Should I do water changes

Should I do water changes if my Nitrates aren’t high? I have a 125 gallon with 16 Peacock cichlids in it. It’s been over 4 weeks since I’ve changed the water 50% change.

 

It may not be necessary, but it can't hurt.

 

Yeah, it can't hurt.

 

Should I do water changes if my Nitrates aren’t high? I have a 125 gallon with 16 Peacock cichlids in it. It’s been over 4 weeks since I’ve changed the water 50% change.

Don't go just by Nitrates and also not by TDS. There are many wasteproducts:
Nitrogen compounds (Nitrates etc.), carbon compounds (DOC), organic acids, hormones, enzymes... a whole array of stuff we mostly can't test for. Especially due to hormone buildup in a Malawi tank do a weekly waterchange, nonetheless.

 

It's also fresh minerals et al you are adding with fresh water.

 

yeah, old tank syndrome isn't just nitrates.

the nitrogen cycle creates acids. if you go too long your pH and KH will drop.

 

there's also a phosphorus build up from feedings and poopings to account for, this will eventually send the GH through the roof, especially in a usually non-planted African Cichlid tank.
Keep in mind it takes roughly 30 days for waste to break down completely, that waste will eventually release all of the unused components of the foods given, and after 30 days start messing with the parameters and get worse the longer you don't do a water change/ clean out waste, so even if it's not necessary by nitrates, it's still kind of necessary for the reason above.

I'd also assume you are buffering your water to keep the pH higher, Phosphorus build up will create phosphoric acid, and that will eat up your buffer and then drop your pH, same as carbonic acid or nitric acid would from carbon or nitrogen.

So, regular water changes are pretty important, it might be fine now, but long term it will be a headache down the road to straighten back out when these things not tested for stack up as acids in the water and deplete the buffer then drop the pH.

I'd say if you can keep nitrates low by doing a 1x a month water change, and it stays like that, that's awesome and awesome for the fish. However a lot of times 6 months down the line and no substrate cleaning or spots that are difficult to get to under big rocks, that's where it starts rising and getting dumb on ya, it also happens as the fish grow in size and eat more ect. so in general it's a good habit to have as routine. the longer term break down of waste and uneaten foods in the substrate is usually hiding a secret that appears with enough time when you finally decide to mess with it, and then it's a mission to get it back in order again.

 

In theroy you could test GH and KH phosphate and maybe more things like advanced reef keepers do. But it is way easier to just change some water every few weeks.

 

there's also a phosphorus build up from feedings and poopings to account for, this will eventually send the GH through the roof, especially in a usually non-planted African Cichlid tank.

How would phosphorus build up raise GH? GH doesn't even measure that stuff. Phosphates go high in Malawi tanks. And GH is usually high in these tanks anyway. We kept our Malawis at 20°GH.

 

Replacing water also replaces micro nutrients in the water. I've noticed that even when nitrates remain low, things just start to go wrong if I go too long without a water change- plants get deficiencies, snail shells degrade... Admittedly, you may not have either issue in a malawi tank, but I would still be cautious.

 

Admittedly, you may not have either issue in a malawi tank

You are right for a lot of set-ups, and you are also right with assuming that this is no issue in a Malawi tank.

 

The answer is always yes you should do a water change.

 

A weekly 50% WC on a big 125 gal. tank can be a bit overwhelming & in most cases unnecessary.
A weekly 25% - 35% WC should be fine.
Make a 50% WC if you notice water clarity or declining parameter issues. A big WC just before adding new fish is a good idea.
It's also wise to make a 50% WC at the first indication that a disease might be present.

 

How would phosphorus build up raise GH? GH doesn't even measure that stuff. Phosphates go high in Malawi tanks. And GH is usually high in these tanks anyway. We kept our Malawis at 20°GH.

Yes It does. GH tests mineral Ions in the water. I know a lot in the hobby says specifically "calcium and magnesium" and that's what most people are concerned with also because in freshwater they are similar in depletion (not so in saltwater but that's a different story) , but nonetheless it's a General Hardness Test and is testing for salts (dissolved minerals) people are only concerned with calcium and magnesium these are the most abundant cations detected in the test, there are plenty of minor cations also detected in a GH test, but everyone is assuming lakes or rivers are stable mostly, and pools are getting tests and amendments to keep the water safe for swimmers,,,,, and aquariums are getting regular water changes... being tended to and not allowing for depeltions or buildups.

If you have a Malawi tank or whatever and you are using rift lake salts the GH is high and it is salts (minerals) it doesn't mean it isn't recording phosphates in the test or iron, zinc, or potassium or other minerals which make up the test result, just that nobody cares about the rest besides calcium and magnesium which are the majority and because it's small amounts of the rest, which aren't a problem when doing regular water changes.

