SunSun 303b on a 40 breeder.

Tray 1 (bottom): Coarse blue sponge, Marineland blue bonded pad, white polishing pad designed for 303b trays, and topped off with a 100 micron felt pad.
Tray 2 (middle): Seachem Matrix, a bag of seeded Fluval Biomax for quickly establishing new filters (if necessary), and 250ml of Purigen.
Tray 3 (top): 1 lb of Biohome Ultimate.

I usually go about 5 weeks (first weekend of every month) between filter cleanings, but the last one I went 6 or 7 weeks, and probably could have gone longer. But I try to keep my routine relatively consistent, it's just the last cleaning I got kind of lazy about getting done on time.

Anyone use pot scrubbies for bio media? I'm trying it out since I'm on a tight budget. Got the idea from here: https://www.monsterfishkeepers.com/f...o-media.46922/

I think The King of DIY (Joey) on youtube made a video about cheap bio media. Pot scrubbies and lava rocks are mentioned in the video.

My idea was to leave it in, if it can lower the pH little by little, that is essentially what I want. If it drops by really quick, then, wouldn't that be considered an issue?

Doesn't in my experience. It's relatively mild stuff in terms of any effects and takes some time. That may vary some depending on volume/water volume, buffering within your tank, etc., but in general it's not going to cause any shock in any typical use. You can leave it in but at some point whatever's in there that can be extracted will be extracted and it won't be doing much for you from there.

Absolutely you can move what is in your existing HOB media into your new canister filter. Beneficial bacteria will grow on nearly everything in a fish tank - granted it "prefers" to grow on some things more than others. Based on some of my previous experimentation, beneficial bacteria grow very well in sponge material (think sponge filters). Once your have your new filter set up, give it a week or so of run time for the HOB bacteria to grow into the canister filter bio material. Then I would slowly (over 2 weeks or so) remove the HOB material.


As for the new filter, yes it does mater how you set up the trays. Bio Media typically does the best in clean water (think well filtered). So, most canister filters move the incoming water to the bottom of the filter. As the water moves UP thru the trays you want to progressively filter out the debris - course to fine. Then at the very top of the filter (top tray) is where your bio media goes.

Plants also uptake nitrate and ammonia, and at least with my bioload, it's possible for me to bottom out on nitrate in the tank during the week as long as the plants are growing well even with fertilizers being added that contain it. It's not like nitrate is running amok in my tanks. And nitrate is only one reason to do water changes.

I am also just a bit dubious of marketing approaches that could be called a form of "negging". Such as the "you aren't fully cycled unless you use biohome" line. I'm not losing sleep over my nitrate levels or water change frequency, any water quality issues I do have are not going to be solved by it, and biohome isn't offering up evidence of effectiveness, I'm okay with what I've been using.

Say you have an EI dosed, high tech tank, that gets the weekly 50% water changes. Would the pH shift from tap (say 7.4-7.6) mixing into the buffered water be a shock to the fish?

Way too many variables and unknowns to say. Best that I can tell you that I've not seen any sort of shock-type effects in any of the tanks where I use it. That's doing regular 20-50% water changes and nothing to pre-treat the new water (other than Prime obviously). Mostly used in tanks with rams and some other fish that are at least somewhat sensitive including many times with fry in the tanks which I'd think would be a pretty good worst-case.

Have you measured the pH before and after to see what the swing is?

In fact I did monitor pH when I first started using it to see what effect the peat had but I couldn't tell you now exactly what it was for an N% water change. About as expected as I recall. My tap is about 7. Over about a day or so it will take it down to the ~6.5-6.3 range. Water changes left it somewhere in between and then it would slowly bottom out again in that same range. As I said, never had any issues and my tanks are relatively stable at this point so haven't really paid much attention to it beyond that. Main reason that I started using it was to get pH lower for successful fertilization of ram eggs and they spawn all the time so I can kind of monitor it indirectly that way. On the odd occasion that I've tested it otherwise it's always in about that same range.

It's healthy and wise to be skeptical. But, I assure you, this media works.

Glad you aren't losing sleep over doing frequent water changes; but I'm not in that camp. I prefer the low-tech/no-tech/Walstad approach that advocates less water changes. And my water quality is just fine.

What evidence of effectiveness do you require before trying it? The microbiology, behind how anaerobic bacteria break down nitrates and release nitrogen gas, is not in dispute here; it's part of the (complete) nitrogen cycle. It's basic chemistry.

It took about 4 months, for the anaerobic bacterial colonies to fully take hold in my tank's media, but once they did, it was remarkable to witness my nitrates plunging to almost zero and staying there, for months and months on end.

I also just set up a 4 gallon Walstad tank, this last month. (Plants haven't grown in yet.) I was regularly dosing 4 PPM of ammonia, which kept my nitrates at 20-40 PPM. When I finally added some established Biohome Ultimate media, from another of my tanks, the nitrates plunged to 0-5 PPM, in 4 days... 4 days. And it's stayed there, day after day after day, despite daily dosing of ammonia.

Of course, heavily-planted tanks, with faster-growing plants, can keep ammonia and nitrate levels low too (that's also basic chemistry), but not all people's tanks have such a high plant filtering capacity v.s. their bioload. So, for many of those folks, those elevated nitrate levels is a major reason for frequent water changes.

Anyway, keep on doing what works best for you.

Best,
D

But that isn’t the start and end of the reality is it? Those bacteria need specific conditions, which generally aren’t found in canister filters. It’s even recommended to keep flow slow around this media, as well as a larger amount of it for denitrification, which already suggests a YMMV factor here. But without any solid details it’s hard to say anything solid about it, or validate the claims beyond anecdote.

When this process happens in our substrate, it’s possible for the bacteria to get nitrogen starved and turn to producing hydrogen sulfide. Can the media clog, causing similar conditions after long term use? Why or why not? Not really discussed either. At least vaguely it should be fine, but not a lot of data to draw solid conclusions from, either.


And while this is an interesting anecdote, it isn’t the same as data. Not without being able to eliminate other factors, and causes. Key to that is a good control.

An example is BRS attempting to test if Marine Pure had denitrifying properties. Their tests were inconclusive, partly because all tanks in their test saw a period of very low nitrates before seeing a rise in nitrates, even their control with no media which plunged down before rising back up.

At the end of the day, what I have been using works, and I’m not terribly interested in doing a 6 month long test of media where the sole benefit is to compete with my plants for nutrients. In the time it takes this stuff to establish, you should also be getting plants established with similar nitrogen controlling benefits. So our planted tanks aren’t exactly great for controlling variables, as we intentionally add more.

I will point out that Seachem does make similar claims with Matrix, just not nearly as vocally as biohome does.

I just bought Biohome Ultimate media. I'm going to change it next canister cleaning. Figure I'll add it in it's own little bag next to existing media for a while. I'm also going to add a different sponge along with the Eheim sponge.

I'm going to experiment with pH, I have peat granules in a bucket with water out of tap, 7.8, letting it sit for a day and then check.