Large water changes input

[sirruckus]

Tested my tank water recently, since this is something I've often neglected - and finally got most of the parameters inline except Nitrate (just did a 20% water change last week).

After searching the internet and other reputable forums water changes are the solution. Right now I have 80-160 ppm Nitrate which caught me by surprise - but it all makes sense now since two of my fish have disappeared in the last 10 days (cant find them, even after moving rocks, anemone likely cleaned up).

Large water changes are frowned upon, is this because most people are scared, and don't have experience and just carry on the myth? One article suggest draining tank down to 20% water - then filling up to 40% , then drain that down to 20% again, then fill back up. This theoretically would change my Nitrate from 160 down to 16ppm.

Anyone else had to resort to this? If it was an option - I'm concerned about corals being above surface water.

Look forward to your comments

[monocus]

why not do 10 % water changes every day for the next few days or twice a day.as for nitrates build a nitrate reactor

[xenon]

Water changes are not the most cost effective solution for high nitrates unless you have a nano.

What size tank do you have?

I would consider carbon dosing to lower nitrates if you have a good size tank and skimmer that is oversized.

[sirruckus]

this is a 90 gallon tank

the problem with 10% water changes, it would take 22 consecutive days to get Nitrates from 160 down to 16 (theoretically) provided nothing else impacts the levels

[Parker]

this is a 90 gallon tank

the problem with 10% water changes, it would take 22 consecutive days to get Nitrates from 160 down to 16 (theoretically) provided nothing else impacts the levels

That's assuming your nitrates don't continue to climb / increase along the way via heavy feeding etc.

The first course of action would be to find out what's causing your high nitrates and then come up with a solution and path forward. You don't necessarily want to drop your nitrates that far that fast, nothing good happens fast.

[subman]

As important as water changes are...they are not a great way to reduce nitrates. there are many ways to reduce nitrates as mentioned above but i think you also need to find the cause of the nitrates. perhaps the two dead fish caused the spike or maybe the deaths were caused by the high nitrates. change some water and look into one of the nitrate reducing methods.

[waynemah]

You don't necessarily want to drop your nitrates that far that fast, nothing good happens fast.

Since it's to the point where there are casualties, it might be a good idea to try and reduce the nitrates fairly quick.

I would perform a 20% water change every 2 days until the nitrates are in check. During this time look for the cause of the nitrates and look into a long term solution for the nitrates.

If you want some solutions, it might be a good idea to post some details about your setup / husbandry.

[sirruckus]

90 gallon reef tank with one corner overflow & opposite side return, (2) 950 gph powerheads. Estimate 75lbs Live rock with fine sand bed.

-estimate 30 gallon multi chamber sump with:
-Marineland Pro 300 skimmer first chamber with return line - no filter sock
-one free chamber with heater and sensors
-Sedra 7000 return pump in last chamber with nano sized powerhead to keep circulation in sump & ehiem canister filter acting as a reactor filled with the red ceramic balls, introduced this when trying to seed zeobak

P.H. around 8.2
Temprature 80.5-81.5
Magnesium 1100ppm-1300ppm

I'll get my other readings when I'm at home tonight

[Parker]

Since it's to the point where there are casualties, it might be a good idea to try and reduce the nitrates fairly quick.

I would perform a 20% water change every 2 days until the nitrates are in check. During this time look for the cause of the nitrates and look into a long term solution for the nitrates.



Agreed, I only meant for a very large water change, 80% etc.

If the fish are already stressed from the high nitrates, adding in the stress of acclimation to a very large water change isn't the best option, unless you have no choice. In which case, you do what you have too.

[Aquattro]

I would have no concerns doing a 80% water change. Just be sure it's very close to the existing water in all parameters you can measure. Temp, pH, Ca, etc..And don't use a different salt :)

[ocean diver]

How often do you clean your canister filter?

[sirruckus]

actually I haven't cleaned the canister filter - all sponge material etc. has been removed, only the ceramic balls are inside.

[sumpfinfishe]

IMO i would do five 20% changes every other day that would give your
setup a good flushing

[Duker]

Since it's to the point where there are casualties, it might be a good idea to try and reduce the nitrates fairly quick.

I would perform a 20% water change every 2 days until the nitrates are in check.

Yup, I agree do two consecutive 20% water changes a week for the next month or until nitrates are in check, reduce the amount of food if it's crazy amounts, and I would also suggest getting yourself a phosban reactor and use some bio-pellets. I had very high nitrates then I put a bio pellet reactor on with the CORRECT sized pump for bio pellets and they went from 50-5ppm over 2 months. I now never have nitrates over 2ppm. Good luck.

[kien]

if done carefully (similar parameters as Aquattro suggested) a larger water change (50-80%) should go just fine. This is how I have done tank transfers in the past. Fill new tank 20% with old tank water then the rest with new water. As others have said, you don't want to be doing this on a frequent basis, but for a one or two off event for quick and short term correction purposes larger water changes are fine. A few weeks ago I did two consecutive 50% water changes in my tank to help flush out a treatment that I did on my tank.

