Sacrilege, I know :O

[parotet]

IMO in densely planted tanks you don't have to be really worried for oxygen as the production of O2 should easily exceed the O2 demand. I think Darrel's approach regarding BOD balance of what you have in your tank helps quite a lot. Do you have plenty of plants? Then you have a good O2 production. Do you enhance O2 dissolution (for example by rippling the surface)? Then you are in a better situation. Do you overstock your tank? Then it increases the oxygen biological demand. Do you maintain your tanks? If you don't do it you will increase de oxygen demand. Do you have good microbes populations and you filter is working aerobically? Then your microbes will be working efficiently and getting rid of organics at a good rate...
I move my spraybar upwards when I'm home to break the surface and improve co2 degassing and aeration. Other folks raise their lily pipes. Others use a air stone at night (it seems the aeration in that case is not due to bubbling but to water surface disturbance). In my low tech tank I also try to ripple the surface and of course I try in all my tanks to renew large volumes of water weekly (2 40% WC weekly). I guess all this, along with some of the mentioned issues, is more than enough for having high oxygen levels in a planted tank. No need to add more complexity.

Jordi

 

[Marcel G]

Exactly as Jordi says. If you have densely planted tank, you probably have a good amount of oxygen in there. And if you reach 100% O2 saturation level, your plants will begin to pearl. So according to this you can have some idea of how much oxygen you have in your tank. For the most sensitive fish the level of O2 should not drop below 50-60% of O2 saturation level. Good O2 levels should serve quite well for aerobic bacteria also to break down organics in a better and fast way. If you use Twinstar then you "pump" O2 into your tank. Using compressed O2 set is quite expensive (much more then compressed CO2 set). Also I think that (molecular) O2 don't affect algae directly, but rather indirectly by boosting aerobic bacteria which work harder to decompose organics. And as to the flow, I would say that most planted tanks use 5-10x circulation per hour (no need to use any stronger ... you don't want to stress your plants and fish by centrifuge).

 

[REDSTEVEO]

Hi parotet, ardjuna,

Thanks for the information in the two posts above. I couldn't agree more with any of your comments about flow, water movement. surface agitation etc and pearling, photosynthesis in heavily planted tanks providing oxygen. My problem is that despite all that I still got the diatom alage, and even with the drop checkers on lime green almost yellow from cranking up the Co2, the plants would not pearl, probably because of the diatoms, hence not enough oxygen.

Bit of a catch 22 really.

Any way things are looking better slowly, just a shame I had to pull out all the Eleocharis Still I was warned about having fine carpeting plants in a discus tank so I have only myself to blame.

So where to install the Koralia powerhead then

Cheers,

Steve.

 

[X3NiTH]

It might be worth getting a small Cherry shrimp tank on the go to breed an army for helping to keep the plants free of debris in your main planted tank. Having the separate tank means you can add reinforcements to account for attrition by fish.

 

[parotet]

Hi parotet, ardjuna,

Thanks for the information in the two posts above. I couldn't agree more with any of your comments about flow, water movement. surface agitation etc and pearling, photosynthesis in heavily planted tanks providing oxygen. My problem is that despite all that I still got the diatom alage, and even with the drop checkers on lime green almost yellow from cranking up the Co2, the plants would not pearl, probably because of the diatoms.

Hi steve

Diatom algae IMO have nothing to do with co2. There is a recent thread in which plenty of potential causes are discussed but IME, at least in a mature low tech tank I own, it was related with the issues above mentioned: too much organics in the tanks due to a poor design internal filter always clogged with plant residues, too much biological demand, microbe population not able to deal with this... In my case a change of filter solved the problem. Blackout and light reduction (it was a low light tank) did not work. Massive and very frequent WC worked (due to adding massive amounts of new water, less debris and high oxygen) helped to reduce brown diatom population.

Another thing. Don't focus on pearling. If you want to see pearling... Well it is not that difficult, just increase your co2 and bomb your plants with massive amounts of light... But what for? Your plants will be covered of algae. I've had many times pearling and BBA algae at the same time, so pearling don't mean a thing. Now I keep medium light levels and my plants only pearl when there is a lot of biomass in the tank. I'm happy if my plants grow and they grow algae free, if plants pearl or not, well it's more beautiful if they do

Jordi

 

[Marcel G]

Hi Jordi,

first of all I know that medium light means usually less problems with algae. But on the other hand, if you have stronger light, then your plants grow more quickly, which means that they produce more oxygen, and thus you are usually more lucky to see them pearling, as they more quickly saturate the water with oxygen. Thus it´s not always bad to use stronger light. If you do it you can still have an algae-free tank, but of course you are in greater risk with algae problems ... so you need big amount of plants, good filtration, good flow, few organics (which can mean few fish) ... good everything. More oxygen can help with organics break down also in your tank. So stronger light could mean more O2 in your tank, which can help in many things. So sometimes, using strong light can be useful and desirable to cure some problems. I myself am using quite strong light (around 100-120 umol PAR at the substrate).

