Dark Start Method - avoid algae and melting plants

[Art]

My friend, Jurijs Jutjajevs, a professional aquascaper from Germany and old co-host of the ScapeFu Podcast with me, has released a high-quality YouTube video describing the dark start method. It's a method for starting your aquarium by first building a biological base (cycle the tank) before adding plants. I used this method in my latest build.

Enjoy!

 

[*Ci*]

A couple of questions that were not addressed in the video. He mentioned a minimum of two weeks - how do you determine when the dark start is done? Should you be testing ammonia and nitrite throughout the process as you do with other cycling methods?

It was mentioned that this method would work well for inert substrates as well as active ones, but do you need to add bottled ammonia if using an inert substrate (which would also imply testing)?

I assume when the process is over, you do a 100% water change to remove tannins and high nitrates and then plant? Do you then immediately add co2 and start fertilizing? I will be using inert gravel with small pockets of ADA Aquasoil in a nano tank.

Thanks for any advice!

 

[Zeus.]

James Finley profesional aquascaper who use to own The Green Machine. Did lots of utube vids for the hobby. He used the dark start in the tanks he did, although its not mentioned in the vids. Got most of my hardscape rocks from Green Machine so got all the info from his guys.
Think he use to leave them 6weeks, AS and rocks in,filter on, no lights or CO2.
Then drain tank substrate level then plant the whole tank fill.
Then tank,substrate and filter was cycled.

 

[Yugang]

These video's are funny, in the first minute he says twice that it is completely free, and then just in the second minute recommends 2Hr Aquarist APT Start to kick start the process Not saying it does not work, but like other products with bacteria not much evidence published regarding efficacy. Good for newbies, maybe, but for more experienced hobbyists like yourself @*Ci* probably not the most pragmatic.

Here is what I would do, but I know that there are others on this forum more experienced with starting tanks. I know that @Tim Harrison usually cycles his tank in less than 2 weeks, so he may have some further advice.

You are using mostly inert substrate, and just a little aquasoil. So most likely some ammonia spike from the AS, good food for the bacteria but not too much really. You also have existing tanks, and probably filter material. I would use the gunk, or perhaps even filtration material from an existing tank to kick start the microorganisms in the new tank. From what I have read, you may very well have the new tank cycled within a week or two, as to be confirmed with testing ammonia and nitrites. Time to turn on the light, water change never does harm, and you may then want to add some faster growing plants first. Start fertilising and CO2 now. Do one more check on ammonia and nitrites later before you want to add any livestock and more sensitive plants.

I believe the above makes sense, and just pragmatic. No need to overthink the process, or go shopping, just use what you already have in your existing tanks.

 

[Jeff Miotke]

James Finley profesional aquascaper who use to own The Green Machine. Did lots of utube vids for the hobby. He used the dark start in the tanks he did, although its not mentioned in the vids. Got most of my hardscape rocks from Green Machine so got all the info from his guys.
Think he use to leave them 6weeks, AS and rocks in,filter on, no lights or CO2.
Then drain tank substrate level then plant the whole tank fill.
Then tank,substrate and filter was cycled.

I thought the same exact thing…Green Machine! And also reef guys with real live rock back in the day did this too. Funny how these things pop up from the past as new.

 

[gnatster]

Reviving this...

I've watched probably a dozen videos and read a few articles on the Dark Start methodology. I'm about to embark on this journey.

Referencing this even older thread on the topic has these steps.

The 10 steps are basically very simple to do the "dark start" method:

1. Position all of your aquarium equipment
2. Add the substrate and hardscape
3. Flood the tank with treated tap or RO water
4. I recommend adding a bacterial starter bottle such as Dr. Tim's or Fritz Turbo
5. DO NOT turn on the lights
6. Turn on the filter - no CO2 needed (obviously)
7. Test water to make sure there is ammonia
8. Wait and test water like you would through any cycle (NH4, NO2, NO3)
9. Once NO3 is present, 90% water change
10. Plant and proceed as usual

Some questions.

RE #3: If using RO, remineralize or not?

The 2hrAquarist recommends soaking the contents for 2-3 days with the filter off. Performing a 100% water change and proceeding with Step #4. Thoughts on this? (Aside, I'm in no hurry)

RE #9: Many sources recommend testing a day later to see if NH4 is present; if so, keep it dark, if not, plant (draining to facilitate the planting process appears optional. Some did, others did not. Personal preference.

There is discussion in this and other threads where supplemental PO4 is added during the Dark Start phase. Can someone please elaborate more on this? TIA

Is there any advantage to covering the aquarium to black it out fully?

 

[Kwyet]

I think some phosphate and mineralization helps with cycling.

 

[Naturescapes_Rocco]

RE #3: If using RO, remineralize or not?

