Black Algae Growth okay? No green algae?

[blubird101]

Hello! So here's a little preface to the situation....

So I currently have a 3 gallon tank setup for my opae ula. I only have two in there right now (I liberated them from an ecosphere type enclosure I had before. I used to have 5 in there, but they slowly whittled down to just 2 as I was told like everyone else that..."they only live like 5 years!" I now know that to be false and have changed my ways haha.) but I plan on getting some more.
Now I set up my tank several months ago, and its got lava rock and some sea fans. When I first set it up, I waited until I saw some algae, and pretty quickly the lava rocks started to get a dark, almost purply black growth on them. (its not furry or anything, its almost like the rocks are just colored differently now.) I also got some biofilm on the water and some green algae on the glass.
I checked levels and everything looked good, so I added in my shrimp. They've been doing great since then! The algae on the glass was a little much for me though, so I added 2 nerite shrimp. They tend to stay on the glass, so they quickly cleaned the glass and have been happily motoring around the tank as well.

Since then, I haven't noticed any green algae growth or new algae growth. The dark coloring on the rocks hasn't changed, and any snails that go on there can't seem to eat it off. The two shrimps are thriving though, and are now a happy red color and look to have the...dark color? in their tails, showing their bellies full of food haha.
The snails are also doing great. Levels are still fine. So I'm wondering, what kind of algae is this? Is it even algae? Should I be concerned that I don't show any regular green algae growth?
I recently flipped some of the rocks over that weren't above the substrate, and they still have the bright reddish color they started with, and haven't had any of that algae grow in yet. I'm kinda sad cause now my tank is super dark looking since my substrate is black haha. I liked the red color of the rocks and I was hoping for the green algae to compliment that...haha
Quite puzzling.

I've attached some pictures of the setup and shrimp. (the tank on the left is my betta tank haha. Don't mind the painting supplies )
Any help?

[i<3Opae]

The water looks clear and the shrimp are doing fine, so I don't think the algae on the lava rock is of any real concern. You might not see visible algae now elsewhere because of the nerites, they have a big appetite.

[Mustafa]

Thanks for sharing your story! One thing I noticed is that you seem to have what looks like some kind of freshwater shrimp substrate ("soil") in there. is that correct? If so, I would take it out. It is designed to "eat up" alkalinity and, due to that, drastically decrease the pH. These are all bad things for our Supershrimp. How long have the shrimp been in there?

[blubird101]

Okay, i've just never seen this kind of algae so I was wondering if anyone knew what kind or if it even is algae? haha
And Mustafa, yes, technically it is Fluval Stratum substrate, although when I measure my PH it looks to be around 7.6, is that too low? The tank has been up and running since late September

[Super Jess]

Mustafa said in this thread that "Usually the pH should be around 8.1-8.2 and alkalinity around 140 or so after mixing up your brackish water."

[Mustafa]

As Super Jess pointed out in the link...your alkalinity is way too low, which directly affects your pH, which is also too low. Your shrimp will start dying once your alkalinity is almost gone and your pH is around 7. That's a direct consequence of the freshwater shrimp "soil" you used. It neutralizes alkalinity by releasing acid(s). Those soils are almost completely organic (as opposed to minerals) and continue breaking down over time and lowering alkalinity (kh). They basically become "mud" or least "mushy" at some point. Since we usually aim to have a stable environment and plan to keep our shrimp for years and decades, it's not a good idea to have an acidifying substrate that will be mud at some point. I would take it out. Just my humble opinion.

[marianne]

Hi blubird

I could be completely wrong, but on the side of the "black algae".. it seems that it developped on the exposed sides of the rock only. Can you remove it from rock at all, by scrubing ? If not... To me, that looks a lot like oxidation of iron, and the lava rock are quite rich in it so it's not impossible. What makes it more plausible is that your pH is low, so could definitly fasten the oxidation process.

I would say it's an additional reason to follow Mustafa's advice.

[blubird101]

Ah okay! I was looking all over for the correct PH and was never able to find a concrete answer, so thats super helpful. I'll definitely change it out.
I'll have to take everything out to change the substrate. Will taking out all the substrate mess with all my parameters? (essentially starting over?) Should I take the shrimp out while I do so?

And Marianne, that actually sounds more accurate as it is only on the exposed sides, the sides facing the light. I tried to scrub it off any only a little bit of it comes off, its still dark. I figured this is because its such a porous surface that I couldn't get all of it off, but I think your definition makes more sense.

