Seachem Purigen Head Scratcher

[Musicmanryann]

Hey all, I am posting this here, though I am not sure if it is a filtration issue, water parameters issue, and/or where the two overlap, but I had an experience last night that was a real head scratcher. I am sort of a newb so that isn't saying much I guess, but I have done a bit of searching within here and googling about what happened first and can't seem to find anything, so hoping the many seasoned veterans may be able to provide some insight. I originally posted about this within my journal, but also posting here as I am worried about it happening again, and still struggling with lower pH a bit. Below is what I posted, but if you don't want to go to the journal, the context is that yesterday I added Amano, zebra shrimp, and nerite snails, to my first planted tank yesterday and this is what transpired:

" Every once in awhile I always tilt the biomaster from side to side to release trapped air inside. No idea why I do this, I think it might help the flow or something if air isn't trapped or whatever, but yesterday I did it and a big cloud of white murky water came gushing out the lily pipe and clouded up the tank, along with these very tiny squiggly wormy things. Not wider than a hair and not much longer, but definitely squiggling on their own accord. I must've knocked something loose, I guess. I had to run for a bit and when I got home the tank was back to normal, thankfully. However, the episode did remind me I keep forgetting to add Purigen to the filter to get a good polish. During the dark start I obviously didn't care about this, so I decided i would wait to add the Purigen until I get the tank planted and I keep forgetting. Well tonight, for some reason i remembered and for some reason I was bound to make it happen. Once the lights turned off, I pulled open the biomaster and added in a bag of Purigen. Easy enough, I popped the lid back on and turned it all back on and got things flowing again, but once again Tilting the canister back and forth. While I was doing this I noticed out of the corner of my eye the Amanos started going nuts. Something was wrong. After some initial troubleshooting I pulled out my pH meter and even though an hour ago it was reading 5.85, it was now reading 4.45. What the actual #*&$😟. The first thing my mind went to was the Purigen. I quickly grabbed it back out the filter and got the filter running again. Then I decided to do a quick water change. This made the pH go up to 4.65. Not good enough. The amanos were still acting frantic, and the zebra snails had retreated to above the water line. Not good. After frantically trying to figure out what to do, (there wasn't time to come here and ask advice) I ended up just running fresh RO water (it is same temp as tank) into the tank while simultaneously draining the water, while simultaneously watching the pH meter go up. About five minutes later the pH was above 5.25 and I started getting worried about re-mineralizing the water, so I stopped and got the GH where it needed to be. By this time the shrimps had seem to calm down and the snails were retreating back into the water and back to cleaning the aquarium walls. I decided it was time to leave well enough alone. I am leaving the lights off for now, hoping everyone will calm down in there overnight. Without the light I cannot see if the Tangerine Tigers are ok or not. The Amanos seem fine. Time will tell I guess....?

What happened?? I have looked it up and seachem says Purigen doesn't alter water parameters. I currently have the bag of Purigen sitting in a bowl of water that has a pH of 4.35. That same bowl of water was at 5.85 before I added the bad of Purigen. I feel like this has something to do with my low kH (using Amazonia so KH is <1), but I really am at a loss Another thought I had was when i opened the filter there were pockets of anaerobic activity in there and introducing a bunch of air disrupted that releasing Hydrogen sulfide (I did smell sulfur during my troubleshooting) . Here though, I am admittedly grasping at straws, and talking about things I don't know nearly enough about. Current parameters are Zero NH3, NO2, > 10 NO3. pH 5.25. (GH 7, KH <1) I have an aerator stone going hoping to add in as much O2 and remove as much CO2 as possible, but no idea if that is stupid or pointless or both. All I know is whatever happened it caused a very fast and drastic change to my pH. Any thoughts about what may have happened, and or what I may do to prevent it in the future would be more than welcome. It was a bit of a stressful saga. Lol.

Like I said, this might be an issue with my water parameters, but even today that bowl of water with Purigen is reading 4.15 on pH meter. I mean, the pH drop i feel was almost instant after I turned the filter back on after adding the Purigen. I mean, I know several on here don't think that highly of purigen, but I'd still like to use it, but also don't want to kill my cute little shrimps and snails with highly acidic water either. Fortunately it appears most survived the episode (the T Zebras are hiding a lot today) Even today, the water is a little more acidic that it was before when it was pretty stable. If anything I'd like to learn about what happened as i am curious. Thoughts?

Thanks in advance!

Ryan

 

[_Maq_]

When sulfides (par example hydrogen sulfide) are oxidized they turn into sulfates. Simply put, into sulfuric acid.
It seems that your canister filter is poorly oxygenated and some sulfides are trapped within. When you shake it, these sulfides are released and get quickly oxidized -> pH drop.
You'll have to completely clean and rearrange your filter, I'm afraid. Sulfides are poisonous.

