Converting marine to planted FW

[waterwatereverywhere]

I've got a tank which was until recently marine, but I'm planning to set it up as a planted FW tank, keeping soft water fish. If possible I want to still use as much of my current set-up as possible. This includes metal halide lights and RO water.

With MH light, I heard somewhere that the standard marine 10000K is not suitable for FW, is this right? And with this much light, would CO2 injection be needed, and if so, would the Hagen canisters do the job or would I need an external canister system? - the tank holds about 45 gallons, it's 36x18x18 plus a sump. The only concern I have about the internal canisters is that they would be on all night.

Lastly I would plan to install a heating cable and a layer of laterite or similar nutrient rich stuff, does this mean I wouldn't then need to add fertiliser regularly - how long does this substrate last?

Sorry for all the questions, hope someone can help with any or all of them!!

cheers

 

[Lateral Line]

RO water is not suitable "raw" for freshwater use, it has too limited a buffering capacity and can suffer from wild pH swings. You'll need to use a stabilising salt - something like Kent RO Rite. Once stabilised it is first class stuff, and I use it in all of my tanks. Something to be aware of however, is that the freshwater fish in a dealers tanks are likely to have been kept in tapwater, and will thus require aclimating to your set up, (regardless of the fact they may have come from a soft/acid environment originally), they will suffer osmotic shock if you drop them straight in.

I've never used MH so I'll leave that for someone who has!

The level of light required, and the CO2 concentration are related. Fast growing high light demanding species require high CO2 levels to match their fast metabolism. If you have not already done so, browse Tropica's plant list for species ideas and their requirements.

I don't know these Hagen units - I use Eheim external canisters and they are on 24 hours. Never used a sump either.

I put laterite in under the sand in my tanks and it lasts for years. That said, it is an iron fertiliser and does not contain all the macro and micro nutrients needed by plants. Fertilisers are not needed often however, the fish in your aquarium provide a good deal of the necessary material. Look for a good quality fertiliser that is largely nitrate and phosphate free as these are normally plentiful and non-limiting, (although with that light level - maybe not). Some plants get their nutrients from the substrate, so a tablet/pellet fertiliser for pushing into the sand is also necessary if you keep these species.

I have used below tank heaters and Dennerle heater cables, and although I know the theory, have never found they made any difference.

I assume you are aware that things like coral sand and normal marine set up decorations are not suitable for a freshwater tank such as you propose. I also assume you are aware you need to keep your substrate open to prevent anaerobic bacterial build ups.

 

[waterwatereverywhere]

Thanks very much for the advice!

When adding fish I would normally spend half an hour to an hour floating them and gradually adding water from the tank every five minutes or so - would you say that I should give them longer than that putting them into my stabilised RO water?

I think I misled you by talking about "Hagen canisters" - looking at them again I actually meant the Hagen Nutrafin CO2 units, which do in fact sit outside the tank, my mistake . My concerns were firstly they are cheap - okay, that's not a bad thing but do they do the job?? - and secondly it doesn't say if they can be turned off at night, so it would be producing CO2 through the night.

Interested to see your comments on the substrate and heating cable or not. Can you just explain what you mean by 'keeping the substrate open' - are you talking about 'hand raking' it over regularly to stop it compacting? Yes, I'm not intending to use any of the sand or rocks from my marine set-up. I was looking at a substrate in three layers; some silver sand or lime-free gravel at the bottom, over the heater cable, though now I'll have to decide whether or not to use one! - then a nutrient rich layer like laterite, then some lime-free gravel on top, probably with some bogwood added to the tank.

Thanks again

 

[Lateral Line]

Fish from the lfs go into a q. tank with tap water in it. I drop the water down to my main tank levels over a 2-3 week period. Fish moved from the lfs are stressed enough already - I don't want to add to their troubles. If you have been keeping marines, then the water is generally pretty standard. Freshwater varies enormously in chemistry/mineral content. You'd probably get away with a shorter period, (even the method you are used to using), a lot depends on the magnitude of difference between your set up and the local tapwater.

A lot of people in here, (including me), use home made CO2 units made from soda bottles and air line! They work just fine, and mine run 24 hours. There was a thread recently about Hagen CO2 units.

Keeping the substrate open is I suppose, yes, a bit of handraking. I prod mine around with a chop stick which seems to me to be the perfect tools in a densly planted tank - easy to move about, and airs the sand a bit without wrecking roots.

I use swimming pool filter sand over laterite. I find it's grain size/shape prevents it from packing down. Silver sand packs down very hard after a while and you'll need to work it often to keep it open. Haven't used "gravel" in a planted tank for 10+ years.

 

[Lateral Line]

Just looked for that Hagen thread - would seem to be one of those that was lost in the trouble.

 

[waterwatereverywhere]

Swimming pool filter sand? - is that easy to get hold of, what would it be sold as? - though it might be different here in the UK, I don't know.

I found the Hagen thread!! I'm going to bring it back to the top to see how the folk on there have got on with it since putting it in last December!

 

[Lateral Line]

Swimming pool filter sand - I used to buy it from Surrey Pool Supplies in Camberley, walking distance from my house!

I searched for "Hagen" - !!!!!!