So whats wrong with large water changes?

[stanlalee]

I recently read a thread where one suggested large water changes mess up something (cant remember what). I do 50-60% water changes once every 3-4wks (probably closer to 60% if not more since its a 30 gallon and I vacuum out and fill up with three nearly full 5 gallon buckets worth of water per change and have 30lbs of liverock and CC which take up space).
So my results before and after water change (been about 3wks since last change which was the same method. Instant ocean salt, home installed Hydrotech treated RO water. Testing about 5hrs apart. Tank has three fish: damsel, FP clown and LM blenny (about 4" total) and four crustasceans: fire shrimp, sallylightfoot, small green emerald, small hermit crab. Filtration: 30lbs live rock, sea clone 100 protein skimmer and skilter 250 skimmer turned off, used only to circulate water thru activated caron cartridges (yeah I know the two allegedly most suckiest skimmers on the market. I'd buy better but my testing doesn't warrant spending any more money.
nitrate before: <10ppm >5ppm nitrate after: 0ppm (aquarium pharmacuticals)
phospate before: 2ppm phosphate after: 0.5ppm (aquarium pharmacuticals)
pH before: 8.0 pH after: 8.1 (tetra)
dKH before: 15 dKH after: 11 (tetra)
sp gravity 1.023 before and after
few things:
1)why the heck cant I get my phospate level to 0.0 thru water changes, its always between 0.5-2ppm. Is that range acceptable for hardy soft corals?
2) stirring up crush coral causing a nitrate spike is pure myth. I vacuumed the crap out of it (non stop until over half the water in my tank was gone). I never get a lot of dust or cloudyness to begin with because I do it routinely. In fact I've never had a real problem with crushed coral substrate and high nitrates period but thats another topic all together.
anyway back to the question, why should I stop doing large water changes and do smaller more frequent ones? I'd all but hate dragging buckets in my living room and disturbing my tank every week. I do supplement with Kent calcium, stromium and mang (u do the spelling) and iodine routinely so renewing elements shouldn't be a problem I wouldn't think.

 

[rygoodm6]

by doing large ones you are messing with the cycle...taking alot of the good stuff out and making it start over...small ones dont do that...just a little tip trash the cc

 

[stanlalee]

Originally Posted by rygoodm6
by doing large ones you are messing with the cycle...taking alot of the good stuff out and making it start over...small ones dont do that...just a little tip trash the cc
how is it messing with the cycle, all the natural bacterial filtration is attached to the rocks and substrate? Plus it should show up in testing if the cycle is disturbed no. Thats what I need to know, what specifally in the cycle or trace element (or any kind of) depletion does it cause that makes it any worse than weekly changes.

 

[jjlittle]

My thoughts and from what I have seen is smaller ones weekly seem to do better ,one for you would be keeping more of the good bacteria in and not giving to much time for the bad to generate nitrates / phosphates . I have CC to with no problems and I never vaccum it . The only time I recommend a large water change is when nitrates / phos are very high and you really need to get them down though if you feed correctly and proper filtration you should not get high readings . I think your keeping readings for you may be over feeding alittle and your going 3 weeks without water changes which would give it time to build up. I would suggest trying smaller water changes weekly and i am not sure of your feeding habits but I only feed every other day and all is well & stable.

 

[stanlalee]

thats what I'm confused about, is the bacteria IN the water significant enough to worry about depleteing? I rarely here any mention or discussion of it. I only hear about the significance of bacteria on solid surfaces.

 

[rygoodm6]

yes there is stuff in the water. if there wasnt we would all do large water changes. hell if there wasnt we would all do 100% changes and not have to worry about anything. larger water changes can send you through a little cycle. not saying you shouldnt do them, just wouldnt advise to do them.

 

[aw2]

There is bacteria in the water yes, but not enough to cause any harm by doing a large water change.
The majority of the bacteria, in the tank, is on the hard surfaces (rock, substrate, filtration equipment, etc).
I commonly do 50% water changes on my 200gal. tank with no ill-effects.

 

[danedodger]

This is a topic of a lot of debate! There are many on the side of less frequent, larger water changes then those on the side of more frequent, smaller water changes. I say whichever works for you and your tank inhabitants is the right way to go.
If our aim is to maintain stability of water parameters at the generally accepted "proper" levels without big, sudden changes in water chemistry, though, it seems to me that smaller, more often water changes would be the better choice.

 

[aw2]

Originally Posted by DaneDodger
If our aim is to maintain stability of water parameters at the generally accepted "proper" levels without big, sudden changes in water chemistry, though, it seems to me that smaller, more often water changes would be the better choice.

