# Tank Conversion from Salt Water to Freshwater



## bingerz (Mar 3, 2011)

I've got an acrylic tank roughly about 195 gallons that was given to me. It was previously a saltwater tank and it's got a built in sump. I want to convert it to freshwater and put my africans in there. How do i go about cleaning it out and making it ready for africans? I've done some searching/reading on the web and on here. Some people are saying to use some bleach, some others are saying to use vinegar. I was thinking about using a spray bottle mix (water/vinegar) w/ a toothbrush and rag and elbow grease. There's just no way I could take this thing out and hose it down outside, cuz of the sheer size and weight of it, plus it's freezing out. So I would wash it down and siphon out the water straight into the drain. And/or fill it up and just let it run for a week or so while doing water changes and monitoring water conditions.

I don't know anything about keeping marine fish, but i've read that the water is a higher pH and africans like that. Do you think I still have to really get in there and completely wipe out/clean/nuke the tank? The tank right now is completely bone dry and has been dry for months, maybe a year even, sitting in storage. After a little cleaning, do you think that a disease would still survive and be carried from saltwater into freshwater? It also came with some bioballs...should I completely bleach them? Would hot water suffice? Any advice is greatly appreciated! Thanks!


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## Flear (Dec 8, 2012)

i don't know about converting.
i would think (guessing) bacteria that are suited for saltwater will die in freshwater (regular tank cycling should deal with that)
if your using vinegar may be good, although i think acetic acid dries to a power instead of evaporates 

more guessing, any trace nutrients that are stuck to the glass are probably going to be low enough not to impact the freshwater environment.

due to the different environments between saltwater & freshwater, ... personally (only personally), i wouldn't worry too much, a general wipe down and good to go, set it up how you want, let the tank cycle. ... if your still unsure, add a few fish, see how they do.

i would say "personally" i'd do this, as if i was in your shoes and something unexpected happened, i've gotta empty the tank and do a more extensive cleaning.

maybe i'm a little more risky, a little less cautious, but that's me, and my take on such a tank


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## MEDHBSI (Sep 4, 2011)

to clean my bioballs i usually just put them in a mesh bag and throw them in the washing machine on light cycle with no soap. I think the only thing you might have to worry about is the leftover salt in the tank so i would go with what your planning water/vinegar and elbow grease. I'm sure alot more people will post on this topic just give it time.


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## AdamsB (Oct 18, 2011)

I think as stated already, elbow grease will be the biggest asset. I took an old salt water tank before and made it fresh. There were a few water stains and some coralife algae but a razor blade took the algae off and a good scrub with a cloth took out most of the water stains. I was advised to use vinegar on the stains but they didn't bother me too much so I didn't bother. It was around 30 gallons. So I gave the whole thing a scrub down while it had a couple of gallons in it. Then I filled it and wiped down the sides again. Emptied the water, filled for the second time and started the cycle. I ran it for 6 months with no issues. My tiger barbs even spawned a few times in there. 

So in my view, if it looks clean enough for you to use, and doesn't smell. Go with it. The smell could be a sign of grime you would want to remove. Smell is in essence bacteria.


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## Rastapus (Apr 21, 2010)

bingerz said:


> I've got an acrylic tank roughly about 195 gallons that was given to me. It was previously a saltwater tank and it's got a built in sump. I want to convert it to freshwater and put my africans in there. How do i go about cleaning it out and making it ready for africans? I've done some searching/reading on the web and on here. Some people are saying to use some bleach, some others are saying to use vinegar. I was thinking about using a spray bottle mix (water/vinegar) w/ a toothbrush and rag and elbow grease. There's just no way I could take this thing out and hose it down outside, cuz of the sheer size and weight of it, plus it's freezing out. So I would wash it down and siphon out the water straight into the drain. And/or fill it up and just let it run for a week or so while doing water changes and monitoring water conditions.
> 
> I don't know anything about keeping marine fish, but i've read that the water is a higher pH and africans like that. Do you think I still have to really get in there and completely wipe out/clean/nuke the tank? The tank right now is completely bone dry and has been dry for months, maybe a year even, sitting in storage. After a little cleaning, do you think that a disease would still survive and be carried from saltwater into freshwater? It also came with some bioballs...should I completely bleach them? Would hot water suffice? Any advice is greatly appreciated! Thanks!