 

[MichaelJ]

I mean, the pH drop i feel was almost instant after I turned the filter back on after adding the Purigen.

Yep! Thats a head scratcher! ... Could it be those Canadian wildfires that is blocking the sun here in the upper midwest? LOL Well, seriously. I have never heard of, or experienced that Purigen would alter the pH. I wonder if you got a bag from a batch that was somehow "polluted" ...

I know several on here don't think that highly of purigen, but I'd still like to use it,

I am a frequent Purigen user and have been a user for years now. It's great for clearing up tannins and also offer some water polishing properties. I used to use it all the time, but after getting into botanicals and learning that it may degrade some of the medicinal properties of the botanicals I only use it when my waters starts to look like thin tea - it also tends to lower the flow in my filters considerably!.

Cheers,
Michael

 

[MichaelJ]

When sulfides (par example hydrogen sulfide) are oxidized they turn into sulfates. Simply put, into sulfuric acid.
It seems that your canister filter is poorly oxygenated and some sulfides are trapped within. When you shake it, these sulfides are released and get quickly oxidized -> pH drop.
You'll have to completely clean and rearrange your filter, I'm afraid. Sulfides are poisonous.

Could be! Yes, and the Purigen will only make matters worse by restricting flow.

Cheers,
Michael

 

[MichaelJ]

Hi @Musicmanryann I just visited your journal ... if I am not mistaken your tank is barely 14 days old!?

@_Maq_, to me it sounds somewhat unlikely to me that sulfides would build up that fast? I mean the flow through the filter would have to be almost absent.

Cheers,
Michael

 

[Musicmanryann]

When sulfides (par example hydrogen sulfide) are oxidized they turn into sulfates. Simply put, into sulfuric acid.
It seems that your canister filter is poorly oxygenated and some sulfides are trapped within. When you shake it, these sulfides are released and get quickly oxidized -> pH drop.
You'll have to completely clean and rearrange your filter, I'm afraid. Sulfides are poisonous.

Ok, this is where my head was going with it, with much better words. It had to do with the opening of the filter, oxygenating areas that were operating on low to no oxygen, creating chemical reaction as you describe. Thank you! So I guess the purigen dunked bowl of water is due to the purgien 'grabbing' a bunch of the sulfides and then "leaching' the acidity into the fresh water. (although I'm sure the details aren't quite there and would be better stated by you, lol)

Ok, so now that we have the issue diagnosed, the matter of fixing it is now at hand. At least I know I am in the right place for it!

That being said, I have a Biomaster 350 Thermo. Up until yesterday when I added in the Purigen all it had in it was a boat load of Seachem Matrix. All my research led me to believe my goal was to pack as much bio media as possible (outside of the prefilter for mechanical), and that Matrix is a popular and effective product for this. Of course being the zealous beginner that I am I proceeded to pack each tray completely full. If my memory serves, I have over a gallon in there. My sneaking suspicion now that you mention this, is that I may have too much in there, and maybe I should begin my removing some? Perhaps that would help increase some flow both within the filter and without? I have been concerned I haven't been getting enough flow in the tank, but since I am a newb I really have no frame of reference for this, and "plants gently swaying" is a little subjective for me I guess. Outside of removing some matrix I don't know what else I could do. I cleaned the prefilter last week...

 

[Hufsa]

I dont really have a clear answer to what I think might have happened, but I just want to throw these thoughts out before I forget about em again;
Do we know that the amano shrimp were reacting in a bad way? Sometimes they get a bit giddy during a water change, especially if they feel like they can "swim upstream" where the new water is coming in.
Since you were the only one present, its only you who could guess if they were looking like something was hurting them, or if they were just feeling a bit spicy?

How confident are we in these PH measurements? Im sorry if I missed it (I have the attention span and memory capacity of a goldfish with alzheimers..) but what measuring device are you using, details?
KH and PH is not my best field but I think @dw1305 usually cautions about trying to measure PH in 0 KH water.

Your filter should not be needing to be tilted all the time, and after two weeks shouldnt really have a big cloud of guff and detritus worms coming out - in my opinion.
If possible can you go through how you have set up the filter and filter media, perhaps its getting air stuck somewhere and thats whats causing it to need these manual adjustments?

How does your filter media smell?

 

[Musicmanryann]

Hi @Musicmanryann I just visited your journal ... if I am not mistaken your tank is barely 14 days old!?

@_Maq_, to me it sounds somewhat unlikely to me that sulfides would build up that fast? I mean the flow through the filter would have to be almost absent.

