Plastic rock vs Dry rock Testing

[Sprinter70]

Hey everyone, I’ve been working on a design for plastic rocks that should promote greater microbial colonization. I want to test this in a meaningful way and figured I would see what everyone thought would be a good experimental design. I have 2 2.5 gallon tanks and an imagitarium black dry rock that is about the same size. I have adjustable heaters that I can set to the same temperature as well as 2 of the same water pumps to circulate water in the tanks. 

Things I need to figure out:

1-How should I measure time to cycle? I have api nitrate and api ammonia test kits. How often should I test both tanks?

 

2-Should I seed bacteria? I think I should since it would reduce noise from chance microbe inoculation from the air. I can dose equal parts and do a water swap between the tanks at setup to ensure uniform starting points.

 

3-Should I feed the tank and if so what should I feed? I have some fish food and coral food (reef chili) I could weigh out and add the same to each tank. Open for thoughts there.

 

4-Did I miss anything that should be considered?

[banasophia]

Sounds interesting! I personally would probably use Dr. Tim’s because it takes a little longer than Fritz and BioSpira so you might be able to better tease out a potential difference in the performance of the two scapes. I would do a fishless cycle and use Dr. Tim’s ammonia drops rather than fish/coral food since it will be more exact. Not sure how often to test, but I’d probably do daily for more data points rather than every couple days. 
 

Also, tell us about your control dry rock and why that rock was chosen… I think you mentioned a black rock from Imagitarium… never heard of it, so I’m not sure whether that would be the best control? 

[Sprinter70]

1 hour ago, banasophia said:

Sounds interesting! I personally would probably use Dr. Tim’s because it takes a little longer than Fritz and BioSpira so you might be able to better tease out a potential difference in the performance of the two scapes. I would do a fishless cycle and use Dr. Tim’s ammonia drops rather than fish/coral food since it will be more exact. Not sure how often to test, but I’d probably do daily for more data points rather than every couple days. 
 

Also, tell us about your control dry rock and why that rock was chosen… I think you mentioned a black rock from Imagitarium… never heard of it, so I’m not sure whether that would be the best control? 

Okay, and you think testing for ammonia or nitrates would be best? 
 

the rock is just like the life rock stuff, but black so it is closer to the colors of my rock. I do not know if the color would matter, but looked around for a while to see a black rock about the size I needed.

[mcarroll]

5 hours ago, Sprinter70 said:

Hey everyone, I’ve been working on a design for plastic rocks that should promote greater microbial colonization. I want to test this in a meaningful way and figured I would see what everyone thought would be a good experimental design.

I'd like to understand the goal better.  You mentioned "greater microbial colonization".   Greater than what?  Are you trying to use plastic in a manner similar to bio-pellets?  Can you explain more about what you're trying to achieve?

[banasophia]

1 hour ago, Sprinter70 said:

Okay, and you think testing for ammonia or nitrates would be best? 
 

the rock is just like the life rock stuff, but black so it is closer to the colors of my rock. I do not know if the color would matter, but looked around for a while to see a black rock about the size I needed.

Yeah as far as cycling I would test ammonia nitrite and nitrate. But tbh, I always put seachem matrix in my tanks in the back chambers for extra surface area in addition to my rock, so if I was considering buying plastic rock it would be based more on appearance, whether there was a risk harmful stuff would leach out into the water, and whether corals and other things could grow and thrive on the rock. 

[banasophia]

Check out @NanoRox here and Instagram… he does some really awesome artificial rock scapes and may have some helpful insights on making your own rock. 

[Sprinter70]

1 hour ago, mcarroll said:

I'd like to understand the goal better.  You mentioned "greater microbial colonization".   Greater than what?  Are you trying to use plastic in a manner similar to bio-pellets?  Can you explain more about what you're trying to achieve?

It’s just a way to increase the surface area, kinda like bio pellets except built into the aquascape. Think pukani dry rock on steroids with the added benefit of custom design too. I’m having good results in my pico reefs from 1 gallon to 3 gallon, but did it out of convenience. I want to see how it performs compared to typical dry rock and cycling time is logically the first step.

[Sprinter70]

4 hours ago, banasophia said:

Check out @NanoRox here and Instagram… he does some really awesome artificial rock scapes and may have some helpful insights on making your own rock. 

Looks pretty sweet! So much detail and skill there!!!! I’ve been focused on what is going on in the core of the rocks, I have figured the coral will cover the rest. Will try to reach out and see how he does his base building for sure!

[Sprinter70]

4 hours ago, banasophia said:

Yeah as far as cycling I would test ammonia nitrite and nitrate. But tbh, I always put seachem matrix in my tanks in the back chambers for extra surface area in addition to my rock, so if I was considering buying plastic rock it would be based more on appearance, whether there was a risk harmful stuff would leach out into the water, and whether corals and other things could grow and thrive on the rock. 

This is very fair, I’ve been dealing with tiny tanks where I hate giving up space and have been trying to minimize space used for additional filtration to make more room for the important stuff like corals! It’s bad enough I have to at least have a pump in there!

[mcarroll]

6 hours ago, Sprinter70 said:

This is very fair, I’ve been dealing with tiny tanks where I hate giving up space and have been trying to minimize space used for additional filtration to make more room for the important stuff like corals! It’s bad enough I have to at least have a pump in there!

I hate ask, but have you read up on how they did it before pumps were invented?

[Sprinter70]

2 hours ago, mcarroll said:

I hate ask, but have you read up on how they did it before pumps were invented?

There may be a creative solution there somewhere, I thought they used air lifts, but there may be others techniques. Either way, I think it’s fair to say pumps are the most effective for their size and noise. If you have some idea for Acro level flow in a 1 gallon cube…I am all ears! This was not the problem I sought to solve, but after starting 6 picos and only having uglies in 2 (1 of which was dry rock) there may be something beneficial that, as a researcher, I almost feel obligated to follow through with.