But, if you're able to have an extra container to keep saltwater/freshwater and are able to keep it at the same parameters of your tank, then it's not something you have to worry about.
I keep 4 35gal. Brute trashcans full at all times. 3 with saltwater, matched almost perfectly to my tank water and the other one for freshwater.

 

[ophiura]

I wouldn't be concerned about the bacteria at all...there is little in the water column...I would be be concerned about significant differences in pH, temperature, alk and salinity. While it may not harm fish, it can cause serious harm to invertebrates if a lot of care is not taken to ensure they are the same. This is why I discourage extremely large water changes.
In addition, doing extremely large water changes on tanks with water quality issues can be major problems and disruptions. More than few times, when I worked in an LFS, did people lose all their fish thinking they were helping them. In these cases, water quality is so far out of wack that the large water change actually caused more harm. Often in freshwater systems - they would have very very low pH, and very very high ammonia due to lack of long term care of the system. But the ammonia is not toxic at these very low pH. They do a big water change, bounce that pH back up, and bammo...kill everything with an ammonia spike.
I think it can be somewhat more stressful on tank inhabitants to do large water changes if it is not needed. A lot of care must be taken to ensure that you have everything back in balance. If you take those steps and mix water well in advance, it may not be such a concern. And even if you don't, it is maybe not so much of an issue for fish...but you could cause serious issues with inverts if you had such sudden fluctuations.

 

[danedodger]

That's what I was trying to say but Ophiura said it better

 

[murph]

If it works dont fix it.

 

[turningtim]

Murph agreed! But things change. I was doing 20% every 2 weeks but as I purchased new more "delicate" corals (nothing more than moderate care level) I noticed that some of the creatures were irritated and it took a couple days for things to rebound from the W/C. I felt I took the greastest of care with the new water so it matched what was in the tank. Now I do 10% every week and I do not see any stress on the inhabitants. So, I guess what works now may not work later.
ophiura, How much do you think that elements that aren't or can't be tested for are responsible for such irritation or stress. I mean salt has 70 elements in it and we take alot for granted, don't we?
Thanks,
Tim

 

[ophiura]

Originally Posted by TurningTim
ophiura, How much do you think that elements that aren't or can't be tested for are responsible for such irritation or stress. I mean salt has 70 elements in it and we take alot for granted, don't we?
Thanks,
Tim
I think this is an extremely good point and worth thinking about...add in the potential for variability between different batches of salt as well. As you noted, you were seeing stress in your animals. I still prefer smaller more frequent water changes when inverts are involved. People need to watch and see what happens!

 

[mudplayerx]

The stress caused to fish and inverts by large water changes makes them very susceptable to diseases and sudden, unexplained death. You have to realize, the oceans are HUGE, there is never a large change in any water parameter in the ocean. Most critters that we have in our tanks are wild-caught, meaning they are not used to large water changes, and will more than likely respond poorly.

 

[harndog]

I am on the other side of this. In my 75 i get about 1 gallon of evaporation a day. I just add fresh top off water. This is in a sense 7 gallon water changes every week. that being said I have not changed more than 5 gallons at one time and only did that twice in the last year. Don't get me wrong most people don't have this kind of luck but I am being honest here. I have had an LTA in the tank for over 6 months and he has grown almost twice his size even after on his second day he had a bad accident with a maxi jet 1200. My parameters always check out good. I think most of my success can be attributed to my DSB, skimmer, emperor 400 that I change filters every month on. and my wet dry. Also have 3 MJ1200 two with wave maker's. about 75lbs of Live rock. It seems this is a rarity or everyone else is just to scared to get flammed for admitting this but the proof is in the pudding or corals in the case lol. IMO no need for large water changes unless your tank is overstocked and your levels keep going haywire.

 

[diane4]

Replacing water from evaporation is not the same as a water change because water is escaping and the polution disolved in the water is not escaping.
I am a big proponant of water changes. I change my saltwater tanks (I have 3 and 2 are reef) every week, not more than 1 1/2 weeks apart and each time it's about 25%. Once every other month or so, I do a bigger one yet, around 60%.
As long as the water you have made up is the same temp, salinity and ph - and it is airated and well mixed, you can't go wrong.
I insist on big water changes. People talk about the stress water changes cause fish to endour, I think the time the water takes to change is far less stress than a dirty tank all the time can be stress. I personally think there is nothing more iimportant than good water quality and one must do whatever is necessary to achieve it. For me, I like doing water changes. Tank looks and acts healthier after the tanks settles from the water change. My tank inhabitant appreciate their water changes.
My 5 freshwater tanks, I drain their tanks every week to about 2 inches above their heads - they love their water changes. They change to vibrant colors and swim through the water on the return.
Think of it as taking a shower for a human. The tank animals live in an eclosed glass cage and the fresh water replenishes lost nutrients, oxygen etc. It tends to rebalance things.
Buckets - nah, use a python. And yes, I do drag out a 44 gallon rubbermade trash pale to the kitchen every week to make up the saltwater for changes, but it a labor of love.
I sometimes think that some folks that don't believe in regular water changes is because it costs money for the salt and it is a pain in the bippy. But it's so worth it.

