Water changes- What is your method?

[erin10885]

We've been having a phosphate issue in the tank at home so we've been doing weekly water changes. My hubby has a nice setup in the garage with a 250 gallon tank of salt water with a pump to cycle it and pump it out. We connect the hose to the sump, open the valve, open another valve and the tank drains, then close both valves, hook the other end of the hose to the pump, open the sump valve and it refills the tank. It takes less than 30 mins to do a water change of about 100 gallons. For my work tank, I have a pump that I stick in the tank and fill a 5 gallon bucket, then put the pump in the fresh salt 5 gallon bucket and pump it back in, water change complete

 

[PhishMonger84]

for those auto change systems, did you build it, pay someone to build, buy a turnkey solution?

I have a RODI system but have never set it up, i have a 55gal roughneck trashcan to use with it but the process seems daunting. I'm typically someone who DIYs a lot of stuff, fixes their own equipment and modifies as needed but with water i've been hesitant.

 

[707Nick]

I change roughly 4 gallons a day monday through friday doing AWCs and do a manual water change of 15 gallons at the end of each week (to clean equipment and siphon up any detritus).

What size is your tank ?

 

[FishTruck]

I run a home made dialysis system for a 1400 gallon system. I lose enough salt to require one bag of IO per week put back in the system. Basically, a stenner dual head pump (like you would use for an AWC). One for tank water that goes through the blood line on the diaysis membrane and back into the tank... the other one delivers RO water across the membrane and then down the drain.

So, this does the equivalent of a 50 gallon to 100 gallon water change weekly - 7 to 14% per day - broken up into three sessions per day.

I can bypass the membrane and swap some plumbing... and the system becomes a regular AWC - if I want to do it that way.... it's a pretty similar setup.

This does beans (nothing) to control phosphate - so I am using LC for that. My trace elements though are spot on... and I have been able to avoid water change disasters and maintain a very stable salinity. Nitrates are stable at about 20. Because it is automated and only requires me to dump in a bag of salt once per week (into the brine container), it is super easy and less work even than an AWC system.

I siphon up the detritus weekly into the filter socks in the basement.

 

[00W]

10 gallons every Monday morning. Have to put the landscape back together from my trigger so it's a win/win.

 

[Clownreef]

I dont do any water changes. I skim, have an algae scrubber, bio pellets, carbon dose and do the moonshiners method. My water is crystal clear (UV and ozone).

 

[helmsreef]

5 gallons nightly through apex awc, I was always bad about remembering my water changes so once I did the AWC its been a huge difference

 

[tmRoth]

I utilize a water storage system and do daily water changes of 1-2 gallons.

I'm going to try this. What percentage of your tank volume is this? Doing just one or two gallons a day sounds much less daunting than large weekly changes. I'm more consistent when I do small tasks daily than I am on doing large tasks less frequently.

I have a 90-gallon tank (plus sump) and my goal is always to change 10 gallons/week, but it often stretches to every two weeks and sometimes a month has gone by before I get around to it. I put it off because it's a tedious job - siphon into 5-gallon buckets, wheel my Brute can into the living room where the tank is, hook up the submersible pump and refill the tank, then clean up the inevitable mess I've made.

 

[Joe.D]

95 gallon total system volume - 10 gallon change weekly. Fill 5 gallon bucket with siphon twice dump in toilet. Do same with saltwater using small pump. Easy peasy.

 

[vetteguy53081]

I'm going to try this. What percentage of your tank volume is this? Doing just one or two gallons a day sounds much less daunting than large weekly changes. I'm more consistent when I do small tasks daily than I am on doing large tasks less frequently.

I have a 90-gallon tank (plus sump) and my goal is always to change 10 gallons/week, but it often stretches to every two weeks and sometimes a month has gone by before I get around to it. I put it off because it's a tedious job - siphon into 5-gallon buckets, wheel my Brute can into the living room where the tank is, hook up the submersible pump and refill the tank, then clean up the inevitable mess I've made.

2 gals per day on a 400 gal tank

 

[Reefer Matt]

I change according to nitrate levels. Usually two weeks to a month, ~40% for each tank. Around 150 gallons a month total.

