Wet Skimmate Water Changes?

[borderreef]

It's been a while since anyone chimed in on this, so I figured I would. I actually use wet skimming as a continuous water change. I've been doing this for at least 5 years, when I first set up my 45g. Now I do it in my 135g. I have fsw in my ato at about 30ppm. This compensates for both evaporation and the wet skim. I am able to keep, barring the occasionl mishap, my dt stable at 35ppm. I do it at a relatively slow pace, but still wet. I have not paid much attention to the amount of water I go through, but it is probably around 12g per week. That's about 10% weekly water change, give or take a few.

 

[borderreef]

It's been a while since anyone chimed in on this, so I figured I would. I actually use wet skimming as a continuous water change. I've been doing this for at least 5 years, when I first set up my 45g. Now I do it in my 135g. I have fsw in my ato at about 30ppm. This compensates for both evaporation and the wet skim. I am able to keep, barring the occasionl mishap, my dt stable at 35ppm. I do it at a relatively slow pace, but still wet. I have not paid much attention to the amount of water I go through, but it is probably around 5-7g per week. That's about 10-15% monthly water change, give or take a few.

 

[dastowers]

Wonderful thread. I use this technique also for my 150g reef.

 

[LouisianaReefer]

I have thought about the possibility of having 2 auto-top-off devices with prepared replacement water to do this method for automatic water changes. This may be more trouble than it is worth; however, I am curious if someone has tried this. It could lead to lots of water on the floor if not setup correctly or if an auto-top-off device fails.

 

[SantaMonica]

Any updates? Been wanting to read from the start, but for now will watch what others are doing.

 

[LouisianaReefer]

I skim wet, but the downside is ... you have to constantly check salinity, calcium,mag and DKH . I now add a mix 50/50 of sea water and rodi water to my ato container. It demands adjustment from time to time. I do check salinity almost daily though !! It works and I still do regular water changes weekly.

Wow! That is a lot of work. Still, I am sure you tank is very healthy.

I have one question about those who do only wet skimming without standard water changes. How do you get rid of detritis? I may have missed that during this thread. If this was answered prior, feel free to point me to the URL / post.

 

[jccaclimber]

I have thought about the possibility of having 2 auto-top-off devices with prepared replacement water to do this method for automatic water changes. This may be more trouble than it is worth; however, I am curious if someone has tried this. It could lead to lots of water on the floor if not setup correctly or if an auto-top-off device fails.

It seems like there should be some relatively easy way of regulating the volume of wet skimmate and pushing that same amount of water back in to the system.

Something like using the skimmate (feeding in to a plastic bag or similar) to displace water in a tank which overflows into the display system. That way your skimmate wouldn't evaporate and would return the same quantity of salt water as was removed. I don't think that would interfere much with any freshwater ATO either.

 

[Ptyochromis]

Wow! That is a lot of work. Still, I am sure you tank is very healthy.

I have one question about those who do only wet skimming without standard water changes. How do you get rid of detritis? I may have missed that during this thread. If this was answered prior, feel free to point me to the URL / post.

It's not really a lot of work. If your turn your ATO off your salinity won't change much.

Detritus gets removed from wet skimming because it doesn't have time to 'escape' the bubbles. Nonpolar molecules that normally wouldn't stick the the bubbles get pushed out the top of the skimmer.

 

[alfieferenzo84]

is anyone still fallowing this post?

I read the 13 pages i love the idea but i think people don't understand the main part

take a few days of wet skimming to do a water change then switch it back to normal witch will give you more doc water change vs just sucking off the top.

i haven't done this but i am thinking about doing it.

my question is has anyone figured out how much better this is?

say i change 30% of wet skim vs doing old fashion water change 30% is doing wet like doing a 50% or is it even higher or is it like doing 31%?

I know doing 30% wet has to be a higher volume because the water will be more concentrated. but i want to know how much more so to be sure it worth doing it all manually.

 

[lokii_37]

is anyone still fallowing this post?

