C02 and the importance of flow and distribution for fish and plants

[Gerryd]

Hey all,

Don't get too excited by the great sounding Title

Nothing scientific from me of course, but two examples may help illustrate some common issues. Please forgive the length in advance...

Example I

I have a 57 gal that has an Eheim pro II G90 (2075 - 280gph) for flow and filtration using an Up Aqua atomizer for c02. I use a spraybar and flow goes from right to left. Over several weeks time, the plants on the RECEIVING end of the flow were MUCH more robust and lush than the other side, where hardly ANY new growth had occured. Blyxa on the left, and Java on the right.

This went on for several weeks and the left side was like a giant and an ant in comparison. It was painfully obvious there was an issue

I installed an MP10 on the left side pointing right. Within 2-3 days, the right side and middle, back areas had more growth than the previous two weeks, well seemed like it anyway...After 1 week, growth was MUCH improved in all areas of the tank.

I have since installed another 2075 canister from the other side that provides a really nice surface ripple and counter flow. The MP10 is used mid-water/back to get the stems..

Example II

Is my 220. A few months back I replaced my twin DIY NW rio 1k pumps with a SINGLE inline NW pump. While it may provide the same C02 content, I lost almost 2k gph by the removal of the twin IN-TANK pumps...At the same time, I introduced a lot of small surface dwelling fish, so the MP40 was turned very low to avoid any stress.

I have twin Pro III 2080 (450 gph) on this and an MP40 as well. The one canister has the NW inline and uses a spraybar to help distribute the c02, and the other canister does NOT use a bar, and is used for surface agitation. The MP40 is behind the c02 flow and pushes it around.

I noticed that SOME plants did well but not all. At the same time, the pencils got stronger/bigger. About a week ago, I started turning up the MP40 flow and I can see a big difference, esp in my beloved anubias coffeefolia. I can really see plant movement/sway all over, but the fish are fine with it. They have areas of quieter waters they can shoal in. I still have plenty available from the MP40...

So, I made no other changes to c02 or dosing or lighting at this time. Just increased and improved FLOW and DISTRIBUTION.

**********

Part II concerns surface ripple.

In my 220, I noticed the fish were breathing rapidly in the morning, many hours after c02 was off. I also noticed that I had removed almost all surface ripple for the pencils. I took one of the old rio nw pumps and placed it on one end and let it rip at the surface. Within 10 minutes, the fish were breathing much more normally. It provides a really nice ripple but of course is visible...

I have since timed this for 20 minutes PRIOR to c02 on, and then 1 hour AFTER c02 is off to degas. Since then, the fish are more active during c02 times, and no more rapid breathing in the am.

The 57 gal had times when c02 was off for many hours, but the fish were acting like c02 was high. I used a rio 180 for surface ripple and it made a big difference after that.

I think the combination of canister filters and no surface ripple, along with c02, was building up over time. With no surface agitation, 02 was in shorter supply.

I have to say that I think this may have been the final piece of my specific growth issues. Most stuff is fine, but some random growth issues, made no sense.

Looking back, I removed flow and surface agitation in my desire to eliminate in tank hardware but at the cost of good c02 distribution and the addition of 02 from the surface.

In the 2 weeks since I have made these changes, it has made a marked and observable difference in plant growth and health, as well as fish health.

I may have had plenty of c02, but it wasn't getting everywhere it should have in the quantities needed.

The fish are not overwhelmed with the flow (we observe and adjust just like for c02) and the plants definitely are responding favorably. The coffeefolia is really doing much better, and the clover areas recently trimmed are recovering more rapidly and densely.

Very happy overall. Pics soon I hope once all regrowth is done. 7-10 days max I hope, both tanks will look really nice.

In both case, it seems like overflow (ha ha), but in reality the cardinals in the 57 are really happy, and the pencils in the 220 are doing very well indeed. I really encourage all to take the higher turnover rates seriously. You may have enough, but may also not be routed optimally.

Best thing is I did no other changes in either tank, so was fairly easy to see an apparent cause and effect

Hope this helps.

Later.

[Tom Barr]

Hopefully this will end your time as a plant killer, and now a plant grower.

Canister filters really cause issues and O2 is a huge factor, it's not just adding more and more CO2, I sound like a broken record...........since that is part of it, but my tanks all use wet/dry filters and surface skimming, in addition to the rippling.

[Gerryd]

Hopefully this will end your time as a plant killer, and now a plant grower.

Canister filters really cause issues and O2 is a huge factor, it's not just adding more and more CO2, I sound like a broken record...........since that is part of it, but my tanks all use wet/dry filters and surface skimming, in addition to the rippling.

Tom,

Thanks for outing me as a plant killer. It is only downoi I am having issues with, all else I can grow....

Yes, I focused too narrowly on only c02 and eliminating hardware.... forgot that the IMPACT of those changes may have a ripple or unintended effect. When I lost the two rio 1k, that was 2k gph of in-tank flow that went with it..

Looking back at my historical pictorial and video archives, I see that my tank did BEST when I had lots of flow, extra koralias, etc.

Here are a few to illustrate what I meant with the 57gal...

First_Upload 306.jpgFirst_Upload 305.jpgFirst_Upload 307.jpg

[David]

Hi Gerry,

I have a few questions for you, if you dont mind:

Is your 57gal 48" long? The tank I am putting together is a 55gal that is 48".

Is the second canister you purchased for your 57 installed with the spraybar moving water left-to-right, with the original going right-to-left? This is how I have planned to set up my spraybars, but for some reason I have it in my mind that the currents after meeting in the middle will stifle circulation in the bottom corners of the tank.

I plan to add a powerhead in the bottom of the tank as well, like you did. -- I've noticed a lot of people who have two spraybars set them up at the ends of the tank moving water from front-to-back in conjunction with powerhead(s) to circulate water in the bottom of the tank more evenly. Do you have experience using both of these set-ups?

My apologies for the bombardment

[Gerryd]

Hi David,

Is your 57gal 48" long?

Nope, 36".

Is the second canister you purchased for your 57 installed with the spraybar moving water left-to-right, with the original going right-to-left?

Yes, but on the left-to-right flow, I do NOT use a spraybar. The outlet is used to add surface ripple 24/7.

I plan to add a powerhead in the bottom of the tank as well, like you did. -- I've noticed a lot of people who have two spraybars set them up at the ends of the tank moving water from front-to-back in conjunction with powerhead(s) to circulate water in the bottom of the tank more evenly. Do you have experience using both of these set-ups?

Most, but not all A lot depends on the hardscape and plant mass/thickets. It will also change over time...You need to really play with it and see. You can use a grass/tall plant to determine how much flow is getting to a specific point. Put the plant where you want, adjust and observe

My apologies for the bombardment

No problem!

[Whiskey]

I too have noticed that flow makes a huge difference in planted aquariums, I once had a 180 planted tank that I reduced down to only 400 gph of flow, after doing so I noticed I had fish mortality rates, and couldn't figure it out for the longest time.

Also my tanks that used only canister filters with an output buried way under the surface have had fish survival issues as well, which left me scratching my head. Now all my tanks include a small HOB filter just for this reason. It may offgas a bit of CO2 but it's easy and cheap to just put a bit more in, and the fish are much happier.

My current 25G tall has a Aquaclear 20 HOB, Fluval 204 (Output through spraybar at bottom, includes injected C02), and a Ehiem Ecco.

My next 75 will include all that, but it's spraybar and reactor is being powered by a 600GPH pump. Both are around the flow rates that would be good in a softie reef, 10X to 20X per hour.

Whiskey