Complete newbie here, do I need to do water changes if my nitrates are zero?

[Just Renee]

There is so much conflicting info online regarding water changes.  I've been trying to hedge my bets by just doing weekly 25% water changes instead of 50% because it just seems so disruptive to change out so much water.  I'm always nervous I'm going to mess with the balance I'm trying to create every time I do a water change.  I also rarely ever show nitrates because I started out with plants in the tank from the get go (at least, I think that's why I don't have nitrates?).  Now I'm looking up info on why my plants look rough in my little 6 gallon tank and I think it's a nitrate problem.  I just tested the water again (using API 5 in 1 test strips) and still no nitrates.

So I have a couple of questions I hope someone can help me with. 

1.  Do I need to change out any % of water if my nitrates are 0 and I can't identify any other reason the water needs to be changed (fish look good, other parameters look good, etc).  Should I wait until my nitrates go up to change the water?  Why AM I changing water if my nitrates are 0 anyways, what am I trying to remove?

2.  Does dosing with Easy Green add to my nitrates or is that something that needs to build up organically from the life in the tank?  

Thanks.  I have been looking up a lot and trying to learn but I'm still just very confused on the water change thing.

Edit:  I have very hard water, like my little 5 in 1 strip always just maxes out immediately.  Does that affect the need for water changes, like will all that hard water just build up from topping off over and over instead of removing with a water change?

Edited May 26, 2021 by Just Renee

[FrozenFins]

To answer your questions...

1. The only time you need to change water is when you test for either Nitrites and Amonia. Often that means doing weekly waterchanges but it varies from tank to tank.
2. Yes, easy green will add to your Nitrates. Nitrogen is a nutrient that all plants need. It seems very unlikely that you have 0 nitrates if your dosing easy green. do you mean Nitrites? You should aim for 20ppm nitrates and 0ppm of nitrites and amonia. 

You can post pictures of your plants and others can determine if it is a nitrogen defency. Seems very likely it is if you have 0ppm of nitrates. You can always dose more easy green until you hit that 10-20ppm of nitrates.

Heres a plant defency chart. A nitrogen defency looks like the bottom left leaf.

Edited May 26, 2021 by James Black

[Schwack]

1. Is a bit of a loaded question. Lots of very successful aquarists keep tanks with low-to-no water changes. As you've seen, with enough plants and reasonable stock levels you'll almost never see appreciable levels of nitrates. All of my tanks are in this spot, but I still choose to water change every 2-3 weeks to freshen things up and introduce trace minerals into the tank from my tap water. Water change to add to the tank, rather than to remove something. Having hard water shouldn't have much of an impact here, my water maxes out every test everything chugs along happily.

2.Yep, it'll add nitrates to your tank, but if you're heavily planted they'll likely be gobbled up quickly. You could probably tinker with lighting intensity or duration if you're seeing what appear to be nutrient deficiencies, but without a picture I think folks will have a hard time giving much in-depth advice.

[Just Renee]

Hi James, 

Thanks!  Yes, I mean Nitrates with an A.  My tanks are cycled, I am always showing 0 ammonia and 0 nitrites now.  I have what I think is a large number of plants in both tanks, some slow growing and some fast growing.  I assumed the fast growing plants were using up all the nitrates which is why it is usually showing 0?  

Please excuse the dirty glass, ugh, clean the glass before taking a picture, Renee!

[Just Renee]

So I have just dismal looking leaves that are anemic looking and pale.  The water sprite that is directly under the light appears scorched but I don't think my light is that strong so I don't know what the heck is the deal there.  I have a sword in the back that slowly looks to be coming back now that I gave it a root tab a couple of weeks ago.  The baby's tears is doing the best and growing a lot but it just looks very pale compared to pictures I've seen online.  Everything just looks... sad.

[lefty o]

sounds like you have a nutrient deficiency.

[Just Renee]

Here are some more pictures.  First, my phone is being FAR too generous with the color green... they look much more anemic and pale in real life.  

First is the baby's tears, they grow and grow but look funky and pale.  Then the scarlet temple that came from one of those gel culture packages from Petsmart and I don't know if they have ever really grown any new leaves... they just exist and look... sad.  And then my amazon sword that super struggled until I gave it a root tab and now it appears to be bouncing back.  You can see more scarlet temple next to it that looks super sad.

[FrozenFins]

I cant necessarily pin point the nitrogen defency. All though the waterspirte may not be liking a lot of light. Is there away that can you dim the light?

For one I would start dosing more easy green until you find that balance of 10-20ppm of nitrates. And see if that helps. 

[Just Renee]

Thanks, James!  Unfortunately, there isn't a way to dim the light on the Fluval Edge which is extremely annoying.  I had to buy a separate timer because it didn't even have one of those.  I do like that I was able to take those pictures from above the plants though, having the glass on top is pretty handy, when it's not a total nuisance.

[Isaac M]

Ok maybe I should not be answering a question this loaded this late at night (at least for me) but here I go 😂 

1. Water changes serve a lot of purposes. Often, nitrates build up in aquariums that have a lot of fish or people are feeding heavily and do not have much plants. If you have a lot of plants and few fish, nitrates or ammonia aka nitrogen will be limited as the plants will be utilizing it. It is often recommended that aquariums with nitrates over 40ppm or 50ppm get a water change. If your nitrates never reach that level due to the plants, there is no need to do a water change because of nitrates. 

However, there are other trace elements and things like kh that still matter. The nitrogen cycle will also slowly acidify water. These things are known as “old tank syndrome”. Instead of trying to explain this in a post, I think Cory explains it better in this video. Basically, water changes still need to be done for reasons other than just nitrates only. 