I read the 13 pages i love the idea but i think people don't understand the main part

take a few days of wet skimming to do a water change then switch it back to normal witch will give you more doc water change vs just sucking off the top.

i haven't done this but i am thinking about doing it.

my question is has anyone figured out how much better this is?

say i change 30% of wet skim vs doing old fashion water change 30% is doing wet like doing a 50% or is it even higher or is it like doing 31%?

I know doing 30% wet has to be a higher volume because the water will be more concentrated. but i want to know how much more so to be sure it worth doing it all manually.

I may be wrong but I think the point is to always wet skim, as opposed to adjusting wet/dry all the time. You do have to watch your salinity because you will need to be toping off with SW.

I wet skim and about 50% of my top off is 1.026 SW

 

[dukduk]

is anyone still fallowing this post?

I read the 13 pages i love the idea but i think people don't understand the main part

take a few days of wet skimming to do a water change then switch it back to normal witch will give you more doc water change vs just sucking off the top.

i haven't done this but i am thinking about doing it.

my question is has anyone figured out how much better this is?

say i change 30% of wet skim vs doing old fashion water change 30% is doing wet like doing a 50% or is it even higher or is it like doing 31%?

I know doing 30% wet has to be a higher volume because the water will be more concentrated. but i want to know how much more so to be sure it worth doing it all manually.

i'd like to know too, i saw video from reefdvms i get the concept kinda but i dont get the chemistry it.

 

[gaberosenfield]

I read this entire thread and it seems that the only serious downside to implementing a constant automatic water change via wet skimming is that it affects your sump water level and thus your ATO, meaning you must manually make occasional adjustments to topoff water salinity or drip rate.

Then I read this post:

It seems like there should be some relatively easy way of regulating the volume of wet skimmate and pushing that same amount of water back in to the system.

Something like using the skimmate (feeding in to a plastic bag or similar) to displace water in a tank which overflows into the display system. That way your skimmate wouldn't evaporate and would return the same quantity of salt water as was removed. I don't think that would interfere much with any freshwater ATO either.

This is brilliant! Unless I am not thinking about this properly, it seems that the following system could be implemented to perform automatic continuous water changes and use a normal ATO topping off with RODI (or kalkwasser or whatever):
1) set skimmer to wet skim (say about .75% tank volume skimmed out per day).
2) set up skimmer collection cup to drain into a container that is floating in your new salt water container.
3) as the skimmed water enters the floating container, it will displace some new saltwater, raising the water level in the new saltwater container.
4) the higher water level in the new saltwater container could be set up to trigger a float switch, turning on a pump that pumps new saltwater back into the sump, returning the new saltwater container back to its initial water level.

The beauty is that this system should EXACTLY replace the amount of water removed by the skimmer, meaning that if your wet skimming removes 1 gallon of water per day, one gallon of new saltwater will be replaced per day. This should have no effect on the total sump volume, so if you lose a gallon of water per day due to evaporation, your return section should still be a gallon emptier at the end of the day, allowing you to use a normal ATO!

I am definitely going to try this on my next tank (still in the planning stages). Great idea and great thread! I hope someone reads this and gives me their thoughts

 

[Elliott]

I read this entire thread and it seems that the only serious downside to implementing a constant automatic water change via wet skimming is that it affects your sump water level and thus your ATO, meaning you must manually make occasional adjustments to topoff water salinity or drip rate.

Then I read this post:


This is brilliant! Unless I am not thinking about this properly, it seems that the following system could be implemented to perform automatic continuous water changes and use a normal ATO topping off with RODI (or kalkwasser or whatever):
1) set skimmer to wet skim (say about .75% tank volume skimmed out per day).
2) set up skimmer collection cup to drain into a container that is floating in your new salt water container.
3) as the skimmed water enters the floating container, it will displace some new saltwater, raising the water level in the new saltwater container.
4) the higher water level in the new saltwater container could be set up to trigger a float switch, turning on a pump that pumps new saltwater back into the sump, returning the new saltwater container back to its initial water level.

