Floating plants/lighting

[AquaBarb]

Hi,

Some advise please.

Struggling to keep floating plants alive. Tried water lettuce, frogbit and salvinia and also stem plants such as water sprite and hygrophilia difformis.

Both my tanks have hoods, i use small amounts of liquid ferts the day after big water changes (75%weekly). My stem plants in substrate all grow really well so im coming to the conclusion that maybe my lights arent good enough.

I have a fluval roma 200 so my lights are the fluorescent tubes.

Total novice with lights so is there a certain brand anyone could recommend which i could look up. Ive heard T5/T8's on this forum alot which i think are tubes.
Are this any good? Or is it worth converting to LED's?

Many thanks

 

[Colin_T]

Water Lettuce, Frog bit and Salvinia can rot if kept under coverglass, but Water Sprite and Hygrophilas are normally fine under covers.

How long are the tank lights on for?​

If the substrate plants are growing well, then there is sufficient light for floating plants.

Are you getting any algae growing on the glass or ornaments?
If there is no algae growing in the tank you could increase the lighting time by an hour per day and monitor it over a couple of weeks. If there's still no algae then increase the lighting time again. Continue increasing the lighting times until you get a small amount of green algae on the glass and that is usually sufficient for the tank. You can reduce it a little bit if you get lots of algae.

What is the pH of the water?
Some plants do better in neutral or alkaline water (pH above 7.0). If the plants come from acid water and are put into alkaline water (or vice versa), they might fall apart in your tank. Check with the supplier and find out what the pH is at the plant grower or shop tanks.

 

[AquaBarb]

Tank lights are on 8 hrs per day and my waters ph is 7.4. I do get a small about of algae more so in my smaller tank. Tend to just get algae on the fake ivy on the back wall of the 200.

Tbf the Water Sprite may have wilted due to salt in my water?? Ive been doing small water changes for the past 2 weeks to reduce the salt and the water sprite which id already ordered before adding the salt got introduced half way through the process.

Might try upping the light on time then over the next few weeks then try the water sprite again

Might try a different brand of ferts also

 

[Colin_T]

high levels of salt can kill plants so wait until the salt is gone then try again.

 

[PheonixKingZ]

I have this same problem. My Anacharis is growing FAST, but....the little water lettuce’s I put in there last week have rotted. All of my parameters are in check.

 

[Byron]

This is most likely (from the info posted) a nutrient issue, nothing to do with lighting. But to be certain, can you provide a photo of the entire tank so we can see the plant species and numbers.

While waiting for that...light is not likely the issue because the lower plants are doing well. But we need to see what plants they are, and how they are growing. Increasing thee duration will have no effect on floating plants assuming the duration is at least six hours a day now; reason is, that plant photosynthesis is driven by light intensity (assuming spectrum is OK) and will continue provided the necessary nutrients are available. As soon as one of these is no longer sufficient, photosynthesis will slow. In other words, if the light is sufficient, the plants will grow well under six hours of light or under eight hours of light, or under twelve hours of light, equally--provided there are sufficient nutrients at each stage.

Nutrients has another aspect, the type. You mention using liquid fertilizer, which one and how much? And do you use any substrate tab fertilizers? What is the GH? Knowing these plus the photo should point us to the issue.

EDIT: Forgot to mention, I agree about the detriment of salt, and floating plants are especially sensitive here because they take up substances in the water so rapidly. Not saying this is the issue, and it may be mostly gone now via water changes (could do a few more), but salt is detrimental.

 

[AquaBarb]

Hi Byron,

Plants in at the moment are Amazon Sword, Rotala Indica. The thin leafed stem plants in the back corners im not sure what they are called (close up below) These have all done well.

Ive had Lugwigia Repens, corkscrew vallis in the before which didnt fair well.

Ph is 7.4 Gh 14 gdh

liquid fertilizer i use is Tetra PlantaMin.
Dosage says add 5ml per 20 litres of aquarium water every month which mine works out at 50ml. I just spilt this into weekly doses.

I do use root tabs every 3 or 4 months

 

[Byron]

I still think the problem with the floaters is nutrient-based. The plants are growing very well, so light is probably not the issue. I would not increase it, as algae may rear its head. There would appear to be a good balance of light/nutrients now (for the rooted plants), don't monkey with it.

I suggest this on two counts. First, substrate tabs significantly improve plant growth for plants rooted in the substrate. I have found them amazingly beneficial. I use the Flourish Tabs, and I learned that these added just enough of the "hard" minerals (calcium especially) to compensate for my very soft (zero GH/KH) water, something the liquid alone did not achieve. So they are one benefit the floating plants wouldn't have.