Doesn't mean down the road after 6 months to a year or more of top offs for evaporation or never cleaning the substrate and having this stuff build up and trickle out and doesn't come out with water changes that those numbers don't become significant, and a problem.

 

Yes It does. GH tests mineral Ions in the water. I know a lot in the hobby says specifically "calcium and magnesium"

Now our respective definitions are diverging. To my knowledge "Gesamthärte" measures the kations of alkaline earth metals and their compounds. That includes the other AEMs like barium and in practice includes the carbonates, sulfates, phosphates and other compounds with these metals but not all kations regardless of composition. Hence the total sum of phosphates has to be measured with a separate test.

 

if you have enough extra time on your hands just do it

 

The answer is always yes you should do a water change.

I agree. That reminds me of a YouTuber I followed for a while. He said something like "Don't test your water to see if you need to do a water change. By the time you do that you could be half finished with the water change. Just do the water change and skip the testing."

 

yeah, old tank syndrome isn't just nitrates.

the nitrogen cycle creates acids. if you go too long your pH and KH will drop.

What is KH

A weekly 50% WC on a big 125 gal. tank can be a bit overwhelming & in most cases unnecessary.
A weekly 25% - 35% WC should be fine.
Make a 50% WC if you notice water clarity or declining parameter issues. A big WC just before adding new fish is a good idea.
It's also wise to make a 50% WC at the first indication that a disease might be present.

So I did a water change. 50%. Added Seachem Prime and still I found my fish all looking bad and at the bottom of the take looking SH$ty. The PH dropped from 8 to 6.3. Could this be the problem? I added PH up from API trying not to shock them too much with the level change. Brought it up to 7.2 before heading to bed. I then added API aquarium salt and Seachem Sablility as per directions on the bottle. Is this the correct way to do water changes with a well with low PH levels?

 

KH is the measure of carbonates which directly affects pH.

yes, a sudden change in pH will adversely affect your fish. i know a lot of fish keepers use baking soda for acidic water. Also, crushed coral and limestone.

 

Am I the only one that just wants to see pictures of the fish?

 

Should I do water changes if my Nitrates aren’t high? I have a 125 gallon with 16 Peacock cichlids in it. It’s been over 4 weeks since I’ve changed the water 50% change.

yes you should, monitor your nitrates. Not sure if this is still true, but seachem prime will skew your nitrate readings so give it a couple of days if you use seachem to treat your water before you check again.t Check them after a week and if you are good then check again a week later. This should tell you how much you can get away with. Could be a filtration issue, not having enough or over feeding over stocked.

there's also a phosphorus build up from feedings and poopings to account for, this will eventually send the GH through the roof, especially in a usually non-planted African Cichlid tank.
Keep in mind it takes roughly 30 days for waste to break down completely, that waste will eventually release all of the unused components of the foods given, and after 30 days start messing with the parameters and get worse the longer you don't do a water change/ clean out waste, so even if it's not necessary by nitrates, it's still kind of necessary for the reason above.

I'd also assume you are buffering your water to keep the pH higher, Phosphorus build up will create phosphoric acid, and that will eat up your buffer and then drop your pH, same as carbonic acid or nitric acid would from carbon or nitrogen.

So, regular water changes are pretty important, it might be fine now, but long term it will be a headache down the road to straighten back out when these things not tested for stack up as acids in the water and deplete the buffer then drop the pH.

I'd say if you can keep nitrates low by doing a 1x a month water change, and it stays like that, that's awesome and awesome for the fish. However a lot of times 6 months down the line and no substrate cleaning or spots that are difficult to get to under big rocks, that's where it starts rising and getting dumb on ya, it also happens as the fish grow in size and eat more ect. so in general it's a good habit to have as routine. the longer term break down of waste and uneaten foods in the substrate is usually hiding a secret that appears with enough time when you finally decide to mess with it, and then it's a mission to get it back in order again.

Reminds me of a throw down tank i had, never did any real water changes just topped it off and the day I did I lost a bunch of fish. Frog in the pot, a lot of fish will acclimate to poor water parameters then when you change that suddenly, they can die. I suspect from pH shock, I've seen it happen not just to me. Always good to test your tap water pH and tank water pH, if its way off then do smaller water changes to protect the fish

 

Is this the correct way to do water changes with a well with low PH levels?

This is something you should have probably mentioned from the start. You would have gotten completely different answers. No offence, but this is literally vital info.