[patback]

4 hours ago, mcarroll said:

I hate ask, but have you read up on how they did it before pumps were invented?

People have been keeping coral before pumps were invented?

[mcarroll]

8 hours ago, Sprinter70 said:

I thought they used air lifts

I think air pump technology was around, but not sure if it was commonplace or (I'm guessing) mostly industrial.  Either way that's not what I was imagining.  🙂 

 

6 hours ago, patback said:

People have been keeping coral before pumps were invented?

In the main book linked there from the period, Gosse (c.1855) describes an intriguing mechanism for tank flow using gravity and a container of tank water strategically suspended over the tank.

 

They were keeping a variety of "reefy" critters....whatever could be found in the sea nearby.  Make sure you check out the color illustrations he made for many of them!  The illustrations are as interesting as the ways they did things.

[Sprinter70]

Well, I ordered the Dr. Tim’s nitrifying bacteria and ammonium chloride for the cycle testing. The big question now is: will a generic black rock from petco (https://www.petco.com/shop/en/petcostore/product/imagitarium-aquatic-black-lava-rock-3617399?store_code=1843&mr:device=m&mr:adType=pla_with_promotionlocal&cm_mmc=PSH|GGL|CAL|SBU05|0|OB-Imagitarium|oESzLma28ENV6J7sw4F1Ar|||0|0|||18273424038&gclid=CjwKCAjwvdajBhBEEiwAeMh1U41NafwuICnJ1YOGiWL-jtR-TLQ5Tky6aXaYOfFgiXvKBhWInWvLohoCh2YQAvD_BwE&gclsrc=aw.ds) suffice or should I get some standard Marco rock or life rock from the LFS. If I go with the latter, I will not have the same(ish) color rock, does that matter?…. What does everyone think????

[Sprinter70]

I am going to proceed with starting the experiment, I can always reset and do another replicate or change something that I find questionable. I will follow the recommendation on each of the bottles for cycling and test parameters each morning (evenings when I can) until each tank completes the cycle- ammonium and nitrate testing. To start, I will make one batch of salt, add the Dr. Tim’s bacteria and ammonium chloride solution to the total volume and then fill each tank after mixing well. Temps will be maintained at 24.5 to 25C and tanks with be protected from any incident light. Never too late for suggestions for this round or another, should be fun!

[Sprinter70]

It’s up and running, have my waterline marked for periodic topoff. Specific gravity of 1.026, ammonia at about 2ppm, nitrate at 0 (as expected from fresh mix), 6ml of Dr. Tim’s, 20 drops of the ammonium chloride, all mixed and tested before evenly pouring between the tanks while mixing and marking that high water point.

[Sprinter70]

Day one- no difference (blue=plastic, red=dry rock)

[mcarroll]

Still not totally sure what you're trying to test or learn, so I'm just throwing out a few thoughts and ideas here.

• If you haven't read up on the "problems" with fishless cycling" that are fairly common, now (during the wait) is a great time. 🙂   
• "fishless cycling" is not a foolproof process by any means.  While it has its merits, it is not better than most other methods, presuming you do any of them right.  It's just different.
• Dr Tim has a nice list of minor "gotchas" related to "fishless cycling", which include the fact that "fishless" tends to take a little longer.  Check it out here:  https://www.drtimsaquatics.com/blog/cycle-troubleshooting-13-things-you-need-to-consider/.  
• It's worth searching for a few meaty forum posts where problems were experienced too.  They are very numerous.  Probably pretty interesting for your test here too. 👍
• Depending on your goals, it seems like you'd want to experiment with "untreated" rock samples....aka "the natural method"....where you don't use any additives, and just watch the cycle progress through it's 30-40 days naturally.  Critter proportionate to the tank size will be required.
• Obviously – right? – since until the bio-filter is grown in you are totally reliant upon dilution, pH and temperature to protect the critter from more-toxic NH3 ions....and almost all of that protection is in the dilution, so you keep the bio-load small.  In most tanks, one snail (small) or one hermit crab (small) is sufficient. 👍
• Could be interesting to see if the plastic media has any effect on the natural 30-40 day timeframe.  We know "fishless" takes longer.  Would be interesting if plastic media was dramatically faster or different somehow.
• There are tons of articles like this there where they study the effect of different medias for use in bio-filtration:
  https://www.sciencedirect.com/science/article/pii/S0959652622025227
• That one happens to be looking at plastic media vs coconut shells, for example – check it out!  But search or Google Scholar or whatever and you should be able to find quite a few other articles like it.  👍

[Sprinter70]

I am just running a test to see if the way I make the plastic rocks provide more sheltered surface area to favor the microbial growth that leads to completion of the cycling process. I already have tanks with it, and have not had issues in the past with fishless cycling. Now I just want to see if I had an advantage using this material.

[Sprinter70]

So today is the first day with a difference that can be observed. Red tape is store bought rock and blue tape is my plastic rock.

it is only a slight difference but my caveman eyes tell me 1ppm for store bought and 0.25ppm for plastic, I’ll try and do a nitrate test tonight and update. It does look like both are starting to cycle as the levels are lower than 2ppm in both tanks. I figure once they are both cycled, I can add a set amount of ammonium chloride to see how they hand a quick injection. Overall, tanks have been rock solid stable for temperatures over the course of the whole test, top off has needed to happen once and both tanks needed the same amount (I have them covered to reduce the need for top off).

[Sprinter70]

As promised, did a nitrate test, but no difference in nitrate. I do not have a nitrite test kit, so we will be waiting for 0 ammonia and an increase in nitrates.