Second, you might try switching liquid fertilizers. I cannot find any data on Tetra's site as to what is actually in the PlantaMin. It mentions a few but then says "other essential trace elements" without naming them, something that always puts me on guard. This liquid supplement may be sufficient with the root tabs, but not sufficient for floaters that assimilate all nutrients from the water column (or air, like CO2).

I have been using Seachem's Flourish Comprehensive Supplement for the Planted Aquarium for over ten years now, with I believe good results. I have during that time experimented with using more, and using less, over several months. Less rather than more is safer, or algae can become an issue. But one benefit of this product is that it contains every nutrient (except oxygen, hydrogen, carbon) that aquatic plants are known to require, and perhaps more importantly, they are all in specific proportions to each other according to the requirements of aquatic plants. [The "hard" minerals are minimal because they will usually be present from water changes.] This is important, because too much of some nutrients can cause problems including the plants shutting down uptake of certain other nutrients. For example, I have killed off the floating plants in one tank by increasing iron, while the lower seemed to manage; I discontinued the additional iron and the plants (Water Sprite) rebounded after a few weeks. It sometimes isn't much that makes the difference.

Brightwell Aquatics' FlorinMulti is a liquid supplement near identical to the Flourish Comprehensive, though I have never used this one.

 

[AquaBarb]

Appreciate that Byron thank you.

I was going to try a different liquid fert so Ill give the Seachem's Flourish Comprehensive Supplement ago.

Some people us Seachem flourish excel aswell. Is this worth trying with the Comprehensive Supplement?

 

[Byron]

Some people us Seachem flourish excel aswell. Is this worth trying with the Comprehensive Supplement?

No. Excel is glutaraldehyde (and water), a strong disinfectant. This will harm fish. Some plants will be killed outright with recommended dosages. If it should get overdosed, it can kill plants, fish and bacteria. Glutaraldehyde is used in hospitals to disinfect surgical instruments, and in embalming fluid...that is how strong it is, and it has no place in an aquarium with fish.

CO2 is usually adequate in a fish tank to begin with; the decomposition of organics primarily in the substrate is the major source. In natural or low-tech method planted tanks, this can be sufficient. There wuld not appear to be a CO2 issue here from the photos.

 

[AquaBarb]

Dont know how these companies get away selling products like this then!

Glad i asked now. Thank you Byron

 

[Byron]

Dont know how these companies get away selling products like this then!

Glad i asked now. Thank you Byron

You're welcome.

We had a thread a few weeks back about products declared "safe" for fish. How one defines "safe" is the key. If it only is to mean that the fish will not turn belly up within minutes of using an additive, that is "safe" to some. I look at the long-term picture. I know every substance added to the tank water does get inside fish, that is scientific fact. It enters the bloodstream and thus to the internal organs. It also enters via the gills. I would like to see these people inject this substance into their bloodstream, and then tell me it is "safe" for fish. Nathan Hill's comment cited in blue in my signature block sums it up.

 

[seangee]

Where are you sourcing your plants. Just one example with floating plants:
I bought several types including frogbit from local sellers (nurseries) via Amazon and eBay. I never had any success (other than duckweed) and thought I just could not have other floating plants. In hindsight I suspect these were grown in outdoor ponds in cool water and could not survive the transition to tropical temps.

I had one last attempt at frogbit. This time I went for a big brand and got a tiny pot of tissue cultured plants. The brand I chose was Tropica 1-2-3 grow. Yes it cost more money for less plants but the stuff went absolutely ballistic. I now have it in 3 tanks, have got rid of the duckweed and salvinia and literally throw out bucket loads of the stuff every week.

This is what I mean https://www.fishforums.net/threads/back-to-black.454283/

 

[AquaBarb]

Thats interesting. All the floating plants ive tried have been sourced via ebay from local sellers etc. Even the duckweed i brought for my rainbows to munch on didnt mutliply like i thought it would.

Might just give that a shot Seangee because i do like frogbit. Hopefully that along with the better liquid fert might work.

Cheers

 

[AquaBarb]

Gents,

Just thought, because i didnt have any sedate fish i added a spray bar in my big tank. This was to help water disturbance/circulation etc.

Would this be a problem for floating plants? Not saying this is causing them to wilt away beacause the same happens in my small tank without a spray bar. Just wondered if this could be another issue?