Why point powerheads towards surface?

[nashvillian]

If you are going to point flow upward, make sure the pump is strong enough so that you aren’t getting dead zones with little flow. You’re going to lose a lot of force if the pump is too small, effectively pushing the same water around on top. Water movement is more important than surface agitation for gas/nutrient exchange, especially if you’re running a skimmer, the needle/bubble/Venturi effectively creates a secondary surface inside the cylinder.

 

[alex.mccann99]

If you are going to point flow upward, make sure the pump is strong enough so that you aren’t getting dead zones with little flow. You’re going to lose a lot of force if the pump is too small, effectively pushing the same water around on top. Water movement is more important than surface agitation for gas/nutrient exchange, especially if you’re running a skimmer, the needle/bubble/Venturi effectively creates a secondary surface inside the cylinder.

I've posted about this before, but one of the coolest things I've bought in a while is this (VFG) Variable Flow Generator. I have it pointed slightly upwards so the current breaks the surface and generates variable Flow in a large amount area.

 

[KenO]

I have my flow pumps pointed to the surface, I also had my air line for my skimmer plumbed to bring in outside air. My pH levels were always low 7.7-7.8. I removed my skimmer and added an algae scrubber. My pumps are still pointed to the surface. Now my pH levels with the algae skimmer are 8.1-8.2 solid.

 

[Somuchflo99]

If higher O2 levels are what you're after, lower the temperature is a easy fix and more beneficial than a powerhead pointed at the surface

lower by how much

 

[saltyhog]

I have my return lines pointed at the surface. That way I can use my power heads to optimally achieve random flow patterns.

It also minimizes water back flowing in to the sump when the return pump is turned off/power outages. My sump can hold all the water from the returns and if I pull standpipes I can drain the overflow without endangering an over flowing sump.

 

[DeL]

I'm guessing vortechs are out of this question? since they create random flow patterns, then no need to be aimed anywhere right ?

 

[Idoc]

It adds to gas exchange.
Depending on where the head is placed and type of head it can actually add to the mass water flow.
I.e. A Koralia has a fairly narrow flow. Lower it , point it up, and after it hits the surface it spreads out.

Good trick for cheap pumps.

I have 2 Koralia powerheads in my 75g... so best to place them lower in the tank? I have them both about 8 inches under the surface... one angling slightly down across the back and the other slightly pointing up to the surface shooting across the front.

 

[saltyfilmfolks]

I have 2 Koralia powerheads in my 75g... so best to place them lower in the tank? I have them both about 8 inches under the surface... one angling slightly down across the back and the other slightly pointing up to the surface shooting across the front.

So hard to say. It's tank to tank and rock work too. Plus the size of the head.

I love having flow behind the rock btw.


Fwiw. I've had my 55 for 3 years and the flow is almost right.

 

[Bruce Burnett]

I have about 20,000 gallons of flow within my display none of my pumps are pointed up as there is already plenty of surface movement. I have too much co2 in the home so skimmer pumps pull air from outside. Air stones create too much salt creep.

 

[Randy Holmes-Farley Verified Community Expert]

lower by how much

I'm not sure I'd lower temp to increase O2 (as opposed to aerate more), but going from 25 deg C (77 deg F) all the way down to 20 deg C (68 deg F) increases the max amount of O2 that can dissolve from 6.9 to 7.6 mg/L (a boost of 10%).

See Table 1 in this article:
http://reefkeeping.com/issues/2005-06/eb/index.php

In a subsequent article, Eric showed the effects of different types of aeration and light cycle etc. on O2:

http://reefkeeping.com/issues/2005-08/eb/index.php

 

[brandon429]

Wow thank you for posting that

The most interesting part to me was the measure of BOD from a lr sample in a controlled environment

Pair that with its castings and detritus production known from live rocks stored in cleaning buckets

We can literally see live rock breathing and respiring with the charts, it changes away from live rock into collection of unseen animals with that data. Lr is a tax in certain ways along with its benefits. airstones are darn fast oxygen facilitatortots

 

[nashvillian]

I heard houseplants increase the availability of O2 indoors [emoji848]

 

[cgdcinc]

Popping bubbles=salt mess everywhere

 

[brandon429]

One handy trick:

For anyone wanting that oxygen blast or surface breakup benefits from air, try it not using an airstone just straight airline bubbling and the dynamics change yet again measurably. this may not be needed until an emergency comes up, but straight bubbling with no airstone on the tubing is indeed working better in my air-driven setup.