Honestly just rinse off everything, any salt residue would benefit Africans, not hurt them. If everything has been sitting dry a rinse is all you need. Be very careful with the acrylic of course, very easy to scratch. Make sure you are using only acrylic safe pads when cleaning it.


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## bingerz (Mar 3, 2011)

thanks everyone for all the help. I'm gonna start putting it together this week. hopefully i'll have it somewhat running this week, that's a lot of water.


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## bingerz (Mar 3, 2011)

so i cleaned up the tank...but what's kinda stumped me is the sump in the back of the tank. i drew a picture of it....maybe someone could shed some light on the subject. What i don't understand is how the water gets from chamber 2 to chamber 3, for the return pump to pump the water back into the tank. okay...so i know the water goes into the overflow (chamber 1), fills up and cascades down into chamber 2 where the bio balls are at. There's a plate there with holes in it. Shouldn't the water fall thru the holes and onto the bioballs? I thought that there has to be moving water thru the bio balls. OR does chamber 2 fill up? The baffle between 2 and 3 is higher than the one between 1 and 2 and there are no holes in the 2nd baffle.

This is where I think the protein skimmer comes into play. I think the previous owner used the skimmer to suck up the water from chamber 2 and drop into chamber 3. Does that sound right? Is that how he got the water from 2 to 3? I've read online that protein skimmers aren't for freshwater, i've never used one myself - but while watching some youtube videos...i noticed one guy had one connected to his tank full of oscars. So i dunno. Also, It just seems weird to me that the bio balls would just sit there without running water thru them - but I'm new to sumps and setups like these.

you guys have been great thanks for all the info so far!! Thanks so much!


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## kacairns (Apr 10, 2012)

bingerz said:


> View attachment 14054
> 
> 
> so i cleaned up the tank...but what's kinda stumped me is the sump in the back of the tank. i drew a picture of it....maybe someone could shed some light on the subject. What i don't understand is how the water gets from chamber 2 to chamber 3, for the return pump to pump the water back into the tank. okay...so i know the water goes into the overflow (chamber 1), fills up and cascades down into chamber 2 where the bio balls are at. There's a plate there with holes in it. Shouldn't the water fall thru the holes and onto the bioballs? I thought that there has to be moving water thru the bio balls. OR does chamber 2 fill up? The baffle between 2 and 3 is higher than the one between 1 and 2 and there are no holes in the 2nd baffle.
> ...


If you look at the plate between chamber 2 and 3 somewhere near the bottom you should find holes or a gap so water can go into chamber 3 based on your picture


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## tony1928 (Apr 22, 2010)

My old sump had the water flow through a plate with holes and onto the bio balls. The bio balls should not be submerged but just wet to work the best.


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## bingerz (Mar 3, 2011)

kacairns said:


> If you look at the plate between chamber 2 and 3 somewhere near the bottom you should find holes or a gap so water can go into chamber 3 based on your picture


Last night i took out all the bio-balls and with some investigation, I noticed the gap at the bottom of the 2nd baffle leading into chamber 3. It was small though, like 1/2".


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## bingerz (Mar 3, 2011)

tony1928 said:


> My old sump had the water flow through a plate with holes and onto the bio balls. The bio balls should not be submerged but just wet to work the best.


my drawing isn't up to scale, so there may be more space to lift the bioballs from off the bottom and maybe put them in the middle suspended between two plates w/ holes. I'll see if it fits, thanks for the info!


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## tony1928 (Apr 22, 2010)

You could easily build that yourself if there isn't something already there. Mine was done with a piece of eggcrate/light diffuser cut to size and supported off the bottom with a acrylic lip. You don't need the lip, you could just support it with a few pieces of PVC pipe. Like feet. If you want to submerge the biomedia, then just use a proper media like Matrix or some sort of ceramic biomedia like Eheim Substratpro. I would still build the support though to keep the media off the bottom, maybe an inch or so. Helps with water flow and ease of cleaning. Also keeping your media in plastic baskets makes life easier too.



bingerz said:


> my drawing isn't up to scale, so there may be more space to lift the bioballs from off the bottom and maybe put them in the middle suspended between two plates w/ holes. I'll see if it fits, thanks for the info!


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