Cheers,
Michael

I planted two and a half weeks ago, but I started with a dark start innoculated with 2Hr Aquarist APT Start bacteria three weeks before that. I also supplemented some Seachem Stability later on. The bio filter is almost 6 weeks old...

 

[MichaelJ]

How confident are we in these PH measurements?

This one!

KH and PH is not my best field but I think @dw1305 usually cautions about trying to measure PH in 0 KH water.

... and this one! (yes, you need lab grade equipment to measure pH reliably very near 0 KH).

How does your filter media smell?

... and, wait for it, this one! (filter would smell like rotten egg... not necessarily strongly so).

Cheers,
Michael

 

[Musicmanryann]

I dont really have a clear answer to what I think might have happened, but I just want to throw these thoughts out before I forget about em again;
Do we know that the amano shrimp were reacting in a bad way? Sometimes they get a bit giddy during a water change, especially if they feel like they can "swim upstream" where the new water is coming in.
Since you were the only one present, its only you who could guess if they were looking like something was hurting them, or if they were just feeling a bit spicy?

How confident are we in these PH measurements? Im sorry if I missed it (I have the attention span and memory capacity of a goldfish with alzheimers..) but what measuring device are you using, details?
KH and PH is not my best field but I think @dw1305 usually cautions about trying to measure PH in 0 KH water.

Your filter should not be needing to be tilted all the time, and after two weeks shouldnt really have a big cloud of guff and detritus worms coming out - in my opinion.
If possible can you go through how you have set up the filter and filter media, perhaps its getting air stuck somewhere and thats whats causing it to need these manual adjustments?

How does your filter media smell?

I think you already know me pretty well Hufsa, to second guess my observations and prevent me from jumping to conclusions. One thing is that during the time the amanos were jumping around my Zebra nerites were high-tailing it to to the water line also. You're right, though, this could all be a coincidence. I did do my daily water change right before also this also. I was also aerating the water during this as i was trying to remove excess CO2 from the water after i turned off my CO2.

I am using an Apterra PC60 pH meter. Not state of the art, but not economy.. I have thought about the probe being funky, so I guess if we look at relative values though, the pH shot down over a point. My alarm was that I was just reading about the shrimps not liking drastic changes to pH and obvs this was a pretty drastic change as far as I know. Also some reading about acidic water 'melting" nerite snails shells. I am just trying to take care of my new pets...

Don't know if the media smells...a good question...but...im kinda afraid to open it up now....🙃

 

[Musicmanryann]

If possible can you go through how you have set up the filter and filter media, perhaps its getting air stuck somewhere and thats whats causing it to need these manual adjustments?

See above--was writing it ass you posted.

Also thanks sooooo much to everyone for your help so far!

 

[Musicmanryann]

See above--was writing it ass you posted.

Also thanks sooooo much to everyone for your help so far!

I meant as, not a$$, now edit has timed out.

 

[LightingBamboozled]

I notice you said you topped up with straight RO water. What remineraliser are you using? What kH are you aiming for and how are you checking it? I think you said On May 4th in your journal your kH was 0. This will be a problem for your pH. You were also still having some Ammonia and I can't see that this has cleared. Some information on current water paramenters would help.

Filtration, if I read your journal correctly is an Oase Biomaster 350 Thermo with Chihiros/FZone replacement tubing. Filled with Seachem matrix and nothing else? It might be worth doing a flow check on it. Just get a container of known volume, lift the hose out of the fish tank and time how long it takes to fill the container. I'd expect to see 400 - 600 lph (111 to 166 ml/s filling 1L per 6-9 seconds). If it's signifiantly below that then flow is your issue and we need to see if there's a blockage in the filter or kink in a hose.
The critters sound like possibly detritus worms, but they should not be building up in your filter and hoses because they like low flow areas most of the time. If it were planaria it would be flat and it has an Arrow Head shaped head. Detritus worms get to about 2.5cm and they don't have a head and wiggle around pretty randomly. When the lights come on first thing in the morning do you see lots of them on the aquasoil?
They could be Tubifex worms but those would ususally be brown/red. They're not harmful per say. I would open the filter and check if they're growing in the media. A build up of these worms would suggest very dirty media indeed which would be unusual in such a new tank with no fish.

 

[_Maq_]

it sounds somewhat unlikely to me that sulfides would build up that fast?