 

[Waters]

What size is your tank ?

105G with a 25G sump. I believe in aggressive water changes.

 

[homer1475]

Weekly 20G WC's on an 85G system.

I simply press a button on my apex display to turn off equipment, and turn on a pump in my sump. Turn a valve to pump out old water to my sewer, turn another valve and press a button to turn on the remote pump to pump new water into the sump.

Suppose I could automate it, but the small amount of time it takes, I can get a better look at things going on in the tank.

 

[Anemone_Fanatic]

Water changes? What are those?

 

[Randy Holmes-Farley]

I run a home made dialysis system for a 1400 gallon system. I lose enough salt to require one bag of IO per week put back in the system. Basically, a stenner dual head pump (like you would use for an AWC). One for tank water that goes through the blood line on the diaysis membrane and back into the tank... the other one delivers RO water across the membrane and then down the drain.

So, this does the equivalent of a 50 gallon to 100 gallon water change weekly - 7 to 14% per day - broken up into three sessions per day.

I can bypass the membrane and swap some plumbing... and the system becomes a regular AWC - if I want to do it that way.... it's a pretty similar setup.

This does beans (nothing) to control phosphate - so I am using LC for that. My trace elements though are spot on... and I have been able to avoid water change disasters and maintain a very stable salinity. Nitrates are stable at about 20. Because it is automated and only requires me to dump in a bag of salt once per week (into the brine container), it is super easy and less work even than an AWC system.

I siphon up the detritus weekly into the filter socks in the basement.

I'm curious why one would use a dialysis membrane in this situation. I see no potential benefit and some drawbacks.

Have you ever looked to see what is exported using this method (say, by analysis of the removed fluid)?

I have two potential concerns.

1. Whether the exported fluid has had sufficient time to fully equilibrate ions across the membrane.

2. Whether large molecules (organics such as proteins and associated bound metals and other ions ) can be exported through the membrane.

Thanks for any insight in choosing this method.

 

[Randy Holmes-Farley]

for those auto change systems, did you build it, pay someone to build, buy a turnkey solution?

I have a RODI system but have never set it up, i have a 55gal roughneck trashcan to use with it but the process seems daunting. I'm typically someone who DIYs a lot of stuff, fixes their own equipment and modifies as needed but with water i've been hesitant.

I did a DIY, I guess, but it was just a dual head diaphragm pump on a timer.

 

[FishTruck]

I'm curious why one would use a dialysis membrane in this situation. I see no potential benefit and some drawbacks.

Have you ever looked to see what is exported using this method (say, by analysis of the removed fluid)?

I have two potential concerns.

1. Whether the exported fluid has had sufficient time to fully equilibrate ions across the membrane.

2. Whether large molecules (organics such as proteins and associated bound metals and other ions ) can be exported through the membrane.

Thanks for any insight in choosing this method.

Great questions, Randy. I feel like I was just called on in class by the professor. Gulp.

Why? Just for fun and something to talk about with other nerds. Kind of like a triple carburator on an old Ford Galaxie.

And... compared to making an awc system, the only extra cost is the dialysis membrane, and one extra pump to run the brine. This deletes the need for properly made saltwater - which saves space and effort. I do admit... I could use brine infusion instead of salt water with an AWC and omit the membrane and one pump - but I borrowed the idea from the Seavisions dialysis system - and this is where I am in my journey.

Potential benefit = for anything smaller than 400 kDA (or whatever the pore size of the membrane), there might be preferential removal of anything not in the salt mix - over time. This might include phosphate, nitrate, ammonia, any toxic metals, certain drugs, small organic toxic compounds (organophosphates for example). So maybe, for every 50 lbs. of salt I put back into the system, I can accomplish the same thing as 100 lbs. of salt consumed doing water changes - with regard to this group of dialyzable / ions and other molecules. Since my system is 1400 gallons, reducing the salt budget and how many pounds of salt I have to haul into the basement (by half for example) would a considerable accomplishment. This is the claim by the dialyseas (tm) company - seavisions - who has been selling a version of this for decades. I quote from the diayseas website "removes waste by minimizing original water and salt loss". After experiencing mysterious acropora declines over the years... any potential help in clearing out mystery poisons from the exterminator or whatever else... helps me sleep.

