What would be cheaper?

[Cory]

imagine a system that did 50% water changes per day to maintain all parameters. No test kits required. No auto dosers. No skimmer. No worrying about alk, magnesium, calcium, ammonia, po4/silicate.

This system has a large resevoir of saltwater above it. Its just flowing into the tank all day. But instead of going to a sump this sytems overflow drain, goes to the sewer, instead of a sump. So technically if you put a lid on it amd made the salinity slightly lower than the tanks it should stay nearly constant for a year or so. No fresh top up required.

Now imagine a system that you gotta buy test kits, triton tests for uncertainties of test kits and other impurities, salt for 10% weekly chnages, gfo to reduce po4. Plus you need an auto doser for alk and calcium, and a protein skimmer for dissolved organics. Carbon to remove yellowing in the water. Maybe buy the new turf algae filter because gfo just wont stop hair algae or cyano. Its got A sump to grow macroalgae. Then your Protein skimmer pump breaks, and you gotta buy a new one. Maybe it cost 150$. Get an Apex to control all the other stuff.

But all this could be avoided with just 50% water changes a day. You think? Maybe its the same cost but better to do 50% water changes a day.

 

[Denali08]

Interesting concept. Would like to see monthly cost to do this.

 

[Cory]

In my little tank (20 gallons), i have soent on Skimmers that totalled 500$, avast marine auto top off 225$, salt cost me about 100$ in its lifetime. 75$ in gfo for its lifetime, salifert test kits totalling 150$ in its lifetime, i bought a diatom filter to clean detritus for 180$, filter socks and a bracket for 50$, calcium chloride and magnesium sulphate and magnesium chloride for 70$, baking soda (alk) for like 6$. a diy sump/algae turf scrubber for 150$. A diy detritus settlement tank for 50$. Hanna po4 and alk checker 110$. New reagents for them 45$.

So it cost me 1711$ in one year. Not including cost of water and ro/di replacments.

Now if i just had tank, pumps, light and a heater, and had a continuous water change going it would have been just salt and water cost.

Salt where i live is 80$ a bucket of reef crystal (canada). That does 160 gallons of water. So 50% per day is only 10 gallons a day. So thats 16 days worth of salt for my little 20 gallon. So basically a month of 50% daily water changes will cost me 160$ not including the cost of water or ro/di filter replacements. I could even use cheaper salt and cut that to 110$ a month for salt for just io.

It would cost 1912$ a year in salt for a 20 gallon with io reef crystals. 1320$ a year for io. So i could have saved if i chose cheap salt it seems.

But in the end, whats better?

 

[ngvu1]

Something is off with the assumption and the math...If you spend over $1500 for the water part of the hobby for a 20 gallon tank then something is not right...Imagine the guy with a 100 gallon tank!

 

[cmcoker]

In my little tank (20 gallons), i have soent on Skimmers that totalled 500$, avast marine auto top off 225$, salt cost me about 100$ in its lifetime. 75$ in gfo for its lifetime, salifert test kits totalling 150$ in its lifetime, i bought a diatom filter to clean detritus for 180$, filter socks and a bracket for 50$, calcium chloride and magnesium sulphate and magnesium chloride for 70$, baking soda (alk) for like 6$. a diy sump/algae turf scrubber for 150$. A diy detritus settlement tank for 50$. Hanna po4 and alk checker 110$. New reagents for them 45$.

So it cost me 1711$ in one year. Not including cost of water and ro/di replacments.

Now if i just had tank, pumps, light and a heater, and had a continuous water change going it would have been just salt and water cost.

Salt where i live is 80$ a bucket of reef crystal (canada). That does 160 gallons of water. So 50% per day is only 10 gallons a day. So thats 16 days worth of salt for my little 20 gallon. So basically a month of 50% daily water changes will cost me 160$ not including the cost of water or ro/di filter replacements. I could even use cheaper salt and cut that to 110$ a month for salt for just io.

It would cost 1912$ a year in salt for a 20 gallon with io reef crystals. 1320$ a year for io. So i could have saved if i chose cheap salt it seems.

But in the end, whats better?

But may of the costs you listed are not recurring..

 

[Cory]

Yeah its not cost effective for big tanks. But on small tanks it could be practical. My maths pretty crude, just a guesstimate.

I could even go as low as 20% daily, just depends on alk and cal depletion.

 

[Cory]

But may of the costs you listed are not recurring..

