Numerous saltwater-to-freshwater conversion questions...

[strawtarget]

I inherited my friend's 24g jbj nanocube because he wants to concentrate his efforts on another tank. He had been using it as a coral reef tank. I'm going to use it as a freshwater tank, so I'm going to need to do some conversion work. I intend to move my 8 panda cory cats over from my 10g tank, and use the 10g tank as a quarantine tank. Then later I want to add 7 or 8 tetras (probably black neons, maybe cardinals if I'm up for some trials and tribulation) and a golden apple snail (Pomacea bridgesii).

Here's my plan...

1. Clean it.
All I've done so far is rinse it out with the garden hose, getting all the remaining sand out.

1a. There are some white spots on a lot of the plastic surfaces, though. They're either mineral deposits or baby corals or something (pardon my ignorance... heh). Should I be concerned about these? Will they leech unwanted stuff into a freshwater setup? Here are some pics.

1b. The backdrop plastic is covered in "stuff". The stuff smells like the beach. I actually don't mind the look of the stuff... it's kinda neat. But I'm worried that in a freshwater environment, it will degrade and start looking bad, or leech unwated substances into the water, or both. So I figure I'll clean all of the "stuff" off. I was thinking "stainless steel scouring pad" or "steel wool" maybe with some vinegar or surfactant-free ammonia that I have left over from cycling my current tank. Hey, it's a cleaning product, right?

Here's a pic of the "stuff".

1c. Once I get all the big chunks off, I was thinking of just running some water/vinegar mix through it for a few days to clean out the pump and whatnot. Good idea or bad idea?


2. Convert it.

2a. The hood comes with two 36 watt 50/50 reef-oriented CF lamps. 72 watts in 24 gallons might be rather much for the tetras I intend to keep. Everything I've read states that they want subdued lighting. Plus, I want a more natural straight 5000k (or 7500k or whatever) light instead of the 50/50 marine light. I can google for replacement lamps well enough, I guess, but I want to be sure that running lower-wattage lamps with the stock electronic ballast (Fulham) is appropriate. It occurred to me that maybe the wattage or frequency of the lamps must match the design wattage/frequency of the ballast, and I'd explode something if I Just plugged in any old lamp with a compatible socket. What's the scoop on this? Here's some pics of the stock lamps...

2b. The tank has a rather novel filtration system. Novel to me, anyway, since I'm used to hang-on-back filters. It has a quasi-overflow design with 3 largish compartments where you can put stuff like filter floss or bio-balls. Water spills into the first compartment, flows down, then into the bottom of the second compartment, then up to the top/middle of the last compartment, then down to the pump, then pushed up a tube to the powerhead and out into the tank.

I don't really know what I'm doing, but I figured I might try some kind of coarse foam block on top of a wad of filter floss in the first compartment, then maybe an activated carbon bag and maybe some bio-balls in the second compartment. Up till now, I've just used Tetra Whisper filter cartridges (and I've never used bio balls or ceramic rings), so I'm not really sure what the best approach would be with this more flexible filtration setup.


Any advice would be greatly appreciated!

 

[fish 'n' fries]

1. I'd guess mineral deposits (but I'm a freshie too...). Vinegar usually works well for cleaning so that sounds reasonable. I've never used ammonia to clean a tank so I'll leave those comments to others.

2. You can definitely get CF lights that aren't actinic if you don't like the coloring. This is just an aesthetic issue. If you're interested in live plants (or might ever be) keeping the actinic would give you enough light for lower light plants without getting into more complicated things like fertilizers or CO2--or you could get "regular" CF lights and have a med to high light tank.

With your ballast you'll need to stick to CF lights. There are retrofit kits but I'm only aware of them going from NO to CF--not the other way around. (Someone may correct me here...)

I've never worried too much about the lights being too bright for the fish (and I've kept lots of tetras over the years)...they may need time to adjust to brighter light though. But my tanks have always been planted so may provide more shade.

3. I'm not familiar with that filter...but your plan sounds reasonable. You want you coarse stuff first in the filter with the finer near the end (so you don't clog the fine stuff with the big particles). You'll find that many folks don't use AC so you could even use just foam and/or bioballs etc. (which just give extra surface for bacteria). There are lots of opinions on what the best choices for filter material are...I personally think any choice probably works fine--depends on your goals.

Enjoy...I'm jealous.

 

[rich311k]

Vinegar and elbow grease should take care of the mineral deposits. Rinse and scrape and you should be able to get it clean.

I would think you would want to put bio media in one of the compartments and floss in another. Should keep your water nice and clean.

That is a good bit of light. If you can add CO2 injection it would make a great planted tank. Otherwise are the bulbs on the same switch or different switches?

 

[Jchillin]

That is a good bit of light. If you can add CO2 injection it would make a great planted tank.

This is probably the best way to save yourself the hassle of going for reduced lighting. Why waste money on lights when you can do this? If interested, head on over to the Planted Tank forum for some tips on achieving this.