Marcel

 

[parotet]

Unfortunately my "estimated +80 umol PAR + high ferts + high CO2 dosing" experiences have never been completely algae free (not a disaster, but slight problems on bottom and old leaves and difficult areas in the tank). I have only been successful with the following approaches:

- "estimated 40 umol PAR + non regular dosing + non CO2"... this is a classic low tech tank

and it looks I'm doing well with... (yes, this is also sacrilege ):

- "estimated 70-80 umol PAR + high CO2 + unlimited ferts except for phosphates that are being dosed around 1,5 ppm/day instead of the 3-5 ppm dosed until now"

Guys, I know it's not the PO4 to be blamed... but something tells me that I was unable to reach the very demanding CO2 levels I had with super high PO4 dosing and super growth rate

Jordi

 

[REDSTEVEO]

Spoke to someone today who suggested I buy a 'Silicates' testing kit, ditch my HMA Filter and buy an RO Unit instead.

The Silicates theme has been explored already on this forum and apparently completely debunked so I don't think there is much point in discussing it further, although I might explore the RO suggestion.

You guys sound like you know a lot about lighting and PAR readings, and umol whatever that is, I don't I am afraid so I am oblivious to what you are talking about, don't even know how to measure PAR. I do know PAR has also been explored and some on this forum would argue that we should take no notice of PAR readings, not mentioning any names

I have got two light units above my tank, each one with 2 x 54 Watt T5 tubes, 2 x Guisemann AquaFlora and 2 x Eheim PlantGro tubes inside the hood, both are supposed to be the best for plant growth. So far the plants have not been doing brilliantly but the diatomous algae is doing just fine.

I have just experimented with the reflectors and turned all four of them almost completely facing upwards away from the water. The effect is that the lighting looks less harsh, subdued, almost atmospheric in fact. God knows what this doing to the PAR ratings if I knew what they were, but some of the discus that never come out when all the lights are on, or even just one set of them, are now out and swimming around. Normally I only see one or two of them when the lights are on, and have to sit there with no tank lights on just watching them by the light in the dining room, which is not what its supposed to be about.

Today I also looked at the Eheim Plant LED lights which can be retro fitted using an adapter that fits into the T5 Tube sockets, they look good but very expensive. Nobody I spoke to knows much about them and would not comment, so I don't think I will bother.

Cheers,

Steve.

 

[parotet]

Hi Steve

PAR is the best indicator of the light you have in your tank because it is the light that plants can use for photosynthesis. As a PARmeter is not a device the majority of us own, we use other indicators to understand how intense our light is and which nutrient demand we expect. That is why most of the hobbyists use watts per gallon, watts per liter, lumens, etc. but these measures are not always reliable. Notice that "watt" is just the consumption of a lamp, nothing to do with the photons activating photosynthesis. A watt per gallon rule is useless for LED lights but works sometimes as a good rule of thumb for other lights.
In Ardjuna's website you can see a very good comparison of PAR readings so you can make yourself an idea of what you have:

http://www.prirodni-akvarium.cz/index.php?id=mereni

(use google translator, the English version is not so complete)

Jordi

 

[REDSTEVEO]

Cheers Jordi,

When you measure PAR at different levels or heights in the tank, I presume you do not do this in the water I may be able to borrow a PAR meter from my brother in law. If I have got 216 watts of light when both sets of lights are on 400 divided by 216 = 1.84 watts per litre, or 4.59 WPG, does that sound excessive?

Cheers,

Steve.

 

[ian_m]

When you measure PAR at different levels or heights in the tank, I presume you do not do this in the water I may be able to borrow a PAR meter from my brother in law. If I have got 216 watts of light when both sets of lights are on 400 divided by 216 = 1.84 watts per litre, or 4.59 WPG, does that sound excessive?

No you use a waterproof sensor head in the tank. WPG was based on US gallons, so your 400l is 90US Gal -> 216/90 -> 2.4W/gal which is not low light.

 

[Marcel G]

I use Apogee MQ-200 PAR meter for measuring PAR which sells for about $350 in the US. There is much cheaper alternative in the form of the Seneye Reef (see my article here) which sells for about €150 in the UK. Both are designed for underwater measuments.