True, but theres always an upgrade for me that costs me. So its probably cheaper as long as equipment doesnt fail, or i dont upgrade anything in anticipation that my reef will get better.

Big daiky water changes eliminates a lot of uncertainties for me.

 

[Ebone]

interesting concept... I have an unlimited supply of purified NSW from a research facility and I still have to modify salinity on the season... I feel like I would have more $$ in many years modding salinity then doing less water changes

 

[Cory]

interesting concept... I have an unlimited supply of purified NSW from a research facility and I still have to modify salinity on the season... I feel like I would have more $$ in many years modding salinity then doing less water changes

Id definitely be doing that!

 

[Ebone]

Id definitely be doing that!

it really is a win win for me haha... wish everyone had the availability

 

[ngvu1]

There was a guy connecting his tank with the Ocean....He never does water change and the tank looks great...But the rest of us is still bending over to mix salt and do water change....It is part of the fun.

 

[Cory]

There was a guy connecting his tank with the Ocean....He never does water change and the tank looks great...But the rest of us is still bending over to mix salt and do water change....It is part of the fun.

My dream since i was 14 years old. Water changes suck for sure

 

[Luna]

What if u use a drip system like when acclimating, 1 drips new saltwater in while 1 drips old saltwater out..

 

[Cory]

What if u use a drip system like when acclimating, 1 drips new saltwater in while 1 drips old saltwater out..

That could work, just make sure you see the tank every day that it doesnt overflow!

 

[PatW]

If you look at a normal larger tank, say a 180 gallon which is about as big as common production tanks get, the dynamics change. You need 90 gallons per day but let us say 100 gallons per day. That comes to 36500 gallons. Salt comes in 200 gallon packages. You need about 180 of them... say 200. So at $50 each, you have $9000 per year in salt. You would also need a huge RODI system. I have not priced out the cost of RODI water but it is not zero. I think my costs are about $.10 per gallon in consumables .... filter replacements and resin. Even at that price, you are talking nearly $4000 per year for the RODI water alone. So you hit about $13,000 per year for the water changes. The situation gets even more pronounced for a really big system like a 600 gallon. There you are talking $40,000 per year.

Certainly I large tank costs more for GFO, calcium supplements, alkalinity supplements and trace minerals. You also need bigger skimmers, more pumps, larger pumps and so on. But the auto top off is the same as are the test kits. But running a large tank consumes only a few hundred dollars in Alk, Ca, and Mg per year and the same for test kits. You have the initial outlay for the controller, dosing pumps, skimmer, refugium, auto top off and so on but they last years.

Arguably, large water changes make sense in maintaining tanks of less than 50 gallons. If you notice a problem, do two big water changes and problem gone. Heck, on small tanks, doing 100 percent per week routinely looks tempting from an economic point of view.

On big systems, the cost of the salt water, will eat you alive if that is all you rely on.

 

[Cory]

If you look at a normal larger tank, say a 180 gallon which is about as big as common production tanks get, the dynamics change. You need 90 gallons per day but let us say 100 gallons per day. That comes to 36500 gallons. Salt comes in 200 gallon packages. You need about 180 of them... say 200. So at $50 each, you have $9000 per year in salt. You would also need a huge RODI system. I have not priced out the cost of RODI water but it is not zero. I think my costs are about $.10 per gallon in consumables .... filter replacements and resin. Even at that price, you are talking nearly $4000 per year for the RODI water alone. So you hit about $13,000 per year for the water changes. The situation gets even more pronounced for a really big system like a 600 gallon. There you are talking $40,000 per year.

Certainly I large tank costs more for GFO, calcium supplements, alkalinity supplements and trace minerals. You also need bigger skimmers, more pumps, larger pumps and so on. But the auto top off is the same as are the test kits. But running a large tank consumes only a few hundred dollars in Alk, Ca, and Mg per year and the same for test kits. You have the initial outlay for the controller, dosing pumps, skimmer, refugium, auto top off and so on but they last years.

Arguably, large water changes make sense in maintaining tanks of less than 50 gallons. If you notice a problem, do two big water changes and problem gone. Heck, on small tanks, doing 100 percent per week routinely looks tempting from an economic point of view.

On big systems, the cost of the salt water, will eat you alive if that is all you rely on.

Yeah that's definitely not a viable choice in large reef aquaria. Unless your rich!

50% per day is mainly based on alkalinity and calcium decrease. So you could get away with 10% per day on say a softies tank in a large reef tank. But whats the point then? Lol