 

[severum mama]

Just wanted to add that the stuff on the backdrop plastic is coralline algae. I wouldn't use steel wool because I think the plastic would get all scratched up. Try using an algae scrubber pad and vinegar, and see if that helps.

I don't think you need to worry about keeping tetras. They will really like the plant cover even if they don't like bright light, and they'll just hang out in your plants.

 

[strawtarget]

Cleaning...

Vinegar and a normal scrubbing pad did the trick. Quite well, actually... quite a bit less elbow-grease than I imagined.

I also ran the pump in a bucket of vinegar for a couple hours, then added an equal amount of water and let it run for several more hours. Then I just let it run overnight in straight tap water to flush it out. The pump innards didn't look too crustified, but I figured it couldn't hurt.


Lighting...

The actinic looks great for marine stuff, but I just don't think it will work well for the look I'm going for. The 2 lamps are each 50/50 and are all on one switch, so it's all or nothing... otherwise I'd just turn off the actinic and be done with it.

I'm definitely going to stick with CF lamps in the stock fixture, but I'm still curious if I can run lower wattage CF lamps with the existing ballast. I can't imagine why not, but I want to be sure before I spend any money on lamps. I might shoot Fulham an email, or try to find some kind of CFL faq on a non-aquarium site somewhere.

I really don't want to mess with CO2 injection. My plan is to grow anubias, java fern, java moss, water sprite (1 floating, 1 planted), and hornwort (floating). I'm hoping that this setup will not be too demanding: I can just dose a bit of Flourish and that's it. I guess I should make a separate post in the planted tank forum as y'all suggest. (EDIT: Done. Here's my planted-tanks forum post.)

 

[7Enigma]

I'd try the lights out first once you get it all set up. I just switched back to 50/50 from my 6700k bulbs and prefer the look of the 50/50 on my FW setup. The greens now have different shades of blue in them and it really brings out the colors of my fish (tiger barbs and powder blue flame gourami).

One thing you could try and see how bad it looks is to remove one of the bulbs and cover the wiring with duct tape (to prevent corrosion of the connector). This would be a quick and easy way to 1/2 the lighting but I don't know how uneven it would throw. I also don't know if a removed bulb will cause the lighting system to not light the remaining bulb. But its worth a shot.

And I started out just like you with a similar plant list. Then I upgraded my lights, dabbled with ferts, set up a DIY CO2, and will soon be completing the transition with a pressurized CO2 setup. Just you wait!

 

[majolo]

I'd try the lights out first once you get it all set up. I just switched back to 50/50 from my 6700k bulbs and prefer the look of the 50/50 on my FW setup. The greens now have different shades of blue in them and it really brings out the colors of my fish (tiger barbs and powder blue flame gourami).

I agree with this. I had black neons in 50-50 lighting for a while, and their stripes practically fluoresced, very cool looking.

 

[Devilishturtles]

The white little specs are tubeworms, a type of feather duster worm. They should just chip right off with a blade, but if they don't they pose no harm.

I like 50/50 too. 5000k to 6700k looks very yellow.

 

[littlerob904]

I've been combing the internet for this exact question and I'm excited to see I'm not the only one trying to convert a saltwater tank to freshwater. How did everything turn out?

I just recieved a 75gallon acrylic saltwater setup from a coworker and will be trying to convert everything to freshwater, mostly due to cost, and maintenance effort. I'm not looking for the commitment of a saltwater tank yet, at least not until I learn more about what I'm doing.

The filtration setup you have is called a wet/dry, it's similiar to what I have built in to the rear of my tank. Mine is a Tenecor Simplicity system. For mechanical and chemical filtration I plan on using filter floss, one of those blue and white filter pads, and a media bag full of active carbon. For biological filtration I plan on using the bio balls that came from the saltwater setup.

The main question I have, is vinegar the best thing to clean with? Many other sources have suggested a 10% bleach solution. And I have recieved conflicting reports that it is ok to just rinse the bio balls and use the same bacteria from the saltware setup. Could this cause issues with diseases from the saltwater fish infecting the freshwater fish? I was figuring to clean the entire tank, hoses, powerhead, bio balls with a bleach solution, and introduce new media for the rest of the filtration. Is this overkill? Would I be better off not bleaching the bio balls and trying to keep some of the good bacteria? I plan on purchasing gravel for the substrate and not using any of the rocks / coral from the saltware setup as I figured they would be far to difficult to clean effectively.

I look forward to using this forum more often, it seems like a great resource.

 

[Hairy_Harold]

Just try bleach or chlorine and rinse with vinegar should be right for cleaning.

You will be able to get lower wattage tubes the ballasts just take a maximum light you can always have less powerful lights in there. The 10000k light will grow plants greatly though so maybe get 2 4000k and 2 10000k for growth and looks.

The filter will work great for the tank, i'd just have some course sponge, filler wool and ceramic noodles. Carbon is useless and needs replacing, if you want that extra something try Seachem Purigen as it can be washed and renewed instead of thrown out.