emptied, some of the corals either didn't come back well or wasted away. To this day my 100g is hit and miss with corals. I have a variety of corals from softies to acros. Some do well, some don't hardy or not. It's never made sense.

My thinking is that in a FW system we will tend to add chems (like copper based stuff and others) more freely than we would in a SW system. If I had stuck with a FO or FIWLR type system I may have never noticed this. I believe that the equipment carry-over from the FW system was detrimental to my goal of a reef and to date there exists some condition in the tank that may not be resolved without a complete abandonment of the equipment that has come in contact indirectly with the original FW equipment.

Just my thoughts. It's not at all a complete failure here's a recent pic from the left side of the tank:

Joe