Learn Something New Everyday on RC

[Reverend Reefer]

you really do learn something new everyday here on RC.

yesterday i read some post about some guy using the "wet-skim method for water changes", definitely never heard this before! so after doing some research, i realized that this is why my new skimmer has this little hole drilled into the collection cup that is plugged up with a piece of plastic!!! i mean, i originally thought this was to prevent the collection cup from overflowing, which it is, but it can also be used to do this type of water changes...

1. from what i understand of this method (gonna try it today), you dial your skimmer up so that it wet-skims overflowing the collection cup on purpose.

2. you take all this scummy tea color water and have it go into your water change bucket.

3. seems like this will take a bit longer than doing the other way of doing water changes and it depends on the strength of your skimmer pump.

4. then you replace that skimmate water with new freshly made saltwater.

this is supposedly better than siphoning out water from the display (or sump) and replacing it with fresh saltwater since you're taking out DOCs at the same time using the wet-skim method of water changes.

the best argument i've read on RC for this method was, "well, if you were to start a new tank with some of your system's water, which would you use? water siphoned from your display or skimmate water from the collection cup?" so why not take the skimmate water out and replace with new water?

the only negative i've read is you have to watch your salinity and turn off your auto-top offs since the wet-skim method of doing water changes takes a lil longer so you lose a lil evap water in the process.

[kduen]

I read that post too but I believe he said he swithces his ATO water for the pre-mixed saltwater so as the Skimmed water is being depleted there is new salt water entering the system via the ATO. Thinking about trying this myself.

[Toddrtrex]

I like the idea of it -- just wouldn't work for me and my set up.
1) My skimmer doesn't have a drain hole -- though that wouldn't be too hard to fix
2) I don't have an ATO -- Though I suppose I could set up a small powerhead to refill the tank as the skimmer "worked"
3) I gravel vac my shallow sandbeds -- this is the major reason why this wouldn't work for me.

However, if you have the proper set up, I think that this would be a good idea.

[cr reef]

Todd,

I read this and the original thread and thought this might be a smart way to go. I also vacuum my gravel so, my question for you is;

How about just doing the wet skim for part of the W/C and the rest of it vacuum the gravel.

I was going to try it this weekend, just curious if you see a reason it wouldn't be more beneficial, as you and I are doing close to the same thing.

Your thoughts,
Thanks

[Toddrtrex]

That could work -- for me that would mean I would be changing out 10 gallons instead of 5 -- which would, most likely, be better for my tank. It takes me about 5 gallons to get all the sand in my 75.

So, in the end, I don't see a reason why it wouldn't work -- just make sure that your sump doesn't run dry.

[cr reef]

Thanks for the quick post, it seemed to make sense to do it this way.

I actually turn off everything but lights when I do a W/C so no worries on the sump issue, but thanks

[Toddrtrex]

Thanks for the quick post, it seemed to make sense to do it this way.

I actually turn off everything but lights when I do a W/C so no worries on the sump issue, but thanks

Sure thing.

I believe that you would need to leave the main pump running for this to really work --- otherwise you will just be removing the water from the skimmer section (( assuming an in sump skimmer )). First, that wouldn't remove that much DOCs and the skimmer section would run dry. Would need to have an inflow of water from the main tank while the skimmer is running wet.

[cr reef]

Face Slap :):)

Thanks, I would need to keep the pumps on :):)

[Chris27]

I like the idea of it too, but am a little leery of salinity fluctuation. I guess if you set up a controller to monitor some float switches and the salinity one could rest at night knowing that back breaking water changes are a thing of the past and your tank will be happy. My wife would sure be happy about it given that the Brute and 5 Gallon buckets would no longer be in her living room.....

[kduen]

He also said that since the process takes him about 12 hrs. (I think thats what he said) he mixes the saltwater to a lower salinity to acount for evap. So instead of replacing 1.026 with 1.026 it would be replacing it with like 1.024. But this really varies on the ammount of evap you will gat in 12 hrs. If the tank is big enough probably 100 gal. or more and only evaped about a gallon it probably wouldn't have too big affect.

[eja99]

Yeah, that was interesting thread. I'm thinking about doing the same thing for my new setup.

[Reverend Reefer]

so i tried it last night. i did it slightly differently from the original thread i read it from. here are some comments from my experience:

1. it worked and it took less than an hour to do a small water change (i did 4G to test it)
probably take 2 hrs to do a 10% water change

2. the wet skimmate was pretty greenish orange with some chunks. yummy. made me feel good about doing the WC using this method.

3. my sump is set up like this in order of flow direction: skimmer->fuge->return/topoff section-> T-redirect some to fuge some to DT. also note, my overflow drain is one of those siphon overflows where you can lower the drain if the DT level goes down (which i had to do to keep the return pump on and not have it run dry)

4. given my sump design, and drain, i turned off the auto-top off, but left the return pump on.

5. my skimmer seems like it could have been designed with this method in mind because it works like a charm! i used airline tubing which couldn't keep up with my skimmer dialed all the way up. i actually had to dial it down a bit to keep up with the airline drain. if i had a slightly thicker tube, i believe i could have completed the process in half the time. regardless, the hole in my collection cup was threaded so its made to put a threaded simple airline connector (like those john guest one side threaded L connectors) to it.

overall, i think this is a pretty good method. you can't really siphon clean the sand this way, but since i have a couple conchs and a goby, they keep the sand bed in the DT pretty clean anyways. i takes a bit more time, so we'll see if i can keep up doing it this way. i will likely alternate methods depending on my time but i do like it. like i said though, the dirty skimmate water makes me feel like i'm really doing what a WC should be doing, which is replacing bad water with good water. who knows if this is true, but my refractometer readings are the same as before the WC, as of this morning (1.026).

almost forgot to turn the auto-top off this morning though.