All organic matter contains reduced sulfur (S2-, i.e. sulfide). In the presence of oxygen, the more so with the help of bacteria, this is oxidized to S6+ (i.e. sulfate). However, if sulfate gets into anoxic zone (in porous media, par example), sulfate respiring bacteria reduce it back to sulfides.
Now, I'm not sure if @Musicmanryann used some sort of aquasoil. If yes, then sulfide build-up could occur within a few days. Yet even without aquasoil it could happen rather easily. No matter what you do, in newly established tanks the amount of decaying organic matter is usually high. (I believe it has something to do with the fact that after replanting, plants are damaged, leaking sugars, dropping leaves and roots, etc.)

Up until yesterday when I added in the Purigen all it had in it was a boat load of Seachem Matrix. All my research led me to believe my goal was to pack as much bio media as possible (outside of the prefilter for mechanical), and that Matrix is a popular and effective product for this. Of course being the zealous beginner that I am I proceeded to pack each tray completely full.

That! You named it - it's a beginner's mistake. You've reduced the flow too much.
Seachem Matrix is a media explicitly designed to allow suboxic decomposition (denitrification). But it can support in inner zones anoxic decomposition (sulfate reduction) as well.
All your research led you... Well, that's a prevailing opinion. Believe or not, it all comes from manufacturers and vendors. Some members of this community may offer a very different opinion: What matters is oxygen. You should care to make your tank well oxygenated. Microbes will settle in substrate and virtually everywhere within the tank, and they will do their job as long as oxygen is present in sufficient concentration. Biofiltration in canister is redundant.
Perhaps you don't believe. In such a case, go the middle way: Reduce your media load in your filter to half. That will increase oxygenation both in the tank and within the filter.

 

[LightingBamboozled]

You've reduced the flow too much.

I don't believe we have established that. It may be the case but with a single bag of 100ml purigen I find it hard to believe they've significantly obstructed the flow of a Biomaster 350. Look at this vid from Geordie Scaper, the sachet barely covers half the surface area so even if no water was getting through the purigen it couldn't cut flow by more than half, which is still a lot of flow.

Seachem Matrix is a media explicitly designed to allow suboxic decomposition (denitrification). But it can support in inner zones anoxic decomposition (sulfate reduction) as well.

There has never been any evidence of any filter media supporting anoxic decomposition in a filter. There is simply too much flow of fresh water. Sulphate reduction needs nearly 0 flow such as within a sand bed.

Whilst we're trying to help a beginner diagnose two possibly related issues we shouldn't be diving into speculation. With clost to 0 kH in the tank there are lots of things that will cause pH drops and hydrogen sulphide isn't a likely one unless the filter has been turned off with 0 flow for a prolonged period.

 

[_Maq_]

It may be the case but with a single bag of 100ml purigen I find it hard to believe they've significantly obstructed the flow of a Biomaster 350.

I didn't mean that it was the sack of Purigen which restricted the flow, but the mass of Matrix.

There has never been any evidence of any filter media supporting anoxic decomposition in a filter.

Anoxic conditions are documented to exist within a single decaying leaf or within a snail's feces in otherwise oxidized water.

 

[dw1305]

Hi all,

KH and PH is not my best field but I think @dw1305 usually cautions about trying to measure PH in 0 KH water.

It is a bit of a strange one, but yes @Hufsa is correct, pH becomes more and more unstable as you move towards pure H2O.

I don't tend to worry too much about pH, it isn't that it isn't biologically incredibly important (it is), but because <"measuring it accurately is quite problematic"> and it can only be interpreted if you have some measurement of the <"carbonate content (dKH) of the water">. I actually use the <"Snail Shell Index"> as my pH proxy.

I'll be honest, nearly all the things that you'll read about <"pH stability and buffering are wrong">

The "problem" is really with the pH scale, which is both a ratio <"and a log10 scale">.

At pH7 you have an equivalent activity of both <"proton donors (acids) and proton acceptors (bases)">, but pH doesn't tell us anything about amounts, just that our "scales" are balanced.

To <"use an analogy">, it could be a grain of sugar in either balance pan, or it could be a sugar cube or a bag of sugar. As long as both scales have the same mass of "sugar" our pH remains at pH7.

cheers Darrel

 

[MichaelJ]

but the mass of Matrix.

From my experience with Matrix you can't really "pack it" that densely . Over time with build up of "waste" matrix can definitely clog up the filter, but only after 6 weeks? That just seems unlikely (not impossible) to me.

Here is a picture of the Matrix "pebbles" - id say they are about a cubic cm. of all sort of shapes.

Purigen on the other hand as it gets dirty can easily restrict flow tremendously in my experience. I think we are possibly looking a various different problems - possibly including lack of flow through the Bio Master 350.

