Local northern ocean water in a reef tank

[Shaun Sweeney]

I live on Vancouver Island in BC Canada and I'm almost within a rock's throw of the ocean so I've decided to use our local water in my tanks. The salinity is .20 and can easily be brought up to the required .26. Interestingly, if I use Red Sea Coral Pro salt to make up the difference, all of the parameters come into line.

My question is whether or not I should treat the ocean water prior to use. I could easily apply some serious UV filtration. Of course, I do primary mechanical filtration when I collect the water.

Comments anyone?

 

[airmotive]

Waaaaay too many things to wrong with natural seawater.
I could see using it if salt mix was $100 an ounce, or if you had a 20,000 gallon system, or if you lived beach side on a secluded South Pacific island, where your tank residents are harvested from the same water.

But you're taking water from one of the most industrialized part of the ocean, with biology, pollutants and chemistry completely foreign to tropical reef biology, all to save...$50-100? Unless you do very large water changes all the time, any pollutants you introduce will accumulate and concentrate. Lots of agricultural and industrial runoff in your area. It's not the Gulf of Mexico, but it's significant.

If you're making a cold water tank with biology typical of Vancouver (which would be pretty cool, BTW), then 'maybe'. But you'll also find that hauling hundreds of pounds of water in buckets every week gets really old!
My advice: just buy the bucket of salt and enjoy the extra free time drinking a beer or two at The Flying Beaver.

 

[cmcimino]

I live by the beach in North Carolina, and the local university in town has an aquaculture center down the road from me where I get filtered sea water. It is UV filtered and ran through a series of sand filters. Parameters are usually at desired levels, all though I do boost the alkalinity form 7 dKH to 8.5 dKH. I'm not sure I would use unfiltered seawater because you are dealing with a lot of unknowns. Could potentially do harm to any inhabitants to the tank.

 

[Shaun Sweeney]

Thanks for the comments guys. There is anecdotal evidence from a couple of other local reefers that their aquariums really perk up when they use local ocean water but I understand their use is hit and miss depending on weather, tides and inclination. As it turns out, my system runs about 350 gallons so my water changes are significant. It also happens that getting the water is pretty easy. I'm a few minutes from a great spot that I can just drop my sump pump into and pump the water straight into the truck. From the truck, it is just a minute of work to connect to the line that goes to my two 45 gallon new water storage tanks. Bottom line is that sourcing the water is very easy. I have been filtering the water I've gotten thru a fine mesh but obviously, anything microscopic will pass thru. If pathogens are an issue, I have a seriously big UV filter that could easily be plumbed to cycle the new water before it is introduced to the tank. I like the sand filtration idea so I'll give that some thought. As to the quality of the water, we are fortunate not to have any industrial outlets anywhere near us and our large tides do a pretty good job of flushing Georgia Strait twice daily. One more note; when I add the missing salt (using Red Sea Coral Pro) all the parameters come into line. I found that interesting. I have a 140 gallon tank that has been up for about 4 years and since it will be torn down shortly (and moved to the new 140) I'm going to gradually move it over to local ocean water and watch it carefully. I'll keep you posted.

 

[Shaun Sweeney]

And I should have mentioned ... I say Vancouver ISLAND and people seem to hear Vancouver. There is a huge difference in the water quality between the two.

 

[cmcimino]

I would definitely run the UV filter on it. If you live in a place with little to no industry then you should be okay, especially if the straight has large tides. Also if others locally have had success then that's what really matters!

 

[mountainstatereefer]

I would go ahead and use the water if it were me. You can't argue with results from other local reefers... if their tank perks up and hasn't had any issues from using the seawater... then why not use it as well? Your UV filter is a great idea and would add that extra piece of mind.

Just like anything else... watch your corals... they will tell you more than you think...

