Chemical maintenance protocol for swimming pools and spas

This protocol sets out the sequence of work for keeping swimming pool and spa water within bathing parameters: measure, correct the pH, chlorinate (or brominate), prevent algae and clarify by flocculation. All doses come from the technical data sheets of Instaquim's pool products. The order matters: a pH outside 7.2-7.6 reduces the effectiveness of chlorine.

Materials required

• pH correctors: Instaminus (pH-) (hydrochloric acid 25 %) to lower and Instaplus (pH+) (sodium hydroxide 25 %) to raise
• Solid chlorine: Cloro 90% granulado or Cloro 55% acción rápida for shock chlorination and daily maintenance; Cloro tabletas 90% or Cloro tabletas triple acción for slow dosing in the skimmer or dispenser
• Liquid chlorine for dosing pump: Clor Active 15% (sodium hypochlorite 15 %, complies with the UNE-EN 901:2013 standard)
• Algaecide: Algiquat Basic (quaternary ammonium at 7 %, copper-free)
• Coagulant-flocculant: Instaflok
• For spas and hot tubs: Q Brom (bromine in 20 g tablets)
• Test kit for pH and residual chlorine or bromine
• Plastic bucket, graduated jug and scales for solid chlorine
• Protective gloves, goggles and clothing (P280 statement on all data sheets)

Step-by-step procedure

1. Initial analysis: With the filtration system running, measure pH and residual chlorine (or bromine in spas). Reference values from the data sheets: pH between 7.2 and 7.6 and residual chlorine between 1.5 and 3 ppm (between 0.6 and 1 ppm if maintenance is done with Cloro tabletas triple acción). Note the pool volume in m³.
2. Lowering the pH with Instaminus (pH-): If the pH exceeds 7.6, calculate the tenths to be corrected. As a general rule, adding 10 ml of product per 1000 l of water changes the pH by one tenth (0.1). It can be added via the skimmers or directly into the pool. Recirculate and measure again before repeating; it is a corrosive acid (H314) that must be handled in a ventilated area (P271) and never together with chlorine.
3. Raising the pH with Instaplus (pH+): If the pH is below 7.2, apply the same calculation: 10 ml of product per 1000 l of water for each tenth of pH, via the skimmers or directly into the pool. It is a corrosive base (H314, H290): gloves and goggles, and do not mix with other products.
4. Chlorinating the water: With the pH now between 7.2 and 7.6, choose the format. New or clean water: shock chlorinate by adding 10 g of Cloro 90% granulado per m³ of water (10 ppm) or 15 g of Cloro 55% acción rápida per m³ (15 ppm). Daily maintenance: approximately 2 g per m³ of Cloro 90% granulado or 3 g per m³ of Cloro 55% acción rápida to keep residual chlorine between 1.5 and 3 ppm; with Cloro tabletas 90% in the skimmer or dispenser the same residual is targeted, and with Cloro tabletas triple acción, between 0.6 and 1 ppm. Dosing pump: Clor Active 15% is dosed at a maximum of 3 mg/l of active chlorine, equivalent to 1 l per 50 m³ of water. Tablets must never be placed directly on the liner or the pool floor. The pool chlorine calculator converts volume and target residual into grams or litres of each product.
5. Algae prevention with Algiquat Basic: For maintenance, add 3 l of product per 100 m³ of water daily, preferably by dosing pump; the data sheet states that this dose is indicative and may vary depending on water quality. As an initial treatment, with the pool empty and clean, it is applied undiluted to the pool surfaces and allowed to dry before filling.
6. Flocculation with Instaflok: To remove suspended particles and improve filtration, dose 5 ml per 1000 l of water for maintenance or 20 ml per 1000 l for recovery treatment (cloudy water), always via the skimmers while maintaining a high water flow. There is no need to adjust the pH of the water, but it is not used with diatomaceous earth filters. The Instaflok calculator gives the exact dose for your volume.
7. Spas and hot tubs with Q Brom: Place the 20 g tablets in the brominator and keep residual bromine at 1.5 to 3 ppm by adding daily the amount of bromine consumed according to estimated demand. Check pH and residual bromine daily; bromine does not produce chloramines, which reduces odours and irritation in enclosed spaces.
8. Verification and record: After each dosing, allow one recirculation cycle to complete, repeat the measurement and note the date, volume, product, dose and readings. The daily check of pH and chlorine with a test kit is the common instruction on all chlorine data sheets and the basis of self-monitoring under Royal Decree 742/2013 in public-use pools.

