Surface skimming and CO2

Actually...... it's highly recommend.
By most anyone that does a lot of tanks. ADA uses them on larger tanks, his giant tank has them.

I have them.

CO2 is easy to add, you just add a bit more than without surface movement.
The real benefit is the exchange of O2 and better mixing.

I like lots of current and mixing, it's good for plants and reduces algae. There's a lot of evidence of that both in FW and marine systems.

It helps exchange nutrients as well as CO2.

In most cases, like yourself, folks reduce their surface movement and flow down too low. Their fish gasp.
Many blame the CO2.

It's mostly the low O2.

If the plants are growing well, that can off set that*(but only during the day, earyl am, they gasp), if you have few fish, that also can off set that.

If you have good surface movement, etc, then you lose some CO2, so what, it's cheap and you just turn the needle valve a 1/16" of a turn etc.

That way there is plenty of O2 and CO2 and the tank is well mixed, the CO2 is not allowed to build up as much this way and the O2 is not allowed to get too low.

So it's a mix of 3 things really, not enough plant growth/low O2(both plant growth and surface exchange) and too much CO2.

I've found it easier to maintain a stable level of CO2 ina high flow tank, less fish issues and better long term results.

Some folks enjoy suggesting surface movement is bad.
That's rubbish.

You can go over board and make it a torrent, but some slight rippling is fine.
Or if the degassing exceeds the CO2 diffusion system's capacity (that is often what happens and folks complain they cannot get enough CO2 into their tank etc)

When you use a skimmer and over box, and a wet dry etc, you should raise the level in the weir box to about 2-4" drop only.
No more.

The wet/dry bioball tower needs duct taped up so no air exchages in there.
That solves about 95% of any issue.

Regards,
Tom Barr

 

I'm goading Vaughn into a nice article like synopsis

That way we can arrive at some consensus about what to do.

Two vendors on both sides of the pond will sell the KH reference solution diluted down etc perhaps.

Using Bromothymol blue is the best alternative and the vendors should be able to get this in large amoutns as well as small 1 oz sizing as well.

You add 3 drops to 6mls of KH reference solution basically.

Regards,
Tom Barr

 

Yes, the 4 KH solution in 500mls amounts will be sold for about 8.99$. Should last several years. The pH indicator will run about the same and also last several years.

Regards,
Tom Barr

 

Greg Watson's company and AE in the UK.

Regards,
Tom Barr

 

I would never tell anyone to avoid surface skimming.
That's bad advice.

Why?
Let us be practical for a moment.
Light= better light use with SS
Films, less with SS
Better filtration, hides tubing with SS

Why not? Supposedly some claim it removes CO2. If you raise the level inside the over flow, then it does not remove much to ever be an issue, anyways, why is it an issue?

I can easily add a tad more CO2.
If you are sat the limit of CO2 addition, then you have something wrong with the CO2 system(inefficient/not enough flow through/ undersized for the tank etc) not the surface skimmer.

The other safety thing is that the levels of O2 will not drop as much with SS and Wet'drys etc if something goes sour with plant growth or with low plant biomass.
I can bring any plant back that's taken a beating, I cannot bring fish back to life.

Just for clarification:
The HOB skimmers we are talking about are not protein skimmers, they are overflow box surface layer skimmers.

CPR and various other brands are all good, the less amount inside the tank, the better.

I always add a piece of 1/2 cork bark etc to my skimmer boxes to hide the things, then add plants like Java fern etc to the cork using U shaped wire nails/staples.

You cannot even tell what the overflow is after I get done with it.
As far as heavier particulate materials, a large weekly water change removes all that.

You will lose a little CO2, but it's not anything to fret over, it's easy to add more CO2 and cost very little.

I had a 90 gallon tank with DIY CO2 yeast, and a wet dry(unsealed) and used 4 x 2liter bottles changed every other week without issue with very high lighting.

So it can be done effectively even with weak CO2 sources.
But it's much wiser to have a CO2 gas tank system with larger than 40-50 gallon tanks.

You might lose 5-10% CO2 at most, but given the cost of CO2, using it 10 hours a day, and 5-10% loss factor relative to cost, say 15$ for 10lbs of gas, that means you will spend about 1.50$ more per year or to 6months so in added CO2 gas cost.

Oh my wallet hurts
If you gassed your fish or have lower DO levels or loss light levels will add up to more $$ faster I'd suggest.


Regards,
Tom Barr