The beauty is that this system should EXACTLY replace the amount of water removed by the skimmer, meaning that if your wet skimming removes 1 gallon of water per day, one gallon of new saltwater will be replaced per day. This should have no effect on the total sump volume, so if you lose a gallon of water per day due to evaporation, your return section should still be a gallon emptier at the end of the day, allowing you to use a normal ATO!

I am definitely going to try this on my next tank (still in the planning stages). Great idea and great thread! I hope someone reads this and gives me their thoughts

1. The skimmer would need to be placed above the fresh seawater reservoir to be able to drain it's skimmate into the floating container, otherwise skimmate would need to be pumped there. Skimmate tends to clog over time.

2. The floating container would need to be inspected and emptied regularly and would be another chore

3. If for any reason it leaked one would be adding skimmate directly to the freshwater reservoir.

I think it's a clever idea however since the current system is working fine I personally would not go this route

 

[jccaclimber]

I actually had the skimmate container floating in the salt water when I came up with that. I figured the skimmate container would need to be manually emptied and saltwater replaced at that time. A small auto water change could cover for this. Thinking about it more, putting the skimmate container in a second ATO that has salt water would do the same thing. I can draw it up if anyone wants me to. Seeing as my salt tank is currently a 14 gallon biocube I won't be implementing this any time soon on my own setup.

 

[gaberosenfield]

jccaclimber: I meant that the skimmate container should be floating in a reservoir of new saltwater while the freshwater reservoir is hooked up to a normal ATO system.

I realize of course that the skimmate chamber would need to be emptied, but if I size the reservoirs correctly, I would only need to empty the skimmate chamber and refill the saltwater reservoir about once a month at the same time, making maintenance pretty easy.

Elliot: I realize that the skimmer cup would have to be above the skimmate reservoir for this to work. I thought about using a pump to push the skimmate into the reservoir, but was worried about clogging... I'm glad your system is working flawlessly for you, and clearly it can be made to work by simply estimating your evap rate and dripping in freshwater. I just want the peace of mind that comes with knowing that I am not allowing my salinity to change based upon fluctuations in my evap rate between measurements and adjustments. After all, that is the whole point of an ATO.

I would try it out now, but don't have a reef tank set up ATM Thanks for your thoughts guys and for responding so quickly to such an old thread!

 

[swcc]

in nature salinity varies... soo... no needs to freak about it... it varies and in accordance you replace water to make it up... easy.

 

[gaberosenfield]

Good point. I probably shouldn't over-complicate things more than I need to. I tend to get excited about the technical components of this hobby, but maybe it is more natural/healthy for corals to experience mild salinity fluctuations. Thanks for the advice and ideas. This is why I come here.

 

[wwu123]

Rather than having a floating container, why not have end of the skimmate overflow tube tied to an empty plastic bag in the freshwater container? That way the bag will expand at the same volume and the freshwater is depleted.

If it worked perfectly, at the end the bag would be expanded with skimmmate to line the freshwater container, and does not even need to support the weight of the water if you can carry the entire container to dump out the contents. This is assuming your container is relatively small - my two freshwater reservoirs are ~2-2.5 gallon plastic pet food containers.

 

[gaberosenfield]

1. I do not want to replace skimmed out water with freshwater; the skimmate is saltwater so it should be replaced with saltwater.

2. I would have trouble trusting a bag to hold the skimmate. How would you ensure the bag will stay sealed when it is being filled with skimmate? What about what happens when it is full? How could a failsafe be built in to prevent an overflow?

 

[lokii_37]

I think this is an awesome idea. Your SW topoff tank could a very short tank. If it were 6"x24"x48" that would hold about 30g. It could lay flat on the floor of a fish room. Put a bladder connected to the skimmer cup in the tank and your good to go.

I think emptying 30g of skimmate would be pretty nasty thou.