How much "bad stuff" do you actually remove during water changes...

[strawberryblonde]

Welp, I'm currently experiencing a mini-cycle with my juvie tank. I switched out the filter for a larger one and must have squeezed it too much when I rinsed it. Either that or it wasn't as completely seeded as I thought it was. LOL

Anyways, I noticed the juvies were a little off their feed yesterday afternoon (about 6 hours after morning WC). They perked up for a bit after the evening WC, but were back to not eating, and "twitching" this morning, like something was irritating them.

First thing I did was follow the recommended course of action I learned here on Simply. Grabbed my test kits and got to work. LOL

Ammonia was fine, but Nitrites were sitting at about 1.0ppm. Hard to tell for sure, but it was darker than blue and not quite purple. So between .75 and 1.0ppm. Nitrates were fine at 5ppm. Clearly a mini cycle and not an illness.

Did a 100% WC right after the tests. Tested again at 1pm and nitrites were rising again. They were just under .25ppm. Fish still not eating and still twitching. Added a small amount of salt and a double dose of Prime to neutralize the nitrites.

So then I got thinking, this is the perfect time to test out and find answers to one of those questions that nags at me. "how much of a harmful substance (bacteria, nitrates, nitrites and meds) do we actually remove when we do a water change?" Also "Is there a big difference between a 50% WC, a 75% and a 90% WC?"

And here's now I'm testing it in order to find answers.

Tested Nitrites at 6pm - were between .75 and 1.0ppm

1) I filled two large plastic tubs with water, added prime and let them sit for 20 minutes.

2) After 20 minutes I began a WC. I removed 50% of the water, then refilled with water from the buckets.

3) Tested Nitrites at that point and they registered .25ppm, so clearly a 50% WC wasn't enough to do much good.

4) Drained the tank a second time to 50% - since as best I can figure, that would be about equal to a total 75% WC if I included the initial 50% WC.

5) Filled the tank with the last of the "quickly aged" water.

6) Tested nitrites. They still weren't at zero! It was dark blue, but not pale purple, so something less than .25ppm. Still not acceptable for my fish to sit in overnight.

7) Drained again and this time did a 90% WC. In effect, I had removed more than 100% of the original water, but I also know that a wee bit remained since you can't ever get 100% out by doing it this way. Refilled with fresh tap water and Prime.

8) Tested nitrites and they read a nice pale blue - 0 nitrites...whew!

I'm going to retest at 9pm to see where I stand. At that point I'll add another dose of Prime and a wee bit of salt to tide them over tonight.

Tomorrow I plan to continue my little test starting with my morning WC.

What I've learned: A 50% WC is better than nothing, a 75% is much better and a 90% is the best bet. More results tomorrow as I switch it up even more.

[ronald sherman]

that's interesting as I was battling the exact situation the last 12 day's as I started a second discus tank and 9 juvie in a 29 gallon tank was delieved too my door by a member of this forum, Roland Teves very healty beautiful fish in and thought by taking a seeded yr old sponge filter asi had 4 in the 90 with 2 canister and used a new brand of benterial flural my tank would be pretty much cycle fish must be very healthy as ammonia read with 24 hr's between 1 and 2 continued added the fural with large 75% water changes and ammonia kept re-climbing again for 4-5 day's then went threw the same for nitrated for day 5-10 but amazing enough the fish eat flawless acted 100% normal in fact I have at least 12 different types of food's and I admire the job and have too recommend POLAND TEVES job he did as they imitated Kenny discus too the tee, I assume too my good water changes and taking care I haven't lost any now for the last 2-3 tank has been completely cycled and amazingly have noticed a vast improvement in them coloring a bit if the juvies did start too show stress in anyway I was prepared too add a second sponge filter from the 75 gallon, as it still had 3 left with 2 canister's also the 29 gallon does have a emp 280, with bio wheel, and a bag of bio-max I curious too how long i'm going too be able too use the 29 gallon as the grow out tank before having too move them too larger and will start a new threat 4 replies,

[LizStreithorst]

I know that I should test the tank water if the fish look off, but I don't. My first best guess is that the water isn't right so I change a ton. I like 80% for a huge WC, but I've done flopping on the bottom WCs more than once. It works. There is no such thing as too much clean water as long as the water is stable. I can't go straight from the tap. I have to age mine. Too great a pH swing if I don't.

[mastermamo]

Quick question. Why did u add salt? That doesn't make any sense to me

[nc0gnet0]

Salt will effectively neutralize the nitrites, about the only thing it is good for IMO.

[strawberryblonde]

Salt will effectively neutralize the nitrites, about the only thing it is good for IMO.