 

[mikeyjer]

Originally Posted by diane4
Replacing water from evaporation is not the same as a water change because water is escaping and the polution disolved in the water is not escaping.
I am a big proponant of water changes. I change my saltwater tanks (I have 3 and 2 are reef) every week, not more than 1 1/2 weeks apart and each time it's about 25%. Once every other month or so, I do a bigger one yet, around 60%.
As long as the water you have made up is the same temp, salinity and ph - and it is airated and well mixed, you can't go wrong.
I insist on big water changes. People talk about the stress water changes cause fish to endour, I think the time the water takes to change is far less stress than a dirty tank all the time can be stress. I personally think there is nothing more iimportant than good water quality and one must do whatever is necessary to achieve it. For me, I like doing water changes. Tank looks and acts healthier after the tanks settles from the water change. My tank inhabitant appreciate their water changes.
My 5 freshwater tanks, I drain their tanks every week to about 2 inches above their heads - they love their water changes. They change to vibrant colors and swim through the water on the return.
Think of it as taking a shower for a human. The tank animals live in an eclosed glass cage and the fresh water replenishes lost nutrients, oxygen etc. It tends to rebalance things.
Buckets - nah, use a python. And yes, I do drag out a 44 gallon rubbermade trash pale to the kitchen every week to make up the saltwater for changes, but it a labor of love.
I sometimes think that some folks that don't believe in regular water changes is because it costs money for the salt and it is a pain in the bippy. But it's so worth it.
I don't completely agree with you on draining out so much water, but if it works for you go ahead. I have tried the same method on my freshwater tank before but I kept on losing my angel fish until I cut down the water changes, I am keeping them ALIVE! In my very first tank, I did drain out the water and replacing it with freshwater in large volumes and managed to keep two angels alive for years. But as time goes on, I got older and more tanks I find by doing large amount of water changes, your keeping too clean of a enviroment for them so if there's any changes, they'll suffer from it cause they're not able to keep up with the bacteria that's within the tank. I have read that most angel fish breeders keep their tank in a very clean enviroment by doing large amount of water changes and that's the reason why most people can't keep them alive when they bring it to their enviroment. They're more susceptible to diseases since they've been living in a absolute clean enviroment!!! I know saltwater tank isn't the same as freshwater tank, but I think the same method applies. IF there's any specific changes within the water, it can stress out your fish, corals, and especially inverts who will be affected by it first. I lost my first snail when I dump RO water into my tank, he was near by where I was putting in RO water, from such a dramatic change in PH, etc etc. He fell off and died later. I've been more careful since then, when I replace the evaporated water with RO water, I pour it where there's no inverts or anything near by. Like what was mentioned above about disrupting the system with large water change, it's pretty much the same as a freshwater. The most I ever do is 25% when something goes wrong. I believe you can test your water quality as much as you want to match your existing tank, but what if that 1% of something doesn't show up in your test. It's easier for your existing tank water to dilute with the fresh batch water then to have nothing to dilute down with to ease out any potential problem. I hope all this makes sense. :happyfish

 

[diane4]

One of my freshwater tanks is a 58 gallon tank that has 9 black hi fin skirt tetras and 6 blushing koi angels. I do the same big water change on them and have them about 6 months and they have doubled in size. They do well and I give them the big water changes.

 

[promisetbg]

Originally Posted by Stanlalee
, is the bacteria IN the water significant enough to worry about depleteing? I rarely here any mention or discussion of it. I only hear about the significance of bacteria on solid surfaces.
The bacteria in the water is minimal...as you suspect it is mostly on the surfaces in the tank...rock,equipment,etc.
I think you are wasting your money a bit...a 50 % WC is good about once every six months or so...other than that 25 % would be sufficient.I tried the smaller more frequent water changes...I did'nt like the results I was seeing.I have gone back to 20-25 % every two weeks.On my nano I change a couple gal. a week since it has no skimmer or refugium.