So about 3 months ago I decided to try out a new approach my brother has been working on with his 210.

First let me give you a break down of the tank then what exactly im doing.
150gallon tank
40 gallon refugium
40 watt UV sterilizer

Stock List:
Fish:
2 mated true perc
maroon clown
yellow tang
sailfin tang
kole tang
4 damsels
bi-color angel
coral beauty
3 scooter blennys

inverts:
purple lobster
coral banded shrimp
condy anemone
maxima clam
croecea clam
2 pencil urchins
blue linckia
orange linckia
30-40 assorted hermits
40-50 assorted snails

corals:
large mushroom colony
kenya tree
star astria
digitatus
green slimer
cup
devils hand



Now here was the plan:
I nottice i need to replace almost 2 gallons of evaporated water each week. (which sounds a bit high to me) but the top of the tank sits under 800 watts of 20,000K so i guess a lot of evap. is expected.

Any who i've got 340 lbs or live rock and the sump has enough macro-algea to fill a dump truck. I got tired of keeping to have to fill a bucket with RO and re-fill the sump.

I set up an auto-top off and aqua doser. high flow.

At first using this system seemed scary to me and i did lose a clown fish, however i don't believe it had anything to do with the tank. There was a small nitrate spike at week 6 however it was taken care of in about 3 days. I have tested water params every 3 days since this experiement has started. At first the water params at the point of what would have been my water change started to go a little bit off, i did nothing and they took care of themselves. my water quality has not gone off the mark in about a month now.

I will let you guys know when exactly my water params do take an actual turn. Also believe it or not there is alot less algae then i had first expected. the snails and urchins seem to be taking care of the algea issue. and the high flow seems to keep anything from really STICKING.

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So basically you're using a tank with a macro filled refugium and not conducting water changes. With nitrates and phosphates remaining low.

Hummmmmmmmmmmmmmmmmmmmmmmm

Congratues.

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

I see it as the water changes are happening via the ro/di exchange. The water quality and algea is kept in check by the inverts and the high flow.

first for you here are my tests results after 3 months of no water changes.

(also let me add i over feed my fish.)

Salinity/specific gravity:
1.025

pH:
8.3

Ammonia/Nitrite:
0

Nitrate:
0

Phosphate:
0

Calcium:
500 ppm

Alkalinity:
11 dKH

Magnesium:
1200 ppm

Strontium:
6-8 ppm


That's 3 months of no water changes, over feeding, medium-large bio load.

also i do not use a protein skimmer or anything like that. Just a UV sterilizer, refugium filled with macro algae and the best filtration: a bunch of live rock.

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Ro/DI on the top off may be required for corals. The idea is that the macro algaes filter out toxins like heavy metals as they consume nutrients. But limiting those metals put into the tank is also a good idea.

I don't know what level magnesium started at but I have noticed that magneisum does tend to drop as time goes on. Along with calcium and carbonate (alk) also. So you will probably have to start dosing the diy 2 part system or drip kalk. But then you have to do that even with water changes anyway.

Keep us posted and congratues.

my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

i'm actually in the middle of setting up a DIY drip kalk system similar to this one:

A Simple DIY Kalk Dripper by Agu Lukk - Reefkeeping.com

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Topping off water in place of water changes isn't quite a true water change. When water evaporates, a majority of what evaporates is just plain old water. when you physically change water, you remove nitrates, ammonia, etc. (which is much more efficient) If you can keep your params in check this way, awesome, but if you notice a decrease in water quality, you may wan't to buck up and change some water in that monster tank. Have you looked into a RO/DI unit? This will save you time/money.

We know replacing evaporative water is not a water change.

so lets analyze just exactly what a system of water changes do.

assume:

1) the replacement water has 0 of something

2) That something is increasing at 1 per day.

3) That somemthing is measured as a linear concentration (unlike pH which is not linear). Like Parts per million.

4) and you are do water changes as some interval with the amount of change tied to that interval. 10%/every 10 days, 20% every 20 days, etc.


Where does the tank wind you when this schedule has been running long enough that we can no longer measure and difference just before any of the water changes?


Answer 100 times the daily increase under any of the water change schedules.

The formula is:

just before water change=(daily increase*days between water changes)/(1/fraction of water change) + whatever is in the replacement water.