+1

It takes just a small amount of salt to neutralize nitrites. It's the only time I use it, unless I'm putting it on my fish and chips.

[mastermamo]

+1

It takes just a small amount of salt to neutralize nitrites. It's the only time I use it, unless I'm putting it on my fish and chips.

Hmmm ok

[mastermamo]

Salt will effectively neutralize the nitrites, about the only thing it is good for IMO.

But salt is also good as a chemical agent for skin irritations and a good disinfectant

[strawberryblonde]

But salt is also good as a chemical agent for skin irritations and a good disinfectant

If your discus has a skin irritation, as in flashing, scratching or twitching its fins, it's better to look at what is causing it, and then to correct the actual problem, than to add salt in the hopes that it will calm down the irritation.

Personally I wouldn't use it as a disinfectant in a fish tank! I'm not even sure I can think of an instance where you might use it this way. Can you give me an example?

Salt can be used for some external parasites, such as Ich, along with heat. It can also be used as a short term dip to remove excess slime coat. Those are both specific, extreme situations and it needs to be used correctly in both cases.

If you're up for some light reading, you might want to do some research, on credible websites...university sites, well respected fish expert sites, etc. to see what salt actually does when you add it to a freshwater tank. You might be surprised!

There is a delicate balance between a fresh water fish (especially discus) and the water they live in. Their bodies and internal organs are designed to operate at peak efficiency in plain water...without salt. When you add salt, you put extra stress on their kidneys as they try to regulate the change in specific gravity in the water. Do that often enough or for long periods of time and eventually the immune system will suffer as well as the kidneys.

[lipadj46]

But salt is also good as a chemical agent for skin irritations and a good disinfectant

The are much better and more effective options than salt for those things.

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[sandy]

Salt will effectively neutralize the nitrites, about the only thing it is good for IMO.

Hmmm I didn't know that


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[Gorf]

I would use Prime or Stability to control the Nitrites. This way the Nitrites are still available to the nitrifying bacteria.

[strawberryblonde]

I do use Prime Gorf, but thanks for making note of it for anyone else who reads the thread. Guess I wasn't clear enough on that, huh? =)

Though Prime converts nitrite to a less toxic form and allows nitrifying bacteria to continue to populate my filters, water changes are still the number one method of insuring that my discus remain healthy. Takes a couple of days longer to get through the cycle, but is much safer for them.

Ok, here's the morning report.

Tested nitrites at 8am and found them hovering between .25ppm and .50ppm. Did an 80% WC, then retested and nitrites are back to zero. Discus are lively and feeding well, but I'm still on reduced feedings till nitrites are holding steady at zero.

I'm curious to see how long nitrites remain at zero since the water change obviously didn't remove all of them, just reduced them to a level that the test can't register clearly. I'll be testing again at 10am and if still zero, again at noon.

I'm hoping by doing all this testing I can determine whether I can "get away" with smaller water changes, just how long it takes for the "bad stuff" to build back to a dangerous level and how many water changes a day I have to do to keep levels safe if I don't do large water changes.

[strawberryblonde]

Ok, after two days of water changes and testing nitrites here are the results:

1) An 80% water change will reduce .50ppm nitrites to zero. Nitrites rise to .50ppm in about 10 hours.

2) A 60% water change will reduce .50ppm nitrites to less than .25ppm, but not quite zero. Nitrites rise to .50ppm within 4 hours.

3) A 100% water change will reduce .50ppm to zero. Nitrites rise to .50ppm after 16 hours.

4) A 100% water change twice a day keeps nitrites to .25ppm at their highest point (just prior to the second water change)

Soooo, even though the action of nitrite growth is different than bacterial, mold or fungal growth, the basic principle remains the same. ALL tanks contain some amount of harmful bacteria, mold or mold spores and fungi. Though they may propagate at a slower pace than nitrites, larger water changes will remove most of them and reduce the populations which slows the growth.

[pcsb23]

Mini cycles or incomplete cycles can be a royal pain in the backside ... hope you sort yours soon enough.

Just a quick word re salt and it's role in "controlling nitrites". Basically it doesn't do anything to the nitrites them selves, these remain available to the filter to be converted to nitrates. What happens is that the chloride ion latches onto the fishes hemoglobin where the nitrite ion would have, in effect replacing the nitrite in the blood with chloride. Nitrite stops the hemoglobin from transporting O2 around the fishes body, so the nett effect of using salt is that the hemoglobin maintains it's ability to transport O2 around the fishes body.

Using salt was the right call here. It does have other valuable uses in the aquarium too, but that is not for this thread.