Of course at a hard zero KH, pH can and will wander (measure) all over the place.... it's not a very natural thing and you really don't find zero KH in natural water ways... there is always some CO3 it seems. In both my tanks I keep KH at around 0.5.

Cheers,
Michael

 

[Musicmanryann]

I notice you said you topped up with straight RO water. What remineraliser are you using? What kH are you aiming for and how are you checking it? I think you said On May 4th in your journal your kH was 0. This will be a problem for your pH. You were also still having some Ammonia and I can't see that this has cleared.

Hey, thanks for your interest! I am using 2Hr APT Sky for my remineralizer. Only raises GH. Using Amazonia II Aqausoil, which at least for now sucks up any attempt to raise KH in any meaningful way. Others have stated it

Some information on current water paramenters would help.

It was in the quoted portion of the OG post: "What happened?? I have looked it up and seachem says Purigen doesn't alter water parameters. I currently have the bag of Purigen sitting in a bowl of water that has a pH of 4.35. That same bowl of water was at 5.85 before I added the bad of Purigen. I feel like this has something to do with my low kH (using Amazonia so KH is <1), but I really am at a loss. Another thought I had was when i opened the filter there were pockets of anaerobic activity in there and introducing a bunch of air disrupted that releasing Hydrogen sulfide (I did smell sulfur during my troubleshooting) . Here though, I am admittedly grasping at straws, and talking about things I don't know nearly enough about. Current parameters are Zero NH3, Zero NO2, less than 10 NO3. pH 5.25. (GH 7, KH <1) I have an aerator stone going hoping to add in as much O2 and remove as much CO2 as possible, but no idea if that is stupid or pointless or both. All I know is whatever happened it caused a very fast and drastic change to my pH. Any thoughts about what may have happened, and or what I may do to prevent it in the future would be more than welcome. It was a bit of a stressful saga. Lol."

7 is my target GH, and I say <1 KH because I cannot measure below 1 using API KH Test Kit. When I test it, one drop makes it change color. According to the test instructions (if I understand it correctly) that would give me a KH of 1, but since I am using RO water and Aquasoil I guess I infer that it is less than 1. The language I use in my journal I guess has evolved overtime to reflect that inference. To be clear, to the best of my tools and abilities, since I bbegan measuring KH I have only measured KH to 1 drop of API Test solution. I anyone knows a way I can be more precise below "1" I would love to incorporate that in to my testing.

Filtration, if I read your journal correctly is an Oase Biomaster 350 Thermo with Chihiros/FZone replacement tubing. Filled with Seachem matrix and nothing else? It might be worth doing a flow check on it. Just get a container of known volume, lift the hose out of the fish tank and time how long it takes to fill the container. I'd expect to see 400 - 600 lph (111 to 166 ml/s filling 1L per 6-9 seconds). If it's significantly below that then flow is your issue and we need to see if there's a blockage in the filter or kink in a hose.

Thanks for giving me a method to reliably measure flow! After a few failed attempts at gaining an accurate measure, I filled one liter from my filter outflow in between 6.5 and 7 seconds.

The critters sound like possibly detritus worms, but they should not be building up in your filter and hoses because they like low flow areas most of the time. If it were planaria it would be flat and it has an Arrow Head shaped head. Detritus worms get to about 2.5cm and they don't have a head and wiggle around pretty randomly. When the lights come on first thing in the morning do you see lots of them on the aquasoil?
They could be Tubifex worms but those would ususally be brown/red. They're not harmful per say. I would open the filter and check if they're growing in the media. A build up of these worms would suggest very dirty media indeed which would be unusual in such a new tank with no fish.

Google image verified they are detritus worms. I had not observed them until the day the cloudy stuff came out of the filter after I agitated it. I saw them in the current of the water. Have seen a couple wriggling around the soil since. It very well could be they were in the water before this occurred, and I observed them because I was looking closer at the water because it was just polluted--they are tiny. I can't be certain though....

 

[Musicmanryann]

I don't believe we have established that. It may be the case but with a single bag of 100ml purigen I find it hard to believe they've significantly obstructed the flow of a Biomaster 350. Look at this vid from Geordie Scaper, the sachet barely covers half the surface area so even if no water was getting through the purigen it couldn't cut flow by more than half, which is still a lot of flow.

I used Geordie Scaper's video to help set it up. I did use more Purigen than 100ml, but it was in the filter for maybe twenty minutes.

With clost to 0 kH in the tank there are lots of things that will cause pH drops and hydrogen sulphide isn't a likely one unless the filter has been turned off with 0 flow for a prolonged period.

Would love to know other ways the pH drop could occur. Filter definitely hasn't been off for a prolonged period. Only to do my water changes for about 10-15 minutes maybe at a time.