I always buy this one and it dose what it supost to do. Just don't ad tomany fish at once and am good

When starting out, I had some stubborn imbalances in my tanks. I’d tried other live bacteria products, but using copious amounts of this helped immensely.

I have used this on two different tanks and has done nothing

While I appreciate the shipping speed of this product, tetra Safestart does not work as a bacteria starter. Bacteria must be shipped in special conditions to be kept alive (specific temp) This was bad planning on my part, but I have learned my lesson. Fritz zyme 7 is likely a better option for bacteria because it has instructions on keeping the culture alive so that your not pouring dead bacteria into an aquarium like I did. I will continue to shop at petco but not for this product. Thank you.

Have used in the past & will continue use with new aquariums or when adding fish to an aquarium.

This product should be called "Bottled Cycle". It's miraculous and it 100% works, every time (unlike API Quick Start or Seachem Stability). I've cycled three tanks with it. None of thrm took longer than 6 days. Don't skimp, though. Pour the wholes bottle in (no less than 24h after you've used Prime or another water conditioner, since Tetra claims they reduce SafeStart's efficacy).

This product is a "go to" for aquarium cycling and adding beneficial bacteria boost to the tank as filters are changed. I highly recommend this product.

TL,DR: Cycled my 10 gallon tank in 72h. I've been fish-in cycling my 10 gallon tank for three weeks, and I was at my wit's end with a Nitrite spike (over 5 PPM) that has lasted for two of those weeks. My whole life was being affected by it, because of the huge guilt and anxiety of doing a fish-in cycle that seemed to be completely stalled in its second (and last) stage. I thought I had kickstarted the cycle by doing a 7-day treatment with Seachem Stability. I was wrong. Then I went for API QuickStart. No change. Next was Microbacter Start XLF. Nitrites still thriving. All of them miserably failed in creating a nitrobacter colony (one that transforms Nitrites to Nitrates). Last night, at 9 pm, I added one 3.38 fl oz bottle of Tetra SafeStart Plus to my tank. Today, at 12pm I'm getting 0.50 ppm nitrites. I hadn't seen a low reading like that in 14 days. SafeStart has done in 14 hours what every other product couldn't do in 14 days! Ammonia did not spike at all after I added the product (I had an established nitrosomonas colony already). Nitrates are around 30-40 ppm for now. According to product specifications, I shouldn't do a water change for at least 7 days, so let's hope it doesn't go far beyond that. According to Tetra, the efficacy of SafeStart is not ideal if it's mixed with Seachem Prime, so you must wait at least 24h after your last water change with Prime before starting SafeStart treatment. Already back to say that less than 72h since initial treatment, my tank is officially cycled. Miracle in a bottle. This product has saved my mental health. I can finally breathe. P.S.: Despite the crazy high Nitrite readings, my fish were fine (one Betta, six Harlequin Rasboras). Their behavior was never altered. I was doing 50 to 90% water changes DAILY, adding Prime (some times at double dose) and Aquarium Salt (which helps protects fish from Nitrite poisoning). The water changes never reduced the nitrites to less than 2ppm, though, so you can imagine how bad that spike was.