I would remineralize, as you want the system/soil/bacteria to be as "stable/ready" as possible upon introducing plants and light. Sudden changes in water chemistry after weeks of allowing it to mature would be almost counterintuitive!

The 2hrAquarist recommends soaking the contents for 2-3 days with the filter off. Performing a 100% water change and proceeding with Step #4. Thoughts on this? (Aside, I'm in no hurry)

I might misunderstand this, but I don't understand why you wouln't keep your flow/filter on the entire time. For reference: in my latest journal, I did a ~3 week dark start and had the filter on the whole time, with only one massive 90% WC when it was cycled/ready for plants (ammonia at or near zero).

RE #9: Many sources recommend testing a day later to see if NH4 is present; if so, keep it dark, if not, plant (draining to facilitate the planting process appears optional. Some did, others did not.

I did not wait for 100% of my ammonia readings to reach zero before I planted. After 3 weeks, I had built up plenty of NO3 (almost 50ppm if not more) and my ammonia readings had gone from very high to very low, but not zero. It would probably be safest to wait until there are basically 0ppm NH4 readings, but as long as it's clear the cycle is established, your plants will consume that NH4 within the first 2-3 days no problem (I wouldn't add fish until readings do reach zero, however).

There is discussion in this and other threads where supplemental PO4 is added during the Dark Start phase. Can someone please elaborate more on this? TIA

My guess is this is to help saturate your aquasoil (if that's what you're using) with PO4, because it not only doesn't have a lot of it, it will consume it and give you false-zero readings. You will see that dosing 2ppm PO4 in an aquasoil-based tank will show readings of 0ppm PO4 within a few hours as the substrate consumes it. I don't think this is necessary, but it technically wouldn't hurt anything especially with a 90% WC at the end of the dark start period. I do not do this.

Is there any advantage to covering the aquarium to black it out fully?

Sure is! You continue to prevent the development of even microbial algae growth. I would recommend just taping garbage bags around your tank for the dark start (so you can just use/reuse the bags for your actual household trash later). Many folks don't realize that algae spores can and will still grow in ambient room light. Blacking it out fully just gives your future plants an even better leg up on your system -- however, I did my large tank with blackout garbage bags, and a smaller tank without. Both cycled in ~3 weeks and had very little algae issues, so I wouldn't say that it's required to black it out fully (just recommended).

 

[PeerUnk]

My common sense tells me that a dark start (no lighting) helps prevent algae from getting established, giving microbial life a chance to develop first. I assume that microbes need the same basic elements as plants—NPK and trace minerals—so I plan to remineralize RO water lightly to support them. Adding a bit of "gunk" from an established filter or substrate should help even more, since it contains both nutrients and beneficial bacteria. A full blackout should also be best/effective at suppressing algae, since most species need light to grow or germinate.

 

[Pepere]

I have done it in a few tanks now and find it reduces the intensity of the Ugly Duckling stage.

If using Aquasoil, or Safe T Sorb, I dose frequently with phosphates to 10 ppm and test every other day residing as necessary until the substrate is filled up and stops. absorbing.

With inert substrate I dose to 2 ppm phosphate as it helps the bacteria grow. Also add declorinator and if kh is below 3-5 I dose baking soda as well to raise it to that temp. Finally I dose ammonia to 2 ppm. Then I wash out the media from a canister filter in the tank water.

Note ammonia loses potency even if it does not lose smell. Even in a sealed bottle. I got a bottle of Fritz Fishless fuel that had no ammonia present in it. I hold tank at 80 degrees until cycle is completed

So yeah test your ammonia levels a few hours after dosing after it has mixed.

I test daily for ammonia and nitrites. 2 ppm of ammonia makes around 5 ppm nitrites. If ammonia has been cleared more than3 days and nitrite is still present I drain to substrate and repeat everything.

A couple times every day I stir the substrate with a long handled spoon to respond mulm and let the filter take it up.

I keep draining and repeating until I get to the point where I can dose 2 ppm ammonia and it converts to0 Ammonia, 0 nitrites in 24 hours.

With good seeding this takes me about 2-3 weeks. Then a drain and refill, dechlorinate, add GH if needed and turn heaters down. I do not bother adding GH when tank is cycling.

I am not as concerned about fish bioload as I am about bacteria maturity in the tank for less algae issues.

No lights on other than when working in the tank, but no effort to black out ambient light.

 

[gnatster]

I might misunderstand this, but I don't understand why you wouln't keep your flow/filter on the entire time. For reference: in my latest journal, I did a ~3 week dark start and had the filter on the whole time, with only one massive 90% WC when it was cycled/ready for plants (ammonia at or near zero).

From the 2hrAquarist article,

"After filling the tank, we recommend letting the tank soak for a couple of days without running the filter. On the second or third day, do a 100% water change then start running the filter. This removes organic debris, dust and sugars released from the woods and prevent the filter from taking up a lot of debris at the start."