[blubird101]

Also, in searching for a suitable substrate, can any inert sand work? I found a sand that is 100% calcium carbonate, no silica, no phosphate. (its not a "live" sand that is meant for planting either) I read that calcium carbonate provides calcium and helps to keep that PH safe, I believe that's why its sold here, So would that work?
Also, is there a way we can provide a simple "getting started guide" that's stuck to the top of the forum or located under the FAQ? The FAQ above only links to ordering type questions for the store. I found a "how to set up your shrimp tank" guide at one point, but haven't been able to find that again. It would be nice to have a good reference for what parameters I need. (ex., temperature, PH, alkalinity, GH, KH, Nitrate, Nitrite, Ammonia, ect.) so I don't make mistakes like this again! I only really see mention of salinity and the other parameters I have to dig around on the forum for (and its hard to find a concrete answer). It would be great to have one page just linked to the top with that info. I'm sure its been done before, but if it was, its lost in all the different discussions. Just a suggestion though!

[SailorFromRI]

Here is the link to the step by step guide.

https://www.petshrimp.com/set-up-a-supe ... tructions/

[blubird101]

Ah yes, thats the one! I wish it went into more depth though on parameters like I mentioned, thank you though!

[SailorFromRI]

Yea I understand. Once the tank is cycled you should see nitrite and ammonia readings of zero. That's really what we care about. I am going to start a new tank to move my shrimp to in the next week or so. Maybe I'll do a detailed thread on the cycling process, daily test results, algea growth, timing etc.

[blubird101]

Any advice on my question earlier on suitable substrate?

[SailorFromRI]

Calcium carbonate would work fine. I am setting up a new (glass) tank and I'm planning on using this black sand just because I like the look. I thought about using CC sand too but will use some old coral skeletons I have lying around to buffer PH. Have u tested ph or alk? How are the tank/shrimp doing?

Imagitarium Black Aquarium Sand, 5 lbs (5lb) https://www.amazon.com/dp/B073DY8KZX/re ... DCbSZS4S8Z

[Mustafa]

Also, in searching for a suitable substrate, can any inert sand work?

As long as it's really inert and you wash it well, it should be fine.

I found a sand that is 100% calcium carbonate, no silica, no phosphate. (its not a "live" sand that is meant for planting either) I read that calcium carbonate provides calcium and helps to keep that PH safe, I believe that's why its sold here, So would that work?

Is it sold for aquarium use? Stay away from reptile sands. It's hard to say what really is in it. Plus the companies don't have to be that careful for reptiles as they have to be for fish/shrimp.

Also, is there a way we can provide a simple "getting started guide" that's stuck to the top of the forum or located under the FAQ? The FAQ above only links to ordering type questions for the store.

The step by step instructions were linked to below. I want to keep the top of the page rather simple. That's why I put "SUPERSHRIMP!" up there, capitalized and with a exclamation mark so that people don't miss it. That's supposed to be the first link to click and explore. The step by step instructions are there and other information too. There will also be a "Supershrimp FAQ" soon, as you are correct about the current FAQ not being useful for beginners at all. It's just helpful for people thinking about ordering from Petshrimp.

I found a "how to set up your shrimp tank" guide at one point, but haven't been able to find that again.

SUPERSHRIMP!

It would be nice to have a good reference for what parameters I need. (ex., temperature, PH, alkalinity, GH, KH, Nitrate, Nitrite, Ammonia, ect.) so I don't make mistakes like this again! I only really see mention of salinity and the other parameters I have to dig around on the forum for (and its hard to find a concrete answer). It would be great to have one page just linked to the top with that info. I'm sure its been done before, but if it was, its lost in all the different discussions. Just a suggestion though!

I didn't put up any parameters on purpose. I have not measured any parameters in my Supershrimp tanks (except maybe salinity once in a while when I fill up my tanks after water evaporates) in almost a decade, maybe more. You're not supposed to worry about the parameters when you follow the instructions here. The whole point of the "Petshrimp method" is that it's dead simple. Just set it up and forget it. I did say in the instructions that the substrate should be inert, but in my next revision I will make it more clear that no acidifying "shrimp soils" or substrate of unknown composition should be used. Keep in mind that many new Supershrimp keepers have *never* had an aquarium. They should not have to worry about any kind of parameters. Having said that, there is no need to measure because if you have an inert or calcium carbonate substrate, a pH buffer (calcium carbonate rocks, cc substrate etc) and follow all other instructions in the article, things don't usually go wrong. I actually advise that people do *not* buy any testing equipment, so they don't obsess and drive themselves crazy thinking there is some magical "perfect" parameter that they need to be chasing. These shrimp are all about keeping it as simple as possible.