1. Saltcreep stops
2. Same surface boil benefits but without micropops
3. Noise comes into play. Louder but benefits are worth it for those using air (nearly all pico reefs on the planet)
4. Though it's the same amount of air, somehow evaporation greatly slows via single large bubbles
5. Light diffraction stops

My pico reef has used only airstone as power for twelve years. Just last month Maritza vase reef talked me into trying straight bubbling for those reasons above they discovered

I prefer this way now though I miss the quiet and simple looks of microbubbles, I liked them and they didn't harm my corals. the reason we use airstones in 99% of pico reefs online vs powerheads is due to the gas exchange we need, due to using lids that will restrict all evap if not pressurized from up under

since it gave me up to a week in between tank topoffs now vs twice a week, Ill stay with straight bubbling thanks M for the tip. I would have never ever guessed removing the airstone would further change pico reef biology while keeping the systems totally on air still. literally the size of bubble displacement changed the topoff in a shocking way, a doubling of efficiency. right under our noses the whole time, Maritza found it.

Natalia's bubbled bowl, zeovit quality micro pico imo

Martizas
Maritza's vase is the most sps/lps diversity kept per unit of volume ever in a reef tank, I bet.


the thing people do to verify co2 retention in their water samples is the sole way we run our whole reef. both those bowls beat any reef on this entire board in terms of salinity stability and do not use ato for any measurable timeframe=neat
solely due to being air driven, its a wonderful mechanism

consider the redox support and overall oxygenation constants of those tiny bowls compared to a powerhead driven reef, based on the link Randy provided above. the homes where these bowls are located were already verified pre design to have safe co2 levels (pH testing) such that bubbling is a direct benefit in these cases. my own house is elec and well vented/g2g for co2. ive actually never come across any feedback saying a gas heated house or a house with lots of people could not run a reefbowl, though the effects are detailed for years in larger tanks using probe measures

something about the constancy of turnover and our weekly water changes still pretty much removes + ambient co2 homes from having much concern with pico reefs. if they're that prevalent of an impact on larger tanks, we'd have heard something by now from a pico aquarist.

 

[Randy Holmes-Farley Verified Community Expert]

I heard houseplants increase the availability of O2 indoors [emoji848]

No, they won't make any useful difference. Even if they converted all of the 400 ppm CO2 into O2 (boosting O2 by 290 ppm), that is a trivially small amount of O2.

Even if that happened (it doesn't), O2 will only rise from 209,500 ppm to 209,790 ppm, or a boost of 0.14%.

We know that doesn't happen because no one has pH too high due to low indoor CO2.

 

[nashvillian]

Oh. I was joking. Your math is off.

 

[Randy Holmes-Farley Verified Community Expert]

Oh. I was joking. Your math is off.

Huh?

 

[EriksOasis]

I’ve never had a ph issue. But you’re saying a bunch of house plants(I have a dozen or so) won’t increase Oxygen levels by much anyway?

 

[Randy Holmes-Farley Verified Community Expert]

I’ve never had a ph issue. But you’re saying a bunch of house plants(I have a dozen or so) won’t increase Oxygen levels by much anyway?

As I showed, the effect of house plants on O2 is totally insignificant regardless of the number of plants.

The effect on CO2 might not be insignificant, but it would take a place the looked like a greenhouse to offset elevated CO2. Think of it this way:

Take all of the food you eat yourself and your family and the food you feed to tank, dogs, etc., (not to mention gas stoves). It all ends up as CO2. For plants to take up that amount of CO2, they would have to grow in mass similar to the mass of food consumed. Very few people have enough daily increase in plant mass to match the CO2 produced. Hence, CO2 will rarely be lower than outside.

 

[nashvillian]

As I showed, the effect of house plants on O2 is totally insignificant regardless of the number of plants.

The effect on CO2 might not be insignificant, but it would take a place the looked like a greenhouse to offset elevated CO2. Think of it this way:

Take all of the food you eat yourself and your family and the food you feed to tank, dogs, etc., (not to mention gas stoves). It all ends up as CO2. For plants to take up that amount of CO2, they would have to grow in mass similar to the mass of food consumed. Very few people have enough daily increase in plant mass to match the CO2 produced. Hence, CO2 will rarely be lower than outside.

All of it ends up as CO2? Doesn’t a portion of it end up as water?