Here is an article outlining an analysis if the exported fluid. https://reefkeeping.com/issues/2006-04/pr/index.php
It seems to support the preferential removal of nitrate and phosphate. Hats of to Ken Feldma. Seemed to conclude a solid "maybe" that it works as advertised to preferentially remove certain ions and molecules.

Large molecules cannot be removed by dialysis. So, I do wonder... what is stuck in my tank that is not removed by dialysis, mechanical filtration, ozone, UV, metabolism (fish, invertebrate, coral, algae), carbon... or other degradation? Something that can only be removed by water change and nothing else. I do wonder!

Future experiments.
1. how does the flow rate effect equilibrium? I suppose I can run the flow at different rates, and different pressures and check the resultant product salinity - to see if there is a difference. Does the export salinity rises with slower flow rates? What about if I pause the system for an hour, then analyze the flush?
2. what is the least amount of dialysis / salt, that I can get by with while maintaining normal triton tests? right now, four bags per month (enough to make 200 gallons of salt water). Perhaps, a 15% monthly water change equivalent. not exactly a miracle - I admit.


Appreciate comments and discussion.

 

[Randy Holmes-Farley]

Potential benefit = for anything smaller than 400 kDA (or whatever the pore size of the membrane), there might be preferential removal of anything not in the salt mix - over time. This might include phosphate, nitrate, ammonia, any toxic metals, certain drugs, small organic toxic compounds (organophosphates for example). So maybe, for every 50 lbs. of salt I put back into the system, I can accomplish the same thing as 100 lbs. of salt consumed doing water changes - with regard to this group of dialyzable / ions and other molecules.

I have always thought the dialyseas is a poor system. lol

For sure I agree that small molecules will tend to equilibrate across the membrane.

Even assuming full equilibration, however, the effect is not half as much salt used. Where does that idea come from?

At full equilibration, all ions in the dialysate equal all ions in the tank water. Thus, removal of that fluid exactly matches removal of the same amount of tank water, which is what you do in a water change.

Thus, for 1 gallon of new salt water entering the dialysis tubing, you export 1 gallon of salt water that now matches the tank water. Thus, I see it is a 1:1 equivalence to a normal water change.

Why? Just for fun and something to talk about with other nerds. Kind of like a triple carburator on an old Ford Galaxie.

That's certainly a fine reason to do anything in a hobby.

 

[Hats_]

Have a 95 gallon mixed reef, only do waterchanges if i want to clean the gravel but thats very rare.

 

[FishTruck]

I'm curious why one would use a dialysis membrane in this situation. I see no potential benefit and some drawbacks.

Have you ever looked to see what is exported using this method (say, by analysis of the removed fluid)?

I have two potential concerns.

1. Whether the exported fluid has had sufficient time to fully equilibrate ions across the membrane.

2. Whether large molecules (organics such as proteins and associated bound metals and other ions ) can be exported through the membrane.

Thanks for any insight in choosing this method.

I have always thought the dialyseas is a poor system. lol

For sure I agree that small molecules will tend to equilibrate across the membrane.

Even assuming full equilibration, however, the effect is not half as much salt used. Where does that idea come from?

At full equilibration, all ions in the dialysate equal all ions in the tank water. Thus, removal of that fluid exactly matches removal of the same amount of tank water, which is what you do in a water change.

Thus, for 1 gallon of new salt water entering the dialysis tubing, you export 1 gallon of salt water that now matches the tank water. Thus, I see it is a 1:1 equivalence to a normal water change.

I got the idea from dialyseas hype. I do note that on the dialysis membrane spec sheets… different molecules diffuse at different rates…. and I am not sure if allowing equilibrium is the goal.

I have been hoping a nephrologist would chime in to explain what selective removal is and is not possible (beyond manipulation of the dialysate). Adjusting resistance on the ouflow of the ‘blood line’ greatly affects the product and waste ratio… as free water tends to diffuse really quickly into the tank.

That's certainly a fine reason to do anything in a hobby.