I love this product! I have many aquatic snails and snails produce a LOT of waste in my tank, causing cloudy water. This has cleared my tank up, and helped my plants to grow healthier and stronger! My only complaint is that it took a month to receive my package.Excelente compraDidn't workWhile an overstocked tank is not a good thing this product definitely helps. I've noticed water stays clear for longer when I use this product.Fish seems to happy and healthy.Whether if you go to your local pet store or ur a beginner and go to petsmarts. This product is accurate and cheaper than the stores and it definitely works for its intended purpose, just make sure if you go with API you sticks with the same brand for everything else.good for tank. works well.Easy to use, good for keeping the ph in the tank balanced.Really quite upset. Purchased this bigger bottle as it is better value for money. I had previously had the bottles half the size and have never ever had any issue in particular no leaks. You can see from the first photo that the product had seeped out losing over 100ml of the fluid. As it has to be shaken I could not be sure what part of the various properties had been lost and therefore it was not fit for purpose. Amazon said they would send a second product out. I thought all was good but on opening the courier had clearly let the wet packaging dry out as it had a stain on the outside and the inside of the packaging was covered in white dried on fluid. In both cases this was showing on the bottle also and the seal was broken. Very concerned that someone is tampering with the product and could have added something nasty or may be a faulty batch of unsealed bottles, either way both bottles have had to be disposed off as I could not risk using them in my tank. Very disappointed and out of pocket!Tastes terrible, gave the servant a glass and she spat it out! Right into my fish tank! She hasn't been out of the cage all week, fish seem alright though!I cleaned my Aquarium filter too well recently, as after this I started to get an immediate build up of brown algae. Then added several doses of this product and it prevented the return of the algae in a very short period of time, so well worth the expense and will definitely be buying again when needed.I was sceptical at first as it's hard to prove that it was doing much as I began using it after resurrecting a tank that was left to wallow by a colleague. How does one know which of the cleaning products and techniques are keeping things clean?I recently ran out of this and it’s taken me about a month to get round to getting some more. In that period the tank hasn’t turned into a jungle but I have noticed that it is slightly dirtier than when I was regularly using this.The cap has a built in measurer, I use a cap full once a week on a medium 50 litre tank with 1 goldfish and 3 snails in. Combined with regular water changes this product keeps things nice and clean, and even when I’ve missed water changes – using this helps maintain a reasonable level of cleanliness.It’s priced the same on here (£7.98 at time of writing) as the smaller bottle is in my local pet store so no complaints there.I add this to my treated and denitrated water before I siphon the water into my pond. Although I can't directly ask the fish how they are feeling, Stress Zyme clearly benefits the water quality and boosts the beneficial bacteria that live in the filter.