Cleaning the pool shell and the waterline

With the pool empty, Desincpool removes cement, limescale and efflorescence residues before filling: it is used manually at 25 % in water, spread over the surface and rinsed with plenty of water. Avoid contact with aluminium, natural stone and acid-sensitive materials and do not use it in liner pools. For grease on the waterline during the season, Grassol P is used diluted at 2 to 10 % depending on the degree of soiling, left to act for a few minutes and rinsed; it is suitable for all types of metal except aluminium. Vinyl or plastic furniture is polished with Tablex, spraying a small amount and rubbing with a dry cloth. To sanitise pool surrounds, showers and changing rooms, Hipoclorito 15% is dosed at 0.8 to 1.6 % (0.1-0.2 % active chlorine); its data sheet does not cover dosing into bathing water.

Verification and control

The protocol is deemed correct when, in two readings separated by one recirculation cycle, the pH stays between 7.2 and 7.6 and residual chlorine (or bromine) between 1.5 and 3 ppm. If the pH drifts, correct by tenths using the 10 ml per 1000 l rule and do not double doses without measuring. If chlorine drops daily despite the maintenance dose, check bather load, filtration and algae before increasing the dose, and use the Instaflok recovery dose if the water is cloudy. Keep the records: in public-use pools they form part of self-monitoring.

Safety and PPE

• Protective gloves, clothing and eye protection with all products (P280); respiratory protection if ventilation is inadequate
• Never mix products: the chlorines and bromine carry the EUH031 statement (contact with acids liberates toxic gas) and Instaminus (pH-) and Desincpool contain hydrochloric acid. Dose each one separately, at different points and with the filtration system running
• Cloro 90% granulado, both chlorine tablets and Q Brom are oxidisers (H272): keep away from heat and combustible materials; the chlorine data sheets state never to use water on the product in the event of fire
• Instaminus (pH-), Instaplus (pH+), Clor Active 15%, Hipoclorito 15%, Grassol P and Desincpool cause severe skin burns and eye damage (H314); Tablex is a highly flammable liquid (H225)
• Read the label and safety data sheet before each use; keep containers closed and out of reach of children

Recommended Instaquim products

For pH, Instaminus (pH-) and Instaplus (pH+). For chlorination, Cloro 90% granulado and Cloro 55% acción rápida (speed and shock chlorination), Cloro tabletas 90% and Cloro tabletas triple acción (slow dosing) and Clor Active 15% (dosing pumps). Algiquat Basic against algae, Instaflok to clarify, Q Brom in spas, and Desincpool, Grassol P, Tablex and Hipoclorito 15% for the pool shell and surrounds.

Applicable legislation: Royal Decree 742/2013 (technical and health criteria for swimming pools), Regulation (EU) No 528/2012 (biocides), Regulation (EC) No 1272/2008 CLP and Regulation (EC) No 1907/2006 REACH. Clor Active 15% complies with the UNE-EN 901:2013 standard for water disinfection.

Frequently asked questions

How much Instaminus (pH-) do I need to lower the pH from 7.8 to 7.4 in a 60 m³ pool?

According to its technical data sheet, 10 ml of Instaminus (pH-) per 1000 l of water changes the pH by one tenth. Going from 7.8 to 7.4 is four tenths: 4 × 10 ml = 40 ml per m³, which in 60 m³ is equivalent to 2.4 l. Add it with the filtration system running and measure again before repeating.

What chlorine dose does a pool with new water need?

The solid chlorine data sheets state to first adjust the pH to between 7.2 and 7.6 and then shock chlorinate: 10 g of Cloro 90% granulado per m³ (10 ppm) or 15 g of Cloro 55% acción rápida per m³ (15 ppm). Then move on to the daily maintenance dose to keep residual chlorine between 1.5 and 3 ppm.

What is the difference between Cloro tabletas 90% and Cloro tabletas triple acción?

Cloro tabletas 90% is pure trichlor and its data sheet sets the maintenance residual chlorine at 1.5 to 3 ppm. Cloro tabletas triple acción combines symclosene with copper sulphate pentahydrate, does not change the pH of the treated water, is compatible with common algaecides and its data sheet sets the residual at 0.6 to 1 ppm. Both go in the skimmer or dispenser, never on the liner.

How is Instaflok dosed?

The Instaflok data sheet indicates 5 ml per 1000 l of water for maintenance and 20 ml per 1000 l for recovery treatment, always added via the skimmers while maintaining a high water flow. There is no need to adjust the pH and it must not be used with diatomaceous earth filters. The Instaflok calculator on instaquim.com gives the exact volume for your pool.

Chlorine or bromine in a spa?

For spas, hot tubs and whirlpool baths, Q Brom (bromine in 20 g tablets) does not produce chloramines and reduces odours and irritation of the skin, eyes and mucous membranes. Its data sheet calls for residual bromine to be kept between 1.5 and 3 ppm, replacing the bromine consumed daily and checking pH and residual bromine every day.

Can Instaminus (pH-) and chlorine be added at the same time?

No. Instaquim's chlorines carry the EUH031 statement (contact with acids liberates toxic gas) and Instaminus (pH-) contains hydrochloric acid at 25 %. Add each product separately, at different points in the pool and with the filtration system running, and never mix products in the same bucket.