 

[redfishbluefish]

I wouldn't be overly concerned. It's a relatively common practice in Florida. I know of one maintenance company that has a tanker truck that goes out to the end of a pier and throws lines into the water to fill the truck. They then use this water to do water changes on their commercial accounts.

Just make sure you heat the water before checking salinity and doing your adjustments. You'll be fine.

 

[tj w]

Shaun, I think you'll be fine using it. Especially if you're filtering and running through UV before use. I definitely would if I had that resource.

 

[Shaun Sweeney]

I tracked down a local reefer today and he has been using straight local ocean water for the past 6 months with no ill effects on his tank. His only filtration is a couple of socks that he runs the water thru. Another interesting point ... he doesn't even bother to heat the water, just drops it in and he is doing about a 20% water change each time. I think I'm off to the races.

 

[mountainstatereefer]

I would be sure to temp and salinity match the water. He may have no ill effects but he is causing undue stress each time he does this, unless he constantly runs his tank at .20 salinity and a temp that the water just happens to be at upon change.... which I find hard to believe.

On another note, as water moves in and out of a reef, one would think that there has to be lower temp pockets of water that come in and go out, much like when swimming... you find pockets of temperate water, pockets of cold, etc. Maybe this is why no ill effects have occurred in his tank? I don't know, just a thought, sounds like a topic for a whole new thread though.

Now you see how my mind works at midnight after working 12 hour shifts. Wow... I better get to bed. LOL

 

[Shaun Sweeney]

I agree with you regarding the temp. No point in tempting fate any more than I have to. He brings the salinity up and I suspect that his water warms somewhat to room temp before he dumps it in. I was thinking the same thing you were about temp variations on a real reef. I done a lot of diving and there is always a thermocline Just a question of what level. Turns out there are a few others who have been doing the same thing but I haven't spoken to them. My old tank will get a shot of ocean water in the next few days so I'll update this thread if anything interesting happens. Thanks for the comments. Seems you mind works better than mine would after a 12 hours shift. I tried working for a living but I can't say I recommend it...

 

[Shaun Sweeney]

Did a "local ocean water only" water change today and both my wife and I noticed how clear the water became but in particular, it looked like the fish were happier than usual. They seemed to be exploring parts of the tank they hadn't recently looked into. Very subjective but I'm on my way.

Meanwhile, I ran up the new 140 and sump with 100% ocean water and started cycling all the rock.

 

[Cory]

Dont use it, nothing lives in the sea

 

[Shaun Sweeney]

Funny, funny man ... Too late, I'm already using it.

 

[Cory]

Awesome, wish i lived near the sea. No issues then

 

[Shaun Sweeney]

Nope. All is well. I've done a few major water changes to the existing tank with no visible or testable changes. And ... I have a natural sump to draw the ocean water from. A perfect little hole in the rock and the sock that I pump the water thru has hardly any debris after pumping about 150 gallons yesterday. I find it interesting that after bringing the salinity up from .020 to .026, all of the other parameters come into line.

 

[Cory]

Nope. All is well. I've done a few major water changes to the existing tank with no visible or testable changes. And ... I have a natural sump to draw the ocean water from. A perfect little hole in the rock and the sock that I pump the water thru has hardly any debris after pumping about 150 gallons yesterday. I find it interesting that after bringing the salinity up from .020 to .026, all of the other parameters come into line.

Yeah thats what I expected

Salinity is a measure of different salts basically so it makes sense at 1.026 its saltier basically. Is do what your doing in a heartbeat. Seawater is pretty clean.

 

[Shaun Sweeney]

Wonder if you have any suggestions on cycling a tank. I've never done it. My first tank was just a move from a guy getting out of the hobby.

 

[Cory]

Wonder if you have any suggestions on cycling a tank. I've never done it. My first tank was just a move from a guy getting out of the hobby.

Yes there are 4 ways i know of. Bacteria in a bottle instant cycle. Live rock that has it on it. Food that rots. Ammonia in a bottle. Of them all, i like live rock.