2. Yes you can let nitrogen build up organically in your aquarium but Easy Green is an all-in-one fertilizer which means it contains more than just nitrogen. Getting 20 ppm of nitrates from your fish is different than getting 20 ppm of nitrates from Easy Green as Easy Green will also provide the other 2 macronutrients (potassium and phosphate) and micronutrients so your plants will not develop deficiencies as shown in the graphic @James Black posted. 

Water sprite is a fast growing plant and thus requires a lot of nutrients. Given your nitrates are zero, I would recommend increasing your easy green dosage slowly (either add more on the day you dose or add more on another day) and observe what changes it makes in your plants. I would wait 2-4 weeks to really see the difference. 

I also would not be too worried about your aquarium light being too strong. Water sprite can be grown floating and it typically does not burn even though it is closer to the light. 

I hope that helps! Sorry for writing a whole essay in my attempt to help 😂

[Just Renee]

I'm glad I checked back in before heading to bed!  Thanks Isaac, that is a great explanation and makes a lot of sense.  The ph thing is worrisome as I already have slightly acidic water and am using crushed coral in my filter to add to the kh (which wants to be 0) and bring up the ph a bit.  It appears to be hovering at 7 now with the crushed coral.

Anywho, thanks, I feel like this all makes a lot more sense than all the mixed info I was finding online.

Edited May 26, 2021 by Just Renee
shoulda waited til morning to post, names are hard

[Isaac M]

@Just Renee I am glad that helped. There is so much information available now that “paralysis by analysis” is a very real thing now.  

It would be helpful however if you could provide your water parameters so we can look at your ph, gh and kh (do not worry, do this tomorrow, get some sleep haha).  

For a beginner or “newbie” as you said it, your aquarium looks really good. You are way ahead of where I was when I started. So great job! I personally think you are doing amazing! 

[Just Renee]

Thanks Isaac, that means a lot!  I definitely got interested in aquariums 50% for the plants and 50% for the fish, so a heavily planted tank was my goal from the get go.  Parameters for the small tank is:

Fluval Edge 6 gallons

NH3 - 0

NO2 - 0

now NO3 is 20 after dosing with easy green, yay!

pH - 6.5 - 7

Kh - fluctuates between 0 and 40

Gh - off the charts, immediately goes to 180 on my test strip and never anything less.

temp is 78.  I have fluval stratum and some root tabs under the stem plants.  Tony the a-hole betta, a single cory (trili-something), 4 yellow cherry shrimp and 2 nerite snails.  When I set this tank back up, I had to get a new light, so I got the one made for a Fluval Edge 12 gallon because it was supposed to be better for the plants, the original one for the 6 gallon was supposedly too weak.  I bumped  up the light from 8 hours to 9 to try to make the plants happier... I did that about a week or so ago.  The only other thing I can think of is that I set up a little baffle made from a soda bottle to reduce the flow from the filter.

[Isaac M]

It looks like you are on the right track. I would just keep an eye on the kh and make sure to keep the crushed coral in the aquarium. Keep up the easy green dosing and lets see where that takes the tank and plants. 

As far as the fish, I would try to get the cory some friends and have at least 3 of them. They are social little creatures. 

[Just Renee]

Yeah, I unfortunately learned about the cory needing a school after I bought her (him? whatever) but this tank is too small to add more, I think.  Especially because this type gets like 2.5 inches... eek too big for more than 1 I think.  I have a 20 gallon I'm starting to stock, I may move her there with some buddies.

[Isaac M]

No worries, we have all done that. I think moving the cory to the 20 with some buddies is perfect! 

[Patrick_G]

I don’t have much to add to the already good advice. I will say that I agree with @Isaac Mon the Sprite. Mine grow best close to a bright light. If they get leggy like the one in your pic I just cut off the stem and plant the top or let it float until you see some roots then plant it. 

[Daniel C]

I have hard well water so I use distilled water to top off for evaporation. I don't want the minerals and such in the water to keep becoming more and more concentrated. 

[Isaac M]

@Patrick_G that is great advice on the water sprite. You can easily propagate water sprite that way. 

@Daniel C yes that is a great way to not get too much of a single mineral. I would still test the water however just to make sure ph/ kh is not dropping too much.

[Just Renee]

Another question, because you guys are amazing!  Why does my kh keep trying to drop to zero?  I haven't removed the bag of crushed coral in my filter, it's still there.  What causes kh to decrease?  I don't know why my water is so hard with a kh so low...  my water also comes out of the tap fairly acidic, 6.5 using the API 5 in 1 strip.  Since adding the crushed coral, I'm up to 7, barely.

Edited May 26, 2021 by Just Renee

[Isaac M]

kh and ph have a direct correlation with each other. A high ph typically has a high kh. A low ph usually has a low kh.

Whenever the nitrogen cycle occurs, ammonia goes to nitrite and then to nitrate, free hydrogen ions are released into the water.

These ions will acidify the water by lowering your ph(ph is a measurement of the amount of hydrogen and hydroxyl ions in the water, more hydrogen ions means lower ph).

Kh, or “buffer” is a measurement of carbonates and bicarbonates in the water that pair up with the hydrogen ions and thus removing it from the water to keep it from lowering your ph. 

So your kh keeps dropping because it continues to buffer your water as your aquarium completes the nitrogen cycle throughout the day. The crushed coral slowly adds more back to the water to keep this process going. 

I am no chemist however, this is just my understanding of it as it pertains to our aquariums. 

[Just Renee]

Isaac, where were you during all my chemistry classes?  That was a great explanation and makes perfect sense.  Thank you!

[Isaac M]

@Just Renee haha no problem, I am happy it helped!