My guess is this is to help saturate your aquasoil (if that's what you're using) with PO4, because it not only doesn't have a lot of it, it will consume it and give you false-zero readings. You will see that dosing 2ppm PO4 in an aquasoil-based tank will show readings of 0ppm PO4 within a few hours as the substrate consumes it. I don't think this is necessary, but it technically wouldn't hurt anything especially with a 90% WC at the end of the dark start period. I do not do this.

I'm using UNS Controsoil substrate. I'm admittedly a bit lost on dosing PO4. Dose with Seachem Phosphorus OK? The aquarium is not that large, at ~10 gal/38l. Will I need to be testing and adjusting PO4 regularly during the Dark Start phase? Can ya'll please recommend a test kit?

 

[Pepere]

Will I need to be testing and adjusting PO4 regularly during the Dark Start phase? Can ya'll please recommend a test kit?

Api makes a phosphate test available on Amazon.

Rotalabutterfly.com helps you calculate how much phosphate compound to dose…

I did a 20 gallon with Amazonia 2 and I was amazed how quickly a 10 ppm dose would dissapear being soaked up in the soil…

 

[Naturescapes_Rocco]

From the 2hrAquarist article,

"After filling the tank, we recommend letting the tank soak for a couple of days without running the filter. On the second or third day, do a 100% water change then start running the filter. This removes organic debris, dust and sugars released from the woods and prevent the filter from taking up a lot of debris at the start."

I see! That makes sense, but doesn't need to be much of a concern as long as you have good filter sponges and are willing to clean it up at some point during the dark start cycle.

I'm using UNS Controsoil substrate. I'm admittedly a bit lost on dosing PO4. Dose with Seachem Phosphorus OK?

Like @Pepere said, use Rotala Butterfly Nutrient Dosing Calc.

You can use something like Seachem's Phosphorous (KH2PO4) liquid fert, or you can DIY it yourself with dry KH2PO4. Cheaper and more control IMO.

I use 1lb of GLA Fert's KH2PO4 for $8.

To reach 10ppm in my 140 gallon aquarium with dry KH2PO4 salts looks like this in Rotala Butterfly:

I input the volume,
select DIY,
select KH2PO4 (make sure you don't accidentally select K2HPO4, which is different!),
choose Dose to reach a target
add the target ppm (in my case, 10ppm)
then click calculate.

The results on the right say that "To reach 10ppm PO4 in my 140 gallons of water, I need to add 7.59g of KH2PO4". You can (and often should) ignore the comparison chart on the bottom of the calculator. Just focus on the results it tells you in text.

The aquarium is not that large, at ~10 gal/38l. Will I need to be testing and adjusting PO4 regularly during the Dark Start phase? Can ya'll please recommend a test kit?

You don't have to test for PO4 at all during the dark start. 99% of aquarists doing a dark start will not do that. You also don't need to saturate your substrate with PO4 dosing before you add plants, though you can!

What I'd recommend is this: Do your dark start and maybe add 4ppm PO4 at the beginning to help the cycle along a little, or don't. Either way your bacteria will grow just fine with Controsoil, if given 3-4 weeks without light but with water flow.
Don't stress about adding PO4 at this time. Add PO4 when you're ready to add PO4, when the plants need it! You can learn to use Green Spot Algae as an indicator for when your PO4 has bottomed out, and start dosing more then.

You could, optionally, start dosing 2-4ppm PO4 every 2 days, and measure with a test kit. It will likely show 0ppm by the next day, as your soild has absorbed it. Once you start getting readings of >0ppm PO4, you can stop dosing. But like I said, the vast vast majority of users don't do this (I don't) and you can add the PO4 later when you are fertilizing for your plants.

 

[Art]

"After filling the tank, we recommend letting the tank soak for a couple of days without running the filter. On the second or third day, do a 100% water change then start running the filter. This removes organic debris, dust and sugars released from the woods and prevent the filter from taking up a lot of debris at the start."

I call this "waterlogging" and I consider it to be different than a DSM. It allows everything to soak in water and any debris/sugars/etc will be released into the water column. You typically will see the film of gunk floating on the water surface.

If the substate will leach out any ammonia (used to be an issue with AquaSoil), then this may allow it to leach out first and then remove with the large water change. I'm not sure.

I am not a fan of this because it creates an anoxic environment in the aquarium. I don't see the need for this as I usually will run the filter with only mechanical media for the first few days. The media captures much of the debris. I swap out the media and install the biological media then.

Like others have said, dark means dark. If you can black it out with garbage bags, it's better.

As to whether to try to saturate the substrate with PO4, that's more of a personal decision for you. I don't like how it impacts my dosing initially so I normally do go through the substrate PO4 saturation.