Setting Up

[BigCol]

I'll soon have an empty 75g tank with 25g sump, has been used for marines.

A few questions for you all:

Do i use RO water or tapwater? My tapwater has phophates off the scale(8+)

What filtration could I put in the sump (ceramics, sponges, bio balls?)

Is co2 vital for plants? My lighting is 4 x 54w T5 at the moment.

Ta in advance

 

[Mr Bliss]

I wouldn't use RO for a planted tank and definitely not for the purpose of removing phosphates. Phosphates aren't really harmful in and of themselves. Older literature will state that phosphates cause algae, but this seems to be a thoroughly debunked belief in the planted tank hobby these days. But if you add fertilizers (which you should, with those lights), you won't have to dose phosphates (leaving them out in practice may or may not be an option depending on your chosen fertilization regime).

You have pretty strong lights there. Without CO2 and suitable nutrients you'll most likely end up waging an endless battle against algae. I'd either downgrade the lights or get CO2 injection.

 

[BigCol]

I can easily downgrade to half those lights

 

[drobbyb]

I'd have to agree. Having phosphates in a planted tank are not bad. They will make the plants grow too. A simple DIY co2 reactor would do. There's a guide I think under the planted tanks section. It's really simple.

 

[BigCol]

what does the co2 do?

 

[waterdrop]

CO2 is a basic nutrient that plants use as a carbon source, in addition to the other basic ones they need, nitrogen, phosphorus and potassium. CO2 is the most volatile of the plant nutrients in a tank and that volatility is usually the largest source of algae triggering.

For any given tank situation its a bit complicated and may take some working out. I'd take a bit of time understanding it before taking actions.

~~waterdrop~~

 

[drobbyb]

CO2 is a basic nutrient that plants use as a carbon source, in addition to the other basic ones they need, nitrogen, phosphorus and potassium. CO2 is the most volatile of the plant nutrients in a tank and that volatility is usually the largest source of algae triggering.

For any given tank situation its a bit complicated and may take some working out. I'd take a bit of time understanding it before taking actions.

~~waterdrop~~

Waterdrop is right. Research before you spend money.

 

[OldMan47]

In a 75 gallon, you are likely to find that DIY CO2 is just not enough. I tried it for a while on a 45 and finally gave up and bought a bottle, regulator and diffuser. The price of buying gas is actually lower than buying all the sugar and yeast for a DIY. The real cost of the pressurized system is the initial setup. I am still trying to narrow down the right choice of a diffuser because now my system can actually produce enough bubbles that I want to use it efficiently and get a good diffuser. When it was DIY, I accepted whatever the yeast could produce that day.

 

[waterdrop]

Speaking as one who's never had any (diver's tanks under my tank tank ) I've always thought those reactors that shower the CO2 into the super tiny bubbles just prior to the water going into the cannister filter seemed really great. Not sure if you potentially get re-formation into larger bubbles in the media which might eventually collect and cause some noise at the impeller or not. Also, can't remember why now, but think I remember there might be some other completely different technical argument for wanting the diffuser/reactor out at the output-to-the-tank point...

 

[drobbyb]

Oldman47 is right about the co2 being cheaper in the bottle. Since you currently have no co2 and the startup cost of a bottle may scare you, try the DIY first. If you like it then switch to a bottle.

 

[Mr Bliss]

Also, can't remember why now, but think I remember there might be some other completely different technical argument for wanting the diffuser/reactor out at the output-to-the-tank point...

One argument that comes to mind is that the carbonic acid could damage the rubber parts of the filter/powerhead. Or so they say. This is one of those things in the hobby where I've never been able to figure out whether it's a myth or a realistic concern.

 

[waterdrop]

Oh, interesting! I've never heard the carbonic acid thing. I'm pretty sure whatever thing I've forgotten was a different issue from that. I thought I remembered it was some other "optimizing the co2 for the plants" type of issue, rather than a "damaging the equipment type issue." Oh well...

 

[OldMan47]

A realistic concern, in my mind, is that I don't want any bubbles in my impeller whether they are air or CO2. An air bound filter is noisy enough to drive me to drink so it's not an option for me. That is one reason that I am still researching. The idea of the filter breaking up the bubbles makes some sense but to me the noise would not be worth it. I am stil looking at a reactor with a power head vs a ceramic diffuser as the ideal solution. I'm not sure yet which way I will go but I'm headed to the hardware store today to look for components to build a reactor if it looks like I can.