As you keep Malawi cichlids you should already know they need harder but especially alkaline water.
If your source water is rather soft and acidic crushed coral or adding chemicals is going to be exhausting, expensive and prone to accidents and mistakes.
If you want to get around all this the most practical solution are rocks of limestone as decoration. The water then will take up all necessary minerals and carbonates until saturated. Then, depending on the levels of your sourcewater, situations like this won't happen that easily.

It is always a good idea to know GH and KH of source water and tank. So I recommend testing for both. While the well won't show much change (if at all) you should now start to monitor the levels in the tank, so you can come up with a longterm plan.

 

I have a 200L community tank, platys breeding happily, plus a few guppys, 2 x dwarf gouramis and 3 sterbai corys, a few danios. Tank is fairly heavily planted

A while back I had issues with nitrate spikes, I was changing water (up to 40%) every few days to get it under control. Tiresome. I added some more plants, including some azola and duckweed, mainly to reduce light as I had a mild brown algae issue, which is now also no longer a problem, and provide shelter for fry.

Here's the thing... since August, all my water tests are PERFECT. pH fairly stable around 7 (I do now and then add a little pH Up), but ammonia, nitrite and nitrate all remain at ZERO... and I have not changed water once since then! Seems to good to be true.

Just tested KH - 4, and GH - 6. So they are not going way up either.

I've read the numerous posts that advocate changing water regardless of tests... but, to be honest, I'm liking the low maintenance, steady state I have achieved. I put it down to the plants removing the bad stuff, and am a little reluctant to disturb this very happy situation.

Any comments? Should I just keep doing the same thing... it seems to be working just fine!

Thanks,

 

I'll be honest with you on this, if you have nutrients entering the aquarium from decomposition or fertilization and topping off for evaporation, it can be a really long time before a water change is done.

However, the time will come where it's inevitable. you'll notice it in an increasing GH and a decreasing KH, by just topping off for evaporation unless using distilled or RODI water, minerals will slowly build up and GH will increase, while acids produced will wear away the KH.

You kind of have to keep an eye on what it's doing every so often and water change when necessary, it will take a lot of water change to bring down GH and bring up KH when it becomes painfully obvious there's a OTS problem brewing and take it back in line with your source water or the water parameters you want to keep for your fish. I myself am guilty of doing it, then getting complacent and simply not checking for a couple years until I tried to introduce new fish that died immediately from osmotic shock or something like that. by then GH was like 21dGH and KH was like 0 dKH.

Even if youi have the plants working out the nitrates, the natural cycle for water in general is evaporation, and precipitation (rain) for top offs. the mistake people and myself make is topping off with tap water for evaporation which keeps adding in minerals and nutrients.

Rain, distilled or RODI water is what you'd need to keep it going a really long time without it heading into OTS territory. The nitrate spike you experienced was a precursor to OTS, which you countered with water change and then adding more plants to use up the decomposition nitrates the tank is producing which would normally compound over time without plants.


it can work, maintaining the balance can be difficult, not growing complacent over time and leaving it on autopilot can be a problem for some people. You may find when you get about cutting back plants they won't be as effective and nitrates rise, or find a mineral or nutrient depletion happen if the plants get overgrown.

Always monitor, top off with non-tap water, something that isnt' mineralized. you'd be surprised at how much flouride builds up for instance, the main two used are sodium salts NaF, and Na2SiF6, only RODI can eliminate it from the tapwater if it's in there, and that will build up over time in small amounts by not doing water changes, a small amount of flouride is found in all water naturally, but in treatment many places add like 1mg/liter to prevent tooth decay.
Something like flouride will build up over time and increase the GH.

Anyways, I'm a big fan of don't fix it if it ain't broke. But also, a big fan of monitor and maintain now a days. It can work but it's a balance, and testing and re-balancing is going to be necessary to maintain it running right so it doesn't run up, or deplete on you.

 

Thanks for the detailed reply SparkyJones.

I should have added in my OP, the only water I have available is from a bore... which sounds scary, but it is actually a plus. Not far from where I live, they sell this stuff (from the same aquifer) as bottled spring water. It is super clean, soft, and obviously has no flouride treatment etc.

That said, I take your point about slow buildup of minerals as water evaporates. In my tank, TDS is 495... whereas my topup water is only 240... so yeah, there is already evidence that some minerals or salts are accumulating.

The only thing I do is adjust pH when I top up... as my bore water is somewhat acidic so I add pH Up to keep things around 7. Only other water quality issue I have is it is too soft for snails... ramshorns just don't survive, but I can live with that...

I'll keep monitoring, and one day, I'll do a change, just to be sure!

Thanks.