Addiitionally the macro algaes consuming nitrates also returns oxygen and consumes carbon dioxide. Plus that process also returns carbonates consumed by the aerobic bacteria reducing the ammonia/nitrItes.

We see this in new tanks where after a few months newbies are shocked they have 60-160ppm nitrates and are extremely fustrated because they have done their water changes.

While you may have extreme emergencies with very high ammonia values where water changes are a good idea, those are extremely rare. I had one 3 years ago where I inadvertantly added a toxin that pegged ammonia to very high values in a matter of hours. And I lost one fish. What I did was get the fish out of the tank, dosed prime, and let the tank heal itself. Ammonia finally dropped down a week later when I rinsed my filter media. I presume that removed the toxin.

But that was the one time oppsies not normal operation. Under normal operation just get the macros in there and let them expand and condition the system. Just as this poster has realized, the tank will basically take care of itself.

And IME for years.

my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

well everything seems to be going great all the coral and fish are thriving, here is the weird part: my nitrate slowly rose to over 160ppm+ i actually cant even get an accurate reading with my test kit.

Seeing as how everything is literally flourishing and i have almost 0 algae growth in the display tank and my macro algae in my sump is basically out of control i'm not too worried about it. everything else is exactly where it needs to be.


However if i ever chose to add another fish what is going to happen if the fish is put into a tank with off the charts nitrate?

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Does "no watter" mean you don't have any lights on the tank?

wow I want to see what happens with this.....

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what ever works for you is the way to go!!!!!!!!!

FWIW I had nitrates of 120-160ppm with the api nitrates test kit.

I added an in tank refugium which is just the back 3" of the entire tank and added some caulerpa profilera and grape caulerpa. I also added 2 2 tube 4' utility fixtures behind the tank point forward to light up that refugium. With the extra lighting the grape took off and out competed the profilera. and nitrates droped to unmeasureable levels in 3 weeks.

So I think with a larger refugium the nitrates will drop down.

After the nitrates drop down you may start getting some cyano (red slime).

At that point I kill the lights for a few days to kill off the cyano and rebalance the tank. Killing the cyano will return nitrates to the system. Cyano can get nitrogen from nitorgen gas in the water. So you wind up converting nitrogen gas to nitrates which in turn feeds the macros to rebalance the system.

Keep us posted.


I presume phosphates are still unmeasureable.


my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

I have seen systems like yours with denitrate filters on them, and the nitrates still can't be kept in check. The only way I see to get those nitrates down is to do massive water changes. Even if you could keep enough macro algae to keep the nitrates down, you'll never be able to keep up with the other water parameters. New salt will add all the trace elements, calcium, iron and magnesium that you need. I think that by not doing water changes you may be making more work for yourself. PS I do 30-50% water changes on most of my reef tanks 1-4 times a month, and I really don't have to add anything other then some Iodine.

Well doing a water change would ruin my whole idea. I have a doser that runs all my chems i need in their.

I figure if the high nitrite isnt causing an actual problem (which as of right now there is no issue) then i'm going to leave it be for the time being.

Just as an up-date i bought another MAXIMA and put him in there with my Crocea and he seems to be doing great so far. its been about 2 weeks and he looks as healthy as a horse and is alert as can be.

I'll let you guys see some pics hopefully by friday.

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160ppm is going to be harmful to the more sensitive animals in your system. The effects will be long term and chronic, there are rarely acute diseases associated with Nitrates.

How much macro algae are you harvesting from your refugium? This is an indication of how much Nitrate is being removed. If your Nitrates are so high you will need to find a way to increase the macroalgae output. Macro algae of typically limited by temperature, nutrients, and light. In your system you may actually have to add phosphate to receive the nitrate removal you need if you're going to rely on macroalgae for Nitrate export.

I remove approx a 1gal zip lock worth every 2-3 weeks.

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With that growth I am positive you simply need to let the macros expand until nitrates drop down. Once you reach that point nitrates will drop down very rapidily. With significant daily drops.

One poster noticed that all the sudden nitrates were 0. He was so surprised that he measured them 3 times to make sure.

fortunately once that point is reached it just seems to be so easy to keep nitrates at 0.

But then cyano can show up after that.

my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

so i should stop pruning until i reach 0?

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Yep. If there is enough room for the "extra" that is. Otherwise you need a bigger refugium.

my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

i'll give it a shot

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What's the turnover rate through the refugium? How much light? How much area in the supm is dedicated to the refugium?