[waynemah]

actually I haven't cleaned the canister filter - all sponge material etc. has been removed, only the ceramic balls are inside.

The Ceramic balls might be the cause of your nitrates... If you have room in your sump, you might want to consider sourcing a zeovit reactor, use the zeo media and go on the base system (Start, Bak, Food). It's a fairly proven system and well supported.

[Aquattro]

Not sure what the concern is on water changes. Where does this common 20% come from? Not sure how too much clean water is going to hurt your fish, given that the important parameters match.

[sirruckus]

I appreciate your guy's input on this topic - lots already!

I understand the worry people have with such a large water change, and I agree it should be avoided as best as possible. I can't say that I've done one, and most people probably cant (even those who advocate not to do one) - because it gets into an uncomfortable zone.

But one analogy I heard from someone that was successful:

consider yourself as the fish - trapped in a garage with a car running, filling up with exhaust (Phosphate levels) - opening up the garage door to let everyone out as fast as possible may shock you, but is going clean the air and.

simply - each has its benefit and each has its downfall.

[sirruckus]

Yup, I agree do two consecutive 20% water changes a week for the next month or until nitrates are in check, reduce the amount of food if it's crazy amounts, and I would also suggest getting yourself a phosban reactor and use some bio-pellets. I had very high nitrates then I put a bio pellet reactor on with the CORRECT sized pump for bio pellets and they went from 50-5ppm over 2 months. I now never have nitrates over 2ppm. Good luck.

that's reassuring to hear - just picking up my bio pellet reactor from the post office today actually.

[waynemah]

Not sure what the concern is on water changes. Where does this common 20% come from? Not sure how too much clean water is going to hurt your fish, given that the important parameters match.

I threw 20% out there because It's what I've had experience with. Personally if it came down to it and fish were dying, I'd do as large of a water change as fast as possible. But I don't want to be responsible for crashing someones tank with inexperienced recommendations. :mrgreen:

[Aquattro]

But I don't want to be responsible for crashing someones tank with inexperienced recommendations. :mrgreen:

fair enough :)

Think of it like this..if you bought a fish or coral, and the water was pretty close to your tank, would you acclimate or just add to the tank? Personally, if I get a fish from a friend's tank and we're anywhere near close to temp (that's all I'd look at), I dump the fish in my tank. That effectively is a 100% water change for that fish. I've never lost one to new water. Same with corals. I float a bit to equalize temp, then in it goes. Completely different water than it came from = 100% water change.
The bacteria you want to filter your tank resides on the substrate. The amount free floating will have no impact, so that's not an issue.

I suppose one caveat might be that if your tank is so filthy and the fish have become accustomed to living in sewage, too much of a good thing might kill it. I doubt this is the case :)

[Proteus]

I do 50% WC all the time. Though not cost effective I enjoy doing it for fun. Ans as for coral above water I wouldn't worry. Most of mine are exposed and if I'm making frags they sit on table for 5 minutes

[marie]

I have done as close to 100% water change as you can get (if you don't count the water still trapped in the rocks) with no issues.
If my nitrates were that high I would change out as much water as I could

[sirruckus]

for those of you who have done such large water changes - what method do you use to pull the water out of the aquarium? and replace it?

a pump seems to be the best idea for something that you would probably want to get done fast rather than relying on siphons

Thanks for all the input

[Aquattro]

for those of you who have done such large water changes - what method do you use to pull the water out of the aquarium? and replace it?

a pump seems to be the best idea for something that you would probably want to get done fast rather than relying on siphons

Thanks for all the input

I've had to drain my tank twice to catch fish. I used a large 2.5" hose to drain it into 4 50g drums. I then used a MAG 12 to refill the tank. Takes about 15 minutes total.

[Reef Pilot]

I used to have very high nitrates (around 100 ppm). Did many frequent large water changes, and while they would bring the nitrates down a little temporarily, they would climb right back up in time for the next water change (2 weeks). I think my rocks and sand was super saturated with nitrate, and they would just leach out again.

Interestingly, the fish didn't seem to mind, and even my soft and some LPS corals were doing fine. But I did have a major algae problem, and had to clean the rocks and sand constantly.

Tried a few other things too, like a refugium full of chaeto, but that had no effect at all.

Finally used MB7 and got a bio-pellet reactor and that worked, although it took quite a few months. Now my tank has zero nitrates and near zero phosphates, and now have SPS growing well.

[ocean diver]

The high nitrates could be caused by the media in your canister filter, if you don't need the canister filter I would remove it or at least clean it out once a week.

Way back when I started I did remove 80% of the water and then filled it half way up then back down leaving about 20% then filling up again, but with in a week it was right back where it was.......so I would find the cause and try to reduce that source.