Tetra Crypto (Cryptodun), 10 tablets are tablets for feeding aquarium plants through their roots. According to the description, they support healthy root development and contain iron and other trace elements, and the nutrients remain available to plants for a long time. The tablets meet the requirements for aquarium substrate and help important micro-organisms develop in it, contain no nitrate or phosphate, do not cloud the water and, according to the manufacturer, inhibit algae. The dose is 1 tablet per 20 l of water at first use and 1 tablet per 40 l at water changes. A pack covers 200 l at the first application.
Key specifications
| Parameter | Value |
|---|---|
| Type | root tablets |
| Elements | iron and trace elements |
| Nitrate and phosphate | none |
| First use | 1 tablet per 20 l |
| At water changes | 1 tablet per 40 l |
| Cloudiness | none |
| Quantity | 10 tablets |
Pros
- Feeds through the roots. Exactly what rooted plants need.
- Iron and trace elements.
- Long-lasting. Nutrients stay available for a long time.
- No nitrate or phosphate. Does not feed algae in the water column.
- Does not cloud the water.
- Supports substrate micro-organisms.
Cons and what to watch
- No ingredients. How much iron and which trace elements is not stated.
- Unclear interval. "At water changes" could mean every change or occasionally; it does not say.
- Placement not described. The card does not explain how and where to insert the tablets.
- "Prevents algae" is an exaggeration. Algae depend on light, feeding and water changes.
- Only 10 tablets. A large tank will use them up quickly.
How to insert the tablets
Push a tablet with your finger into the substrate next to a plant's roots, a few centimetres deep, so it is fully covered. Spread tablets evenly around the tank, close to plants with well-developed roots. At first use, take 1 tablet per 20 l of water, so 3 tablets for a 60 l tank. At later water changes use 1 tablet per 40 l.
Which plants need them
Root tablets are especially useful for plants that feed through their roots: cryptocorynes, Amazon swords, aponogetons, vallisneria and sagittaria. Mosses, ferns and floating plants hardly need root feeding; liquid fertilisers such as Tetra PlantaMin suit them better.
Roots and water together
In a tank with mixed plants it makes sense to combine root tablets with a liquid fertiliser: the tablets feed rooted plants through the substrate, and the liquid feeds plants that take nutrients through their leaves. The key is not to exceed the doses and to keep an eye on algae.
Light
Without enough light, fertilisers will not work. For small tanks with undemanding plants, a light such as the AquaLighter Nano is one option.
Substrate
The tablets work best in medium-grain substrate where roots can spread. In very fine sand or coarse gravel without an intermediate layer, root feeding is less effective. When vacuuming the substrate, avoid the root zone where tablets have been placed.
Signs that feeding is needed
Slow growth, pale or yellowing leaves on rooted plants and poor rooting of new plantings are reasons to consider root feeding. If the tablets do not help, check the lighting and water parameters, for example with Tetra Test 6in1 strips.
New tanks
When setting up a new tank, the tablets can go in at planting time. How to set up a tank properly is covered in aquarium for beginners: what to buy and how to set it up.
Storage
Keep the pack closed in a dry place out of reach of children.
Who it suits
Tetra Crypto suits freshwater aquariums with rooted plants such as cryptocorynes and Amazon swords, especially when planting new plants and setting up a tank. Other products are in the fish medicines and water care section.
Verdict
Tetra Crypto is a long-acting root tablet with iron and trace elements, free of nitrate and phosphate, that does not cloud the water and helps rooted plants establish and grow. The downsides are undisclosed ingredients, an unexplained "at water changes" interval and no placement instructions, an exaggerated algae claim, and 10 tablets will not last long in a large tank.
FAQ
How many tablets should I use?
1 per 20 l at first use, 1 per 40 l at water changes.
Where do they go?
Into the substrate next to plant roots.
Do they contain nitrate or phosphate?
No.
Do they cloud the water?
No, according to the description.
Which plants need them?
Rooted ones: cryptocorynes, Amazon swords, vallisneria.
Can they be used with a liquid fertiliser?
Yes, the two complement each other